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This is an archive of posts from November 16 - 23, 2009 on the Guru's Den
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Hi There,
last visited this site 5 or so years ago- will have to have a good look round later on. I have been having difficulty tracking down the formula for the radius of a handrail on spiral stairs. Have deviated from strictly doing forge work to a crack at cast iron, steps are now awaiting a handrail!

I have a reasonable grasp of the geometric principles involved, I haven't got round to deriving a formula as I was promised the formula from an aquaintance a while back but I would rather have a tried and tested version to work of. (I remember doing something very similar-working out the increase in diameter of a spring when it was compressed and coming up with two different ways to approach it and being unsure which to follow.)
Many Thanks,


many thanks,
   nic - Monday, 11/16/09 06:28:03 EST

Spiral Stair Bending: Nic, due to being a spiral there is not a true "radius". However the closest thing is if you start with a plan view and use the slope of the stairs (rise and run at the center line of the rail) as if they produce a straight line then apply this to the diameter from the plan view. This would give you the "diameter" as if looking at the plan from an angle. In reality the shape you would see is an ellipse. The "radius" is half the long dimension of the ellipse.

To be absolutely perfect, the "run" is the cord of the segment of the plan radius or the rail center line. This is most easily determined by taking the circumference at this point and dividing it by the number of steps in a full circle even if it is not a whole number (such as 16.5 steps). The rise is a theoretical vertical line so it is what it is.

These two things form an angle as if the rail was in a straight line. The length of the rail between steps is the hypotenuse of this right angle. The "radius" you are looking for is half the plan diameter time the ratio between the base of the triangle (cord) and the hypotenuse.

The "formula" is simple geometry (diameter, cord, hypotenuse, ratio). The solution is derived from an accurate dimensioned layout. The formula is best not reduced to its simplest form as how and where the dimensions are derived is critical. Otherwise it would look like:

cord = (pi * d1) / steps

r = d1/2 * SQR(rise² + cord²)/cord

If the rail does not make a full circle then you can either proportion the plan circumference or use a theoretical full circle in your layout.
   - guru - Monday, 11/16/09 10:07:17 EST

Okay, my acetyl. tank is full, the gauges read tank full when closed and open. When I open the regulator, the line gauge reads about 10. After 30 seconds of use the pressure drops in the line but not on the tank. After 2 minutes of use I have to stop because the gas flow is so insignificant that the oxygen pops it out. What is wrong? Do I have a defective regulator? Is Airgas selling me crappy bottles? I feel retarded having to ask this question, but it is frustrating me to no end and the wife is tired of my expletives and scrap pieces being thrown around the shop.
   - Nippulini - Monday, 11/16/09 10:59:34 EST

Nip, sounds like you have some sort of insect nesting in either the regulator or in the hose. Most likely one of those nefarious little wasplike critters that likes to plug small holes with mud. Or maybe a spider. Or even a bit of chewed-up O-ring. Might be your equipment, might have been in the valve on the tank when you got it. If it's in the regulator I don't know what to tell you, that's an expensive fix. Dunno what to say about the hose either, but those are cheaper than rebuilding a regulator.
   Alan-L - Monday, 11/16/09 13:54:28 EST

Nope.... I'm an idiot. The tank is empty. 4psi was the reading on the tank itself. I picked it up and shook it about.... empty. The O2 reads the same.... on my way to the welding shop. Damn, I felt like I just did this a month ago. Guess I'm using more than I thought.
   - Nippulini - Monday, 11/16/09 14:22:52 EST

Nip, I think you have a clogged line. Probably insect nests. These happen when the lines are left loose, torch head off OR occasionally they will get in through the torch tip if it is large enough.

Wasps and spiders will also build nests in the regulator by getting into any opening. Teflon tape can also cause similar problems.

The tank gauge should not change when you close the tank valve unless you have a leak in the hoses OR the torch valves. Close the tank valve, then bleed the lines to be sure the gauge is working, to bleed the lines the regulator must be set to some pressure above zero. If it does not drop then disconnect the hose from the regulator. If THIS does not bleed the regulator and zero the gauge then look in the port and see if there is something clogging it.

IF THIS does not zero the gauge then remove the regulator from the cylinder. IF that does not zero it remove the gauge from the regulator and check for debris in the small hole in the gauge body.


Crack the cylinder valve briefly without a regulator installed. There should be a blast of gas. This is recommended prior to installing a regulator to be sure there is no dirt in the cylinder valve.

Attach the regulator, back off the adjustment screw and then open the cylinder valve. The high pressure gauge should read cylinder pressure and there should be NO flow out the regulator. If there is flow from the outlet then the regulator seat or needle is damaged. If there is flow elsewhere the diaphragm is damaged.

Screw the adjustment screw in until there is flow. Briefly give it a turn to check for full flow then back off to zero.

Check the hose by blowing through them with the torch removed.

Open the torch valves and blow through the torch without a tip attached. Flow should be fairly easy other than opening the check valves if the torch has them.

Before installing a tip inspect bothe ends for debris.

Install the hoses and torch. Test for flow. Test the torch.

Note that the vapor pressure in an acetylene tank is limited and stays close to 240 or so PSI throughout most of the cylinder's use then starts dropping only when most of the gas is used up. It is not linear. Normally you should not see a drop in pressure on a full tank unless you are drawing a LOT of gas.

Also note that I have had oxyacetylene torches ruined by insects. I have disassembled, blown out, cleaned. . . Once those mud balls or silk balls of web material get in places where they cannot get out the only repair is to disassemble by melting the silver solder joints, cleaning and then reassembling. This rebuild work on torches is now so expensive that it is cheaper to buy new.

To prevent this from happening in some areas you have to religiously bag unused torches and use caps on open lines of hoses and regulators. If you are lucky the clog can be cleared. But often it is the end. . .

This is something not in the books or equipment maintenance instructions.
   - guru - Monday, 11/16/09 14:40:01 EST

Mud daubers are pretty severe in my area. It is said that when releiving one self in the woods in the spring in my area, you have to be very quick or the daubers will clog you up!
Tape or bags works for me to keep them out of hoses etc.
   ptree - Monday, 11/16/09 14:48:05 EST

When I first ran into this problem it was with air hoses. One day I found my spray gun did not work. I had loaned it out and I figured it had not been cleaned. I took it apart and cleaned it. Tested it. No go. I checked the hose and the quick disconnect. They were OK. Reassembled. . no go. I was really pissed at the guy I had loaned it to.

I gave up.

Then a year later I tried again. I cleaned the gun AGAIN taking things apart that were no supposed to be taken apart. No go. Everything seemed free and wide open. If this was a paint clog it was somewhere I could not find.

Then another year later I tried AGAIN. But this time I happened to think about the 3 foot long stinger hose made of smaller more flexible hose. I had taken it off every time I cleaned the gun. I blew through the gun . . . whoosh! No resistance. . . Hmmmmmm. I tried the hose. . no flow! I checked the ends. All clear. I took a piece of wire and about mid way in two three feet of hose there was a mud dauber nest clogging the hose! It had probably been at the inlet and air pressure had forced it to the middle of the hose.

I had been fighting this for three years and was ready to go buy a new spray gun. I was pissed at a friend and stopped loaning him tools. . . And there was the clog in the first place I should have looked . .

The gun works fine now. But I have a couple Victor torches that WERE very good equipment that just quit for similar reasons.

On another occasion I had oil leaking from the rear-axel of my truck. Every time I took it in for service it needed a pint or two of oil. Then one day I mentioned it to a fellow and he asked if I had checked the vent cap. We crawled under the truck, gave it a twist, and mud dauber nest material fell out. We gave is another twist, sprayed in some WD-40 and the truck never needed rear axel oil again. . .

Lots of things have low pressure atmospheric vents including regulators. . .
   - guru - Monday, 11/16/09 15:35:47 EST

Safety Warning: Insects also build nests in fire extinguisher nozzles. This can happen in just a few days. A freshly refilled and inspected fire extinguisher can fail just days after placement. If you have a mud dauber or wasp problem inspect your fire extinguishers often and prior to use.
   - guru - Monday, 11/16/09 16:44:18 EST


Don't feel too bad. I had similar symptoms on a propane tank once (though there's no tank gauge in my set up). I was about ready to start tearing things apart. Turned out I just hadn't opened the tank valve far enough!
   Mike BR - Monday, 11/16/09 17:15:06 EST

Charcoal fires, revisited.
Guru, Thank you for your responce to my questions. I have been thinking about it for about a day, so I still have some questions. My tuyere comes in from the bottom, about 3.5 inches below the surface of my "forge table". So if I used a fire tube I would set that on my forge table, and then fill that with charcoal. Is that correct? If so, then there is enough CO2 coming out of the top that you do not have to worry about the atmosphere oxidizing the steel if it is laying on the fire tube? By your responce I take it that laying the steel on top, the fire is still hot enough to get a welding heat? If I layed up fire brick with no cement, would that be tight enough to work?

Thinking about this I saw a diagram of a brick forge with a very deep pit. I was confused, now I think I understand.

Thank you for all your help.
   Milton - Monday, 11/16/09 17:55:02 EST

The fire tube is sort of a forge accessory and not intended for long term use. Brick would do well for long term use.
   - guru - Monday, 11/16/09 18:51:56 EST

Spiral stairs- Here's another way to do what the Guru described, but it's a little more visual/graphical. I've used the following method for finding spiral stair handrail length and diameter to bend it to several times.

To find the length of the rail: Draw centerline of rail in plan view. Mark starting point anywhere on the circle, call it AB. Find total rise of handrail, call it H for height. Draw a right triangle where one right leg equals AB (circumference of rail in plan view) and the other equals H. Call this line BC. Draw the hypotenuse AC. The length of AC is the length of the handrail, basically you will unwrap a right triangle from around a cylinder.

To make the handrail, take the length of stock we've just discovered and bend it to it's developed diameter, a diameter that when you take the free ends and pull them apart will touch the nose of each tread matching the helix of the stairs.

To find developed diameter: Draw a right triangle where AB is the diameter of the handrail in plan view, BC is the rise of the stairs at 180 deg. (1/2 H), and AC is the hypotenuse. Here is the key- the LENGTH of AC becomes the DIAMETER of a circle that you will bend the stock length from the first equation from. When you pull the ends of the resulting circle apart, you have your handrail.
   Judson Yaggy - Monday, 11/16/09 19:20:36 EST

ive asked before but i need some cheap coal in the alabama area.im a rather young (under 20) and i just need some coal so i can expirement with my creations.ive made a rather crude spear head but it couldnt got hot enough to turn it broght orange just a slicht clowing red with charcoal, anysuggestions??
   dustin c. - Monday, 11/16/09 19:38:15 EST

sorry about the typos i was typing fast
   dustin c. - Monday, 11/16/09 19:39:10 EST

No, you were misspelling fast. . . Get firefox, it has built in spell check.

"Cheap coal" is like "cheap gasoline" or "cheap gold". . .

Fuel is fuel and in our global economy it is rare that any one type of fuel costs less than another per equal energy unit.

Real wood charcoal, AKA lump charcoal, NOT briquettes, is just as good for forging as good coal and was almost the only fuel used for thousands of years. "Cheap" coal may be very low grade, that is, mostly non-combustibles such as clay and minerals. Briquettes are not pure charcoal, they are mostly sawdust and glue with some powdered charcoal for color and powdered coal to keep it alight. . . ahhhh steak broiling on sulfurous fumes. . .

So, unless you want a lot more frustration you want top grade smithing coal OR real lump charcoal. Coal can be ordered in your area from Blacksmiths Depot OR obtained from one of the local blacksmiths associations. Seek them and yee shall find.

Lump charcoal is sold by restaurant suppliers for restaurants such as steakhouses and by some of the "big box" stores.

In almost any case, coal, charcoal, propane or diesel, will cost you roughly the same per heat unit.
   - guru - Monday, 11/16/09 20:08:54 EST

Nip, You might be able to upgrade to larger tanks when You refill. Some gas companies will work with You, some won't.

Along with the hassle of frequently needing refills, with acetylene there is a safety aspect too. You are not supposed to draw over 1/7 of the tanks capacity per hour. That means if You have a 75 CuFt tank You shouldn't draw over 10.7 CFH. In Victor equipment that limits You to a #2 tip [.046" hole in the tip].

This is a serious limitation, practically everyone breaks this rule. For short periods of time You can get away with it. The longer the torch is lit, the more likely You are to have problems.

Propane & propalene are not limited in this way, You can draw them 'till the pressure drops too much to continue use.
   - Dave Boyer - Monday, 11/16/09 20:41:39 EST

Layout and Math:

Almost any geometrical problem can be solved by layout and projection. These are basic drafting skills that anyone building a spiral stair should have. Sadly, CAD programs are not a good tool for doing this. They can be used, but are very slow and cludgy compared to a straight edge and a triangle. The Ancient Greeks believed that ANY true proof could be determined with a compass and straight edge. They were right except solving for certain irrational numbers such as PI.

When I create formulae such as above (a few posts) I do the projection in my head and convert it to simple geometry. In spatial design almost anything can be done using only the Pythagorean theorem, PI and derivations or combinations of the two.

Folks that work in our field need to take an old fashioned drafting class (I suspect art schools still teach it) and pay particular attention to projections. Making projections is 99% of all complex layout in fields such as sheet metal work and applies perfectly to spiral stairs.

When doing large scale design work it is often hard to determine accurate dimensions via layout. However, the layout and projection will get you close. Then when you do the math your values should be the same, just accurate to a few more digits or decimal places unless your layout was very sloppy. One makes a good test for the other.

For calculating complex curves it is possible to convert most to a series of radii with centers on common axiis so that the lines blend perfectly from one to another. The violin, classical guitar and many other sophisticated shapes are recorded this way so that they can be reproduced as well as scaled up and down. Using the correct methods these curves will have absolutely no kinks or abrupt looking changes. By knowing the centers and radii the lengths of the line can be determined to absolutely accurate values. These methods can be used to make a scale drawing for a rail and scaled up to create the final work.

Compass and straight edge. . .
   - guru - Monday, 11/16/09 20:53:47 EST

Dave, Propane IS limited by the draw rate for the same reasons. In both cases a liquid fuel is being converted to a gas by boiling at room temperature. This absorbs energy, cools the liquid and the draw rate drops until the liquid can no longer boil. Folks running forges on small propane cylinders have this problem ALL the time. When the bottle stops producing gas you can shake it and hear the slush. The shaking exposes the liquid to warm sections of the bottle and a little more gas will come out. If you wait until the bottle AND contents reach room temperature the gas will flow again.

For high draw applications like big kilns and hot air balloon burners liquid propane is drawn and evaporated in a heated evaporator (the copper coil on a hot air balloon burner). In some cases the liquid fuel is sprayed into the hot furnace. . . In rocket engines the entire nozzle is a huge heat exchanger that cryogenic fuels are pumped into. The heat of the engine blast evaporates more fuel and the fuel cools the nozzle shell preventing it from melting. . . A critical balance.

The difference between a propane bottle and an acetylene cylinder? The propane is ALL fuel. The acetylene bottle is filled with pumice and acetone, the acetylene dissolved in the acetone. Much less fuel and a pressure drop through the pumice. Propane bottles are also larger capacity as well. But the 1/7th draw rate still applies.
   - guru - Monday, 11/16/09 22:46:03 EST

Meteor Shower. . well, at midnight we saw nothing in a partially occluded sky. No planes, no UFO's no shooting stars. Maybe you guys out west will have better luck later tonight. We will try at 3am but the cloud cover should be 100% by then. . .
   - guru - Monday, 11/16/09 23:28:17 EST

Guru and Judson,

Thanks very much for that- a great help!
   nic - Tuesday, 11/17/09 06:38:15 EST

Meteor light show:
Here in NH, I sat out from 2:25 - 3:15 and didn't see a single shooter. I saw one last night before bed, and then another one this morning, about 5:30 when letting the dogs out.

It wasn't too much of a waste of time, though. Both last night's and the 3AM sittings were in a hot tub.
   - Marc - Tuesday, 11/17/09 07:34:14 EST

Hey Guru (or anyone in the North Carolina area),
I have looked all over the internet trying find a supplier of pine tar or pine tar pitch. I can only find gallon size containers for sale on the interet. I need to make enough pitch for 25 high school kids to use on their sculpture projects. With the current economy, our department can't afford to purchase repousse pitch from a repousse supplier. I need to make it from the recipes available online.
Can anyone point me in a better direction?
Thanks for any help.
   Randy - Tuesday, 11/17/09 07:34:41 EST

Randy, a gallon sounds about right for 25 kids. What are you going to use for tools? That is a LOT of tooling up.

I found these folks. noxudolusa.com

They sell pine tar in two grades and 1 liter and up containers.

Pitch R&D Last spring I bought a "stick" of roofing tar (90 to 100 pounds) to use for the same purpose. I also purchased 25 pounds of fine pumice and heavy aluminum cookware (old Club cookware) and some volumetric measuring tools. I scrounged a precision scale as well. I was short the needed propane or electric hot plate. I also researched penetrometer and durometer measurement tools and had a plan to make one using a dial indicator, special points and a weight platform.

I ran out of time/energy/money to finish the R&D. Actually - I've been spending my shop time trying to finish the power hammers Dave and I started the spring before. . .

There is some debate on the use of roofing tar. My plan was to setup a "pitch lab" and test product using standard methods as well as practical (impactor and mold release). I was going to add small quantities of mineral oil to soften the tar then add various fillers. Then compare samples and try for repousse' (more practical testing) as well.

Currently this plan is on hold until we finish the power hammers and a second project, building an interchangable head 2x72 grinder.


More repousse'

In his book, Adolph Stienes recommends using carpet to backup certain types of repousse' work. We picked up some nice sample pieces with bound edges from a floor shop. They make a great work surface for all kinds of things. I have not tried it for repousse' yet. But they sure are less messy. . .
   - guru - Tuesday, 11/17/09 09:43:09 EST

Marc, I saw one quick one go by from East to Weast last night about 9:30. It barely caught my eye befor it was gone.
Was there supposed to be a regular meteor shower last night?
   - merl - Tuesday, 11/17/09 09:57:49 EST

Roofing Tar: Two things. . . Apparently in the South East it is not used very much anymore and is difficult to find. It took a bunch of searching to find a place that stocked it.

Second. . . it is a PAIN to cut up. An ax is recommended. I was hoping to saw or slice the "stick" of tar into slices of a bout 10 pounds to resell. To start, the "stick" was rather mangled, not a straight cylinder and much shorter than pictured in the catalogs. It was cool weather and we tried to saw it. . . Did nothing except make a tarry mess of the saw blade. We ended up using an ax to make tar chips. . .

So, plans as usual go agley.
   - guru - Tuesday, 11/17/09 10:09:45 EST

Too many projects. . . I also have books to scan and setup and two new features to scan and setup on weekly and daily release schedules (plus coding). . . . still making a server move . . and. . .

Meteor shower is the Leonids on November 17-18. This AM was supposed to be peak but we had 100% cloud cover at that time. . yuan! We watch from the hot-tub as well. great way to star watch - warm and comfortable. Over the years I've seen some great meteors from the hot tub. But not so good recently. But this year we have seen satellites TWICE.
   - guru - Tuesday, 11/17/09 10:29:56 EST

Hey guys, thanks for all the advice. My lines are clear and free, besides my cellar workshop is a very unhospitable environment for pests. I just assumed that there was a problem because I usually refill my tanks once every 3 to 4 months. This time it was about 1-1/2 months, so I found out that I have been using the oxy/acetyl a LOT in the past 1-1/2 months, and it makes sense as I have been quite busy filling orders. Dave, thanks for the info about overdraw on the tanks. When I was at Airgas they just sold a set to a new customer and I help explain the dangers of acetylene beyond 15psi. I was thinking about getting bigger tanks, but then there is the storage problem (my shop is SMALL.. lucky I have room to swing a hammer!).
   - Nippulini - Tuesday, 11/17/09 11:04:53 EST

Having nothing to do with blacksmithing or metal working but, interesting none the less...
I watched what I thought was a high flying air craft going from S.W. to N.E. the other night.
I assumed that from the speed that it coverd the distance that it was well under 10000' and must have been on a desending path to the airport in Green Bay as it is not normal to see air craft flying that low going in that direction.
The odd thing about it was that while I could plainly see the landing light(s)that made it look like Venus moving through the sky, I could see no blinking lights.
About the time it should have started making a more dramatic decent to land in Green Bay, I instead saw the lights fade out all together. I assumed it was because the aircraft was pointing completly away from me by this time.
The most curious thing was that the whole time I watched this, about 3-4 minutes, I never heard a sound from it.
The air was perfectly still and only down to about 55 deg. about 10 PM.
Useualy I can hear even the faintest wisper of engine noise at the lower altitudes and, if this was actualy flying high enough that I couldn't, then it was going unbelievably fast.
   - merl - Tuesday, 11/17/09 11:14:28 EST

Pine tar? Do you mix that with something? The pine tar I buy is a liquid about like honey. I've heard of using a pitch, but that's sorta solid. Whole different animal from bituminous roofing tar.
   - grant - Tuesday, 11/17/09 11:42:55 EST

Merl, A good chance is was a satellite. There are some huge photo survey satellites that cover the entire Earth in a varying pattern. You may only have one chance a year to see them. The thing that makes them very visible is the huge solar arrays. These "wings" are very large and reflective. If turned the right direction they can be the brightest thing in the sky.
   - guru - Tuesday, 11/17/09 11:50:37 EST

Grant, It gets mixed with filler much like making a thick putty or plasticine clay. The heavy pine tar makes a much stiffer composition than oil clay (plasticine) which is made from ground chalk (calcium carbonate) and stearic acid (oil).

   - guru - Tuesday, 11/17/09 12:09:11 EST

Thought that might be the case. Don'cha just love the smell of pine tar?
   - grant - Tuesday, 11/17/09 13:15:35 EST

Meteors in the SF Bay Area, thought we'd have cloud cover but when I awoke at 3:50 this morning, clear sky and stars. Stood on the front porch for a good half hour, but no shooting stars. the 10 yr old asked me to wake her up if there was anything to see.
Just got my hands on a dozen set tools from a garage sale. quickly handled the smallest punch and and the hot cut. Discovered the huge difference in ease using a handled tools. Anxious to use the fuller and set hammer. Pics of the find here. http://www.flickr.com/photos/10735775@N04/4084125451/

   Michael - Tuesday, 11/17/09 14:10:29 EST

Love the mini anvil at the bottom. I have about a dozen or so in my collection... nothing like the 345 8-track tape collection I own.
   - Nippulini - Tuesday, 11/17/09 14:58:14 EST

Yesterday I had my acetylene bottle refilled. I started to heat some steel but noticed a phenomenon which I had never seen before. Some solid substance was coming out of the tip. It formed into small pieces which would then break away, red hot, and be replaced by another piece which would form similarly. The substance appearing looked like wax as much as anything. What is it? Am I doing something wrong? I have been having problems getting the torch to work as I would like. I think that those problems, however, are a combination of lack of experience and a very low quality torch.
   philip in china - Tuesday, 11/17/09 15:05:21 EST

Phillip, Sounds like a very serious issue. . . some contaminate in the cylinder contents.

Note that a low acetylene cylinder or am improperly overfilled one, OR one lying on its side will feed liquid acetone into the system. The acetone may dissolve things that normally withstand the gas. However, the hoses, seals and such should all be acetylene and acetone resistant.

Another thought. They make boron feeder systems for acetylene torches. It is a bottle like and acetylene bottle that the gas bubbled through and puts flux in the gas. Lots of brazing done this way. You might have been given some sort of cylinder designed for this purpose. . . .

In any case. It is VERY weird and I would return the cylinder immediately.
   - guru - Tuesday, 11/17/09 15:16:52 EST

Well, us old-timers remember that one. It's calcium or lime from the production of acetylene from calcium carbide. Really bad with the old acetylene generators. Just forty years ago that was still a common way to manufacture it in this country, bet they're using that process over there. Acetylene is now made in this country mostly from oil and natural gas. Shouldn't be a problem if the torch is adjusted correctly, just a tiny bit leaner.
   - grant - Tuesday, 11/17/09 16:58:23 EST

Grant, when I started in 1981 at the Valve, Boiler, and Ice machine factory, they had a huge acetylene generator room. They had pulled the generator a few years before, and still used the room with its frangible roof to hold the manifolded acetylene bottles that fed the entire boiler shops. Had about 100+ bottles in manifold. Later when I was supervisor of the powerhouse, My pipefitters had to service the acetylene flash traps thruoghout those same shops. Took them about 2 days a month to refill the water, and about 3 days in the fall to switch to antifreeze. about 300 traps if I remember right.
   ptree - Tuesday, 11/17/09 17:57:43 EST

First blacksmith shop I worked in had a mountain of lime in the back yard just from emptying the portable acetylene generators. My dad had one when I was a kid too.
   - grant - Tuesday, 11/17/09 18:17:21 EST

Grant, the lime from the generator at VOGT went on the railroad tracks to soak up the oil that dripped from the shavings filled scrap cars:)
When we installed a real chip shredder and wringer for all shavings, we saved 40,000 gallons of ol a year!
   ptree - Tuesday, 11/17/09 18:55:52 EST

Propane freezes at 310 below zero (Farenheit). If you hear slush in a "frozen" bottle, there must be a *lot* of water in the propane.
   Mike BR - Tuesday, 11/17/09 19:35:09 EST

Mike, possibly. But then at the surface of the propane, which is also often mixed with other gases, the temperature could be that low or low enough for the other compounds to freeze.

Propane stops boiling off at much higher temperature, -44°F.
   - guru - Tuesday, 11/17/09 20:10:11 EST

1/7 rule: The pressure drop is an inconvnience with propane and propalene. Getting acetone out of the cylinder and into the regulater and hoses with acetylene is a safety issue.
   - Dave Boyer - Tuesday, 11/17/09 22:28:06 EST

The safety issue in the above post comes from acetylene torch manufacturer literature. I personally have never had any problems, but I havn't heavily overdrawn cylinders for extended timeframes.

Does anybody have any field experience that would indicate a problem before it became serious?

I didn't know of the 1/7 rule for many years and was happy in My ignorance. Now I am gunshy about using a rosebud or any larger welding or cutting tip.
   - Dave Boyer - Tuesday, 11/17/09 22:46:03 EST

Photo Survey Satellite: Guru that had to be it, it would make perfect sence too. Anything flying that high would still catch the sun at that time of night.
Still dam peculiar though...
BTW I can't wait to start getting the reports from your "repousse pitch" experiments.
I was wondering though, if you couldn't put the pitch "log" you purchased in a chest freezer for a week befor trying to saw it with a 2/3 hook blade or, could you then take the ax cut "chips" and recast them in an old frying pan, cover with wax paper and, sell them as ready made repousse pitch blanks?
Also, I remember when I was a boy and we would get tar on our feet from the hot summer roads, we would have to use butter or cooking oil to get it off. I think if you had a moderate drip of vegitable oil (NOT mineral oil) on your blade you might be able to saw through the stuff.
Rather than use my band saw for the task I would take a 2-3' long piece of an old band saw blade and make a bowsaw frame for it.
Thinking about alternitive backings for repousse, I wonder how a 1/2" to 1" thick slab of neoprein rubber would work?
I would think around 30-40 Duro shore A, might work for a start?
   - merl - Tuesday, 11/17/09 23:34:27 EST

1/7th Rule and Acetylene: Dave, I have not had a problem with it as a safety issue but an operational issue.

Once at a Nuclear plant it was my job to quickly heat the end of a large (10K HP) pump impellor with an oxy-acetylene torch. The torch was about a 1-1/2" diameter rosebud. I told the welders I would need 3 standard bottles or 2 extra large bottles manifolded together. ME, the humble outsider "consultant" was told they had no such thing and there would be no problems. . . I was over ridden by higher management.

SO, in I go in double cottons, ring dosimeters and a respirator. . . have the torch handed in to me through the equipment hatch and then drag the hoses up 24 feet of ladders and over a rail. I wait while my assistants lift off the 6" thick shielding and install a huge 100 ton hydraulic puller. Then I light the torch, play it on the part for about 10-15 seconds and the torch goes out POW! So I go to relight the torch, pop, POW. I yell through the respirator to one of my assistants who are now a safe distance away to ask the guys outside in nice cool T-shirts to check the pressure. . . SURE. . LOTS of pressure. I try agian. pop, snap, POW. . .

I go hoarse trying to get the bums outside to LOOK at the friggin gauge while I try to light the torch. . . FINALLY they look. Pressure drops to about 4-5 PSI while trying to light the big torch and 0 by the time it pops out. . .

I pass the torch out and exit the containment (about a 2 hour procedure) on top of the fact that the double cottons are now saturated with my sweat and I have to get out of the respirator without contaminating myself. . . Meanwhile the rest of the crew removes the puller and replaces the shielding. . .

I REALLY hate when MY "I TOLD YOU SO" kicks ME in the butt. . . It took me several days running around Sacramento as an outsider that knew nothing about the area to find the parts to manifold several cylinders together. By then the welders had managed to obtain two extra large cylinders which I then tested with the torch prior to going inside AGAIN.

So, four days later we try again. The puller is loaded to 90% of what the threads can take, I apply the heat playing it up and down the hub on each space between blades. . and PLunk the impellor pops off. My job is done escept for inspecting the impellor for cavitation damage the next day. There was. The fact was ignored along with other issues. But that is another nuclear story for another time.

I've had the same happen in other less dramatic situations but both times it resulted in a failure and the expense of a large crew for a day. At least it was not MY money or MY hide. . but I had forewarned the "management". Now days I would would simply hand the torch to the "boss" and say, "YOU do it, I'm going to take a couple days off".


The standard little 1/2" rosebud that comes in a Victor Journeyman set is all a large full acetylene cylinder can supply. All the larger rosebuds require multiple cylinders that are full and warm. They will fail when the cylinders are drawn down 30 to 50%. In freezing weather you may need to use triple cylinders rather than double.

For large heating jobs I now use oxy-propane because of the availability of larger bottles and the softer quieter flame.
   - guru - Wednesday, 11/18/09 01:14:32 EST

Rubber instead of Pitch: Merl, it will not work very well. You need the pitch to support the work and be permanently displaced along with the metal as it continues to support the non-displaced metal. This firm support allows controlled working and fine detail. Rubber will not do this.

The saw we tried to use was a long very coarse blade on a jab saw. The tar almost immediately melted and stuck all over the blade. It would have put a band was out of commission until a LOT of cleaning had been done to remove all the tar.

The tar melted so fast that I don't think freezing it would help.

I figured the way to repackage tar was to find a roofer with a tar pot and have small boxes lined with a plastic bag filled with melted tar. But then it becomes a semi-production process. It is very messy smelly stuff to deal with and I didn't particularly want my shop to become a "tar" operation. But I will get around to the research because I have some repousse' projects I want to do and maybe I'll stick with it for a while.
   - guru - Wednesday, 11/18/09 01:38:11 EST

I have seen the above posts about repousse. Remember several years ago when the statue of liberty was renovated ? Well the copper sheath on the outside was made and fitted together using the repousse method. No one in the United States could do the work ( as it had become a dying art ) ,so the U.S. asked the French if there was any company over there that could reproduce the needed sections. They found one company that still practiced this type of work and the workers were sent to the U.S. to replace the outer skin sections and replace them with new ones using the repousse method. I believe this is one reason why ancient art and methods should always be kept alive.
   Mike T. - Wednesday, 11/18/09 04:09:06 EST

I have heard and seen great claims for oxy gasoline. Is it as good as the hype suggests?
   - philip in china - Wednesday, 11/18/09 05:57:34 EST

Now THAT sounds dangerous. Hope you got better acetyl now, Philip.
   - Nippulini - Wednesday, 11/18/09 07:43:32 EST

Oxy-Gasoline: It is great for ONE thing, cutting steel. But it cannot be used for welding or other techniques and the torch is fairly expensive ($800 last I looked).

The primary advantage is the common fuel. They also claim that the cutting swarf is very cool compared to oxyacetylene which will wreck concrete and set asphalt drives on fire.

The primary operational curiosity is that the fuel tank is hand pumped to pressurize it.
   - guru - Wednesday, 11/18/09 09:42:13 EST

amazon.cxx has Imprex Pine Tar - 1 Liter can.
Pine tar is used in the rope industry.
   - bill w - Wednesday, 11/18/09 09:42:46 EST

Pine tar pours like Karo syrup. It is different than pitch, the pitch being thicker and not flowable unless heated. There are repoussé pitch formulas in the older books, for example "Metalwork for Craftsmen" by Emil F. Kronquist. The auther suggests putting 3 pounds of black shoemaker's pitch and one pound of rosin in a kettle over a low flame and stirring with a wooden stick. Add 6 pounds of plaster of paris by sprinkling separate handfuls and stirring constantly. Let simmer for about 6 hours until all moisture driven out and the mixture appears like a shiny black, HEAVY syrup. Chasing pitch can be tempered. Add rosin if a harder pitch is desired. Add a small amount of tallow or turpentine is more softness is needed.

As a horseshoer, on hooves with a leather or composition pad between the shoe and the foot, I would put pine tar and oakum over the sole and frog before nailing on.
   Frank Turley - Wednesday, 11/18/09 11:09:50 EST

...perminatly displaced... Yes, I was wondering about that even as I hit the "Post" key. I suppose any rubber compound that was soft enough to remain perminatly displaced would likely be too soft to provide a good backing and not fill in properly for finer detail work anyway.

Not to argu with you about cutting the tar log BUT, I'm thinking that if this stuff can be "chipped" then it can also be saw cut as well.
I can see that the rapid movement of a recipricating blade would heat the cut zone pretty fast and, if it is melting then it won't be cut.
I think if you keep the blade oiled as I suggest and cut by hand with a bow saw or at least a blade with minimal surface area you may get through it. Of course that creates alot of hand labor that I wouldn't be too keen on either.
STOP: What about an old chainsaw blade stretched tight...?
Consider also that the best way to cut raw meat is when it's semi frozen.
Gee, coming up with ideas that involve alot of work for someone else is easy...
   - merl - Wednesday, 11/18/09 11:17:32 EST

Actually, only a little copper work was done on the statue of Liberty restoration- mainly on the torch. The vast majority of work was forging stainless steel inner supports to replace the 100 year old wrought iron ones that had corroded due to galvanic corrosion.
And while the company was French, a New York blacksmith, James Garvey, worked with them on the job.
   - Ries - Wednesday, 11/18/09 11:23:01 EST

Frnk, I like that recipe. I'm gonna' wright that down but, I'll bet I won't find any "shoemakers pitch" though, What would be an equivelant product?
   - merl - Wednesday, 11/18/09 11:29:09 EST

Merl, I can't help you find a commercial product. I'm in northern New Mexico, and we find natural, amber colored pitch oozing out of our small piñón (pine) trees. It would take a while to scout enough for a chasing block, but with time and patience, it could be done. Indians in the region use piñón pitch as a kind of "glue" for their various craft projects. It is not written in stone that pitch needs to be black.
   Frank Turley - Wednesday, 11/18/09 11:51:21 EST

Merl, we tried hand sawing and the tar packed between the teeth immediately. Then it smears onto the sides of the blade and it welds into the kerf. . Even flooding lubricant doesn't work. .
   - guru - Wednesday, 11/18/09 12:11:16 EST

Guru and company,
I have a small problem I'm needing help with. I have a small acetylene tank such as plumbers use for soldering. It's old and hasn't been used in several years. The valve on the top of the tank will not turn. I have tried turning it in both directions but it's stuck. I know some gases react explosively when exposed to certain lubricants. Would it be safe for me to use penetrating oil on the fitting? Are there any other options I might try before I give up and exchange this tank?

Thanks much.
   Bill - Wednesday, 11/18/09 12:13:59 EST

There are some trees that are pitch gushers; once back in Ohio I was visiting a park where they had done some trimming of the trees and found one that I filled a 12 oz cup with pitch that had oozed out. Must have been a "pitch pine". We were using it for neotribal knife hilting mixed with PHD. (Powdered Herbivore Dung).

I may have to start cutting it with pinon pitch and see if I can get a repousse version. Now that the old electric stove is coming out to my smithy I can experiment a lot easier on such things!

   Thomas P - Wednesday, 11/18/09 12:19:44 EST

Cylinder Valves: Bill, Never use any lubricant on welding equipment. Even if its safe the supplier service guys guys will not touch it and if exchanged you may get charged for the cost of the bottle.

Stuck valves are usually the result of the packing being too tight OR stuck (adhered) to the stem. Back off on the packing gland nut just a little. This should loosen the stem so you can exercise it. If there is gas in the bottle then you will need to snug the packing gland until the valve just turns comfortably then test for leaks using a water based leak checking fluid (soap and water).

Often the packing gland is tightened to prevent leaking without regard to usability of the valve. In this case the bottle should be returned immediately. IF after adjusting the valve to work it leaks, then it should be returned immediately.

These small cylinders are often NOT exchange tanks but privately owned (yours) and refilled as you wait. If there is a valve problem it is at your cost. If you get a bad exchange tank it should be returned with a complaint.

This is a common issue.
   - guru - Wednesday, 11/18/09 13:09:37 EST

I have purchased pine tar pitch from Rausch Naval stores in New orleans- I googled and saw that they are still in business-I purchsed 3 1/2 pound containers- don't remember the price- it was a number of years ago
   - Ray Clontz - Wednesday, 11/18/09 13:39:31 EST

Yes Thomas, I have heard of "pitch pines" though I'm not sure what veriety it actualy is. Do you have to do any kind of processing befor you cook it? I have several pines on my property but I have never seen them give off pitch like that. I'll have to look around the neiborhood I guess, probably in the spring now.
I save all my old electric skillets that have the teflon coating coming off them for "experimental cooking" Good for heating up shrink fit bearings and sleaves too.

OK Guru, no more suggestions for sawing tar from me...

Frank, I have a friend that may be going back to live out in NM. If he does I'll coerce him into collecting me some for Christmas. Thanks.
   - merl - Wednesday, 11/18/09 14:15:16 EST

Merl; get him interested in smithing! Frank runs a top notch smithing school out here and I;m currently president of the NM ABANA affiliate SWABA.

   Thomas P - Wednesday, 11/18/09 15:13:25 EST

Well Thomas, he is already a highly skilled machinist, certified welder, skilled electrician, sculptor, painter, guitar maker, chef and, learning silver smithing. At age 61 he claims he doesn't have time for learning another skill but, I think he's just slacking...
Besides, after my wife, he's my best friend and I'm trying to convince him to stay here in Wisconsin.
Also, I am concerned that if he were to meet up with you and Frank he would be turned to the "dark side" and the three of you would band together to try and drag me down to NM as well and, I just can't have that.
I am one of those people who must suffer through the long, hard Wisconsin winters to prove every year that I am actualy alive but, not quite smart enough to know when to move someware warmer.
One of these years I will get out to Frank's school and to Quad states. I believe ptree has reserved an adult bevy for me at Quad states so I may have to go there first befor the offer expires...
   - merl - Wednesday, 11/18/09 18:16:34 EST

(Powdered Herbivore Dung) Is that what a PHD is?! I never knew that.
Hey Thomas, don't you have a PHD........(incert clever imodicon of your choice here)
   - merl - Wednesday, 11/18/09 18:26:46 EST

Merl, We don't have Wisconsin style winters in Santa Fe, but I do heat with wood only for our living room/kitchen combo. The back of the place is sealed off and cold, so the bathroom there is a real waker-upper. Just a space heater in there. So far, I've burned 1/3 of a cord of wood. P.S. The house and shop are at 7,000 feet. The nearby Sangre de Cristo mountains go up to 10,000+ feet.
   Frank Turley - Wednesday, 11/18/09 19:05:17 EST

I have a BS-CIS and a BS-Geology/Geophysics and most of an EETech associate degree. Or as I put it "some bs for each foot" Only PhD I have is that left by the deer, rabbit and packrats. I work surrounded by PhD's in astrophysics though.

Frank; we've had 5 or 6 fires so far down here in the valley---haven't even cleaned up the mess around the wood pile yet.

   Thomas P - Wednesday, 11/18/09 20:03:48 EST

Jock, I have used the 8 hole rosebud tip that is common in Harris gear without problems from a 74 CuFt tank, but never for a really long time.

I got concerned when I looked up the specks on a Purox A100 tip that at a casual glance appears only a little bigger - 8 [rather large] holes and about 5/8" overall diameter. This tip is rated at 147K BTU, or 100 CFH. To comply with the 1/7 rule one would need a bit more than a 300 CuFt tank couppled to a 390 CuFt tank, the latter being about the size of a 100# propane tank. I lit this tip from a 145 CuFt cylinder, the largest ones I have. This is a lot of fire, but I shut it down after a few seconds because of all the cautions about never exceding the 1/7 rule, which I was exceding by nearly 5 times. I am not set up to manifold cylinders, and I don't want to be.

I have given thought to oxy-propane or oxy-propalene.
VIcopper tried the Oxy-propalene demonstration at Quad State, He thought it worked better than oxy-acetylene for cutting.
   - Dave Boyer - Wednesday, 11/18/09 21:11:40 EST

Cutting Tar - Could You use the "hot wire" idea, a length of old bandsaw blade, teeth up tensioned and insulated energised by a stick welder? Just a thought.
   - Dave Boyer - Wednesday, 11/18/09 21:25:11 EST

Frank, I don't envy you at that elevation. I'm sure it takes alot more work to keep your self warm at the higher elevations.
When I was a boy I had a great aunt and uncle that lived on an OLD farm a bit west of here. The house was beautiful in its simplicity but, still large and only heated by the kitchen stove and a coal/wood stove in the living room and one more up stairs. During the winter they would often have to thaw the water in the toilet with hot water in the morning. It had the biggest kitchen you have ever seen. My great uncle would always bragg that he could butcher a whole cow in that kitchen without diturbing the folks at the supper table...
I sure do miss that place.
Thomas, I do feel bad for you. I work on the weekend shift in a shop that covers 4 acers. With only the five of us there I find myself usualy only surrounded by my own pleasent company...
   - merl - Wednesday, 11/18/09 21:33:29 EST

HOT WIRE: Dave, THAT is what I've been thinking of to cut that stuff!
   - merl - Wednesday, 11/18/09 21:35:32 EST

Im torn between Refflinghaus, and Peddinghaus. Refflinghaus is a garaunteed 59 HRC to over 1 in. Peddinghaus is forged though, but only made of 1045? WHat is the Face hardess of a Peddinghaus? WHich would you reccomend?
   - Jacob Lockhart - Wednesday, 11/18/09 21:37:09 EST

If I had a choice and money was no object I would buy a Peddinghaus. For several reasons.

1) The ARE forged. May be the last forged anvils over 100 pounds ever made. This makes them a better investment and a possible collector's item.

2) Consider Steve Kayne's position that a blacksmith FORGES steel. The best tools and high stress parts are still specified to be FORGED no matter what the foundry folks say.

3) No matter how good a casting looks on the outside it could have a fist sized (or larger) lump of sand or dross in it somewhere. Critical castings are X-rayed for this reason and most of them end up being cut into and repaired to pass an X-ray exam.

I've had NEW Peddinghaus anvils in my shop twice. One was a 158 pound and the other a 275. Both had to be sold because I could not afford to have a NEW anvil in my shop that could be converted to cash. One went as a prize in the 2000 ABANA Junkyard Hammer contest and the other was raffled by CSI to pay an hosting/advertising client's bill. The second one is the one I photographed for the PeddinghausAnvils.com web site and is in our gallery. I dressed the horn to get it like that.

I have not been able to closely inspect a Refflinghaus anvil. Fit and finish wise the Peddinghaus could be better. Refflinghaus might be. But its NOT forged.

Neither one will make your work any better or worse. But if you have bad hammer control, do dumb things. . either anvil will get marked.

   - guru - Wednesday, 11/18/09 22:22:56 EST

Compressor fan blades for jet engines are cast, not forged.
   quenchcrack - Thursday, 11/19/09 06:34:10 EST

Stuck regulator & lube.... how about powdered graphite? I'm pretty sure that the stuff won't react to anything.

QC, on "How It's Made" they had a whole segment on fabbing of jet engine compressor fan blades. According to the footage, the little fins WERE forged, then put through a CNC process to refine tolerances, then x-rayed for imperfections. The episode was shot in '08.
   - Nippulini - Thursday, 11/19/09 08:38:15 EST

I thought a phd was a post hole digger.

Merl, My Auntie and Uncle had a big house as you describe in Cape Girardeau, MO. They heated with coal and the heat was sent upward to a cast iron 1 yard-square, "floor register," (a flat grille). The register was centrally located, so the heat reached two bedrooms, the bath, the kitchen, and the living room. The kitchen was huge and the cook stove was run by what Auntie called "coal oil."
   Frank Turley - Thursday, 11/19/09 09:30:54 EST

Compressor fan blades for Jet engines are both cast and forged, depending on where in the engine they are located. The front blades, while technically conpressor blades are really propellors as the air flow bypasses the combuster section mostly. The high temp turbine blades are mostly single crystal cast, and the smaller compressor blades are mostly forged fro Ti. The front fan blades are often composite. So both Quench and Nip are right.

The critical items like the shafts and the discs that the blades are mounte on are usually forged. Most now have hollow, air cooled shafts. Worked in the factory that forged shafts on upsetters and used to forge the discs and Bliscs.
   ptree - Thursday, 11/19/09 09:37:05 EST

As Ptree said, some are cast, some are forged. The point was to illustrate that not all castings have potato sized defects cast into them. I saw an $1100 Peddingzoo anvil that had the horn about 15 degrees out of alignment with the axis of the body. It was forged in two pieces then welded together and a weld is essentially a casting. I am not debating the general desireability of a forging over a casting but high quality castings often prove to be very reliable, cost effective alternatives to forging.
   quenchcrack - Thursday, 11/19/09 10:07:09 EST

Yes Frank, I have a buddy at work that has a heating system like that in his house and he wouldn't have anything else (although his runs on NG)Quiet and no moving parts to stir up the dust.
My great aunt and uncle lived in that house untill I was in my early 20s, although by then they would "go south " for the winter. For them, that mean they would close up the house and move to an appartment in Madison from December to the end of March.
   - merl - Thursday, 11/19/09 10:15:15 EST

Forged vs. Cast: The KEY to my statement is that critical parts are X-RAYed. On the mentioned aircraft parts every single one is X-rayed and the images shipped with the part certs. Allowed flaws are microscopic. My favorite micrometer company was put out of business because they phonied the x-rays (same film for every part) of aircraft parts. . . .

THEN, there are castings and there are castings. Modern auto part foundries use methods that almost absolutely prevent any significant inclusions. This is largely required due to focus on zero defects and all the machining, critical nature of the parts AND the fact they are NOT x-rayed. They do however use ultrasonic testing and other methods at the foundry to reject serious errors.

Anvils on the other hand are cast mostly in green sand or resin bonded sand. There are NO x-rays, no UT, no testing other than milling the face (on the best) or grinding the face. .

THEN there is foundry quality. I've seen imported power hammers with enough iron missing to make an anvil. Also open sand inclusions in cylinder bores! We have also had cases of fly-press nuts (an insert) that looked like old worm-wood from the sand inclusions. This was severe enough that the press locked up the first time it was operated. Any reputable shop would have scraped the part before it was finished. AND there is the little 15 pound Chinese ASO I have that the belt sanded face is ALMOST hiding the high degree of inclusions.

Consider the NY-Times article where man-hole covers made in India were being hand cast by naked bare foot men hand carrying ladles of iron down rows of floor molds (a sand pit) in the near dark. . . The scene looked like something from hell or a horror movie. The manager said they "never" had any serious injuries. I guess dead men don't tell tales. Do you think this same manager would lie about other things like the material content . . .

One of the biggest advantages of a forging is that the metal has been proven not to have severe flaws. If it survived forging then it cannot be but so bad. But with a casting you don't know unless there has been a lot of testing OR the quality is assured by superior methods.

Cast anvils by their very nature SHOULD be considerably cheaper than forged. However, many cast anvils are selling for as much as the forged.

LAST. . . Castings can also be a work of art for no more cost than an ugly industrial pattern with poor lines, obvious glue joints and poorly shaped features. The easiest part of making a casting is making the pattern. If the maker takes no pride in or puts no quality into the pattern OR does not know HOW to get a good pattern then what of the rest? The HARD expensive parts of the process have nothing to due with the pattern.

If you STUDY the lines of well made tools and look at much of the crap that is being made today it becomes easy to tell who cares and does not care about the product quality. Art and the labor of artists is CHEEP compared to committing to metal. AND even worse, there are good beautiful designs that could simply be copied. But when THAT is done poorly as well what we to think?

YES, some of the old anvils were pretty ugly. But they were FORGED and by hand using sledge hammers. It took a very well trained team in great physical condition to produce those works or art and they did so OVER and OVER each one by hand. To make a wood pattern is child's play in comparison. For it to be artless should be a crime.

Does a fine beautiful pattern mean the casting is good? No. But at least it shows that the maker cares.
   - guru - Thursday, 11/19/09 11:49:10 EST

I just wanted to put in a plug for ratholeforge.com cast anvils. I've been using a Rathole for about 3 years. It has nice lines and nice rebound. It is mounted in a box of sand. I believe that they are presently cast in Arizona where the face is Blanchard ground. When delivered to Wyoming, they are hand sand finished on face and horn. It's essentially a German pattern with an "American shaped horn." The cost would be pricey for some, but it is American made, American designed, and hand finished.

All of my other anvils are forged or partially forged, as are some of the Trentons, because I gathered them over the years. They were mostly found at farm auctions or through newspaper ads.

I like the idea of using a forged anvil, but face it, a lot of it is maudlin feelings. To a smith, the vision of forging such a large mass of iron "brings a little tear," because it is pretty much a thing of the past.
   Frank Turley - Thursday, 11/19/09 12:13:57 EST

I must admit I do a whole lot more forging on my 515# Mousehole that is a "cast" anvil than on my 410# Trenton that is a forged anvil... Mainly as I like the quiet.

   Thomas P - Thursday, 11/19/09 12:30:17 EST

I have a 100Kg (220 lb) Refflinghaus anvil as my main anvil, and I'd put it against any forged anvil any day. Especially as I got it in trade and didn't have to spend the cash they want for 'em these days!

The face is certainly hard, but not noticeably moreso than the face on my old 143 lb Peter Wright. The hardest anvil face I've got is on a 100lb Columbian, which is a cast anvil. It's also a very ugly anvil, with mismatched casting seams down the horn and body, and the hardness of the face has resulted in a complete absence of intact edges, rather like the damage often seen on Kohlswa anvils, another cast steel anvil known for being a bit on the hard side.

My only complaint with the Refflinghaus is the lack of a step, but that's easily fixed by putting a block in the hardy hole. I also occasionally miss the gentle swayback of the Peter Wright, but not enough to give up the long flat face and perfect edges on the Refflinghaus. The long square "horn" that makes up the heel of the Refflinghaus also comes in very handy for certain tasks that required a smaller bridge in the hardy hole on the PW or other London pattern anvils.

Refflinghaus is made in Germany where quality of workmanship is still valued, and it is not owned by an American firm more concerned with the short-term bottom line than with finish quality on such an outdated oddity as an anvil in the modern world, unlike Peddinghaus, now owned and mismanaged by the Ridgid group.
   Alan-L - Thursday, 11/19/09 13:06:54 EST

Thomas, I think you mean your 515 Fisher. . . All Mousehole anvils were forged. Unless you meant Rathole. . .

Yep, the Rathole anvils are a work of art. Very traditional and very clean except for the extras that make it a work of art. Like most American cast steel anvils the foundries do a great job as a matter of pride.
   - guru - Thursday, 11/19/09 13:18:43 EST

I would offer, having worked in and around commercial forge shops that made forgings of the size of anvils;
1. Forgings are as good or bad as the forging practice.
2. The material is as good or bad as the bar you start with.
3. Both the above apply to castings as well.

Given the choice in a critical application, say an aviation fitting to mount a landing gear or mount a wing spar, I would always choose a well made forging over a well made casting. In a high pressure valve or fitting, give me a well made forging every time.

In an anvil, I see no real advantage to a forged wrought iron body with a hammer welded top over a high quality cast anvil of good alloy.
I have a cast steel anvil and a high quality Trenton composite forged anvil. Both are very good anvils for their size, and oddly, the little 70# cast steel anvil is louder!
   ptree - Thursday, 11/19/09 13:19:47 EST

Yup I meant Fisher, things are crazy here today and as soon as I can escape this evening I get to pack for the Festival of the Cranes Demo.

Mousehole is one brand I have not owned---yet; but I'm slowing down my anvil hunting as I do have a nice set and there are so many others out there that need a decent anvil. I do covet the *big* NIMBA though...

   Thomas P - Thursday, 11/19/09 15:51:03 EST

Merl, I forgot to mention that the abult beverage is indeed still reserved for Quad State, the year of your choosing:) Next year should be excellent.
   ptree - Thursday, 11/19/09 17:48:37 EST

Ive got a question. Ive forged a bowie blade from a 70's coil spring and quenched it in oil. I then tempered it in the oven for a hour at 400 degrees, When it came out it was blue. Does this sound right. I think i need to normalize, reharden, and then try retempering at a lower heat to a straw color. What do you think?
   - davidsb - Thursday, 11/19/09 20:10:30 EST

I have a question about tempering. I just made a bowie from a 1970's coil spring. it was quenched in oil and i tried to temper it in the oven. I baked it for an hour on 400 degrees and it came out blue. Do i need to normalize, reharden, and then temper at a lower temperature? i didnt think that temperatures that low could turn the steel blue. What do you think?
   dsbarker - Thursday, 11/19/09 20:15:52 EST

David, As you have found out measurement devices are not all equal. Temperature is tricky. Hot air rises and the top of an oven or kiln can be hundreds of degrees hotter than the bottom OR where the temperature sensor is located. In broiler type ovens the radiant elements may heat an object much hotter than the air temperature.

While blue indicates a temperature of 500 to 600 degrees it may not be too soft for a blade. In many springs it is considered spring temper. As junk yard steel you need to test, test, test.

To re-heat treat you do not need to normalize again. But you do need to re-harden IF you want to try tempering again.

You will need to test your oven and perhaps use another temperature measurement system. You can test by using polished steel "coupons" and temper color to determine temperature and perhaps calibrate your oven whatever it is.

A tempering method I use is to heat a heavy steel plate to the desired temper color and then rest the part to be tempered on it. The trick is to get an even heat on the plate and not overshoot OR need to adjust down. Reduced heat cannot be detected without repolishing your heat sink.
   - guru - Thursday, 11/19/09 21:23:49 EST

Dave for a blade proberly from 5160 I would do two heats at 400...
   - arthur - Thursday, 11/19/09 22:02:11 EST

I never thought about anvils being x-rayed for bubbles or cracks, but can see where it would be necessary. Railroad rails are x-rayed for defects. If you see what looks like a small tolly car going down the tracks, look on the side, it will say Sperry Railcar. This railcar x-rays the rail and if a defect is spotted, it sprays a spot of yellow paint on the side of the rail.
   Mike T. - Thursday, 11/19/09 23:49:28 EST

Mike, my point is they don't x-ray, U.T. or penetrant test anvils.
   - guru - Friday, 11/20/09 01:06:53 EST

Non Destructive Testing is used on many products,But usually used when failur will be not acceptable in a way that justifies the cost. Railroad rails that fail lead to millions of dollars type accidents and deaths/injuries. Failed aircraft parts same thing. We Hydro tested every single valve we made. We UT tested every single friction welded flange on valves, we PT tested every part on every nuke valve. But then a valve that fails can lead to a Bophal type incident that injuries/kills thousands to 100K humans, and the high cost per item is justified period. That is why we spectro'ed EVERY single bar of metal for compliance to the specification, Hydro tested every single valve, Had tracability back to the mil for EVERY single forging we made, even on a 1/8" NPT pipe ell. Cause we bet the entire company on every single item we shipped.
Does an anvil maker bet the company on every produt shipped? depends on the size of the company. If an anvil has a sand inclusion or shrink crack in the center, will people die? probably not. Will a small shrink crack or sand inclusion in the heart of a cast anvil cause the anvil to fail? Probably not. Will a small area that failed to join in a hammer welded top plate fail, might, probably not.
In an anvil, probably not may be acceptable. In a Nuke or chemical valve, an aircraft attachment fitting "Probably not" is simply not acceptable.

Lets be realistic. 100 years ago a cast anvil was a low cost anvil, low quality anvil. Today, with precision investment casting being used to make aircraft grade parts, in exotic alloys, to extremely high standards, in sizes big enough to yeild the exterior casing of an aircraft jet engine, a cast anvil can be a vey high quality item. Or if made badly, a very bad quality product. But then a forging can be made just as badly.
I supect that a really nice, one piece anvil of 250 to 350# could be drop forged under a 25,000# hammer in closed dies. If the quantity was say 200 a year, the cost for the tooling could be paid by charging only $500 each. Thats for the dies. Throw in machining, heat treat, material, the cost of the hammer and maintenance and manpower, and say a little profit and one coul have nicely forged 250# anvils at 200 per year and they would only cost about $3000 each.
   ptree - Friday, 11/20/09 07:02:51 EST

We are a clay company and recently acquired a really cool clay working machine made by Crosley Manufacturing Company in Trenton NJ. I know they do not exist any more, but would you happen to know what happened to the patterns for the wear parts castings? Who, if anyone, bought the assets?
   Ann Engh - Friday, 11/20/09 09:39:45 EST

My point about castings is this. There are some really bad foundries AND worse quality control systems. In the two cases I mentioned of large sand inclusions in cylinder surfaces and power screw threads BOTH were situations that would have been obvious to the machinist and others and BOTH were made in employment situations where they dare not reject the part OR that all the parts were so bad that this was business as usual.

THEN there was the case of the Czech made anvil that broke in two (nearly at the middle vertically) and the seller would not replace it. . .

While quality control has advanced greatly in many cases in others it has regressed to the worst that has every existed in history. Much world trade is in poorly made items that are NEVER returned and complaints never reach OR have any affect on the maker.

If *I* sell you a defective product and you come to me about it you will get immediate satisfaction in the way of a replacement or refund. I cannot afford NOT to do so. But this is not the case globally.
   - guru - Friday, 11/20/09 11:45:34 EST

Guru, we need to separte bad busness practices among, in this case, foundry business and bad manufacturing methods. I am sure there are many unscrupulous forging houses too. I worked for 3 foundries right out of school. Two of them were pretty good, one was on the level of the Chinese ASO makers. None are in business today.
   quenchcrack - Friday, 11/20/09 14:39:55 EST

You can't make generalities about local suppliers OR global suppliers. Anywhere you can get good support and bad support, no country has a monopoly on poor service. My induction forges are made in China and I've had almost ZERO problems, but they have airmailed me parts for free when needed.
   - grant - Friday, 11/20/09 15:09:15 EST

I have been working as a plant metallurgist in a forge shop making open die forgings up to 60,000 lbs for the last six and 1/2 years and I have seen the same defects Jock described in castings in forgings. Sand inclusions, flux inclusions and refractory are all present to some degree in forgings since ALL FORGINGS START FROM CASTINGS. If proper forge techinique is not used gross ingot piping (shrinkage cavities) will not be consolidated. The use of a particular process is no gaurantee of qaulity or performance unless said process is done using best practices and appropriate inspection.

From a performance point of view, it makes no differnce if and anvil is cast or forged. Critical variables are primarily heat treatment, possibily alloy selection and finish. As a user, the only one you can change is the finish. Personally, I find that design and appearance mean more to me that forged over cast. The specific question was between two reputable German manufacturers. Both have long histories in the anvil making buisness and both have reputations to protect. That being the case, I don't think that you have to fear low quality/poor craftsman ship in either one. The decision should come down to the differnce in hardness of the two anvils, and the design features of each. Since that is a personal preference matter, I don't think you can say "this is better than that" but only "I like this one more than that".

By the way, the Pendinghouse is not the only forged anvil be produced today. There is also one being made in Turkey and being sold by Old World Anvils.

   Patrick Nowak - Friday, 11/20/09 17:11:47 EST

Patrick, well said.
   ptree - Friday, 11/20/09 17:50:10 EST

Just for the record, Nimba Anvils are CAST.
   quenchcrack - Saturday, 11/21/09 09:42:42 EST

just got a new anvil about 150 lbs only marking is the word mline any one ever heard of this brand name
   - jessee - Saturday, 11/21/09 19:04:06 EST

All steel may start as cast material but many (probably most except very large) forgings are made from bar and plate that has been rolled and/or forged to condition it prior to being cut into billets for forging to final shape, just as the smith doing hand forging. Most of the problems of being "a casting" have already been treated. The forging then further refining the grain direction and structure.

I looked up one brand of Turkish anvil and the manufacturers web site used the term cast and forged interchangeably in numerous paragraphs. I received no response to a letter inquiring which process was actually used.

Now, both issues may have to do with language and translations BUT the responsibility of publishing accurate specifications is up to the manufacturer. While many businessmen do not consider their web presence to be important, accuracy there is an issue of overall quality. Like putting a microscopic bit of research and art into an anvil design. Inaccurate specs, lack of basic art, what else is lacking?
   - guru - Saturday, 11/21/09 21:33:51 EST

Anvil ID -mline : Jessee, never heard of this one. Are you sure its not Milne? At least that is a name.

Are the letters raised, broad and sunken, or thin and carved or stamped into the surface? Raised letters indicate a casting in most cases. But they may also be recessed. Recessed in a block can indicate forged or cast but this is rare.

In cast anvils there are many produced for farrier schools that were made in low enough production that most are not known or in lists of anvil brands.

If the the lettering is faint and stamped then it is often easy to missread. This is especially true of old anvils that have rusted, been painted over rust, have dirt in the lettering. When letters are faint or missing the eye will make up the missing parts like seeing the lines between stars thus creating constellations.

Email me a photo if you have one or more and we may be able to help more.

   - guru - Saturday, 11/21/09 21:44:26 EST

Jessee, Sounds like it must be YOURS.
   Carver Jake - Saturday, 11/21/09 22:09:32 EST

Jock, I know a few pattern makers that would have you up on the statement that the pattern is the easiest part of making a casting....

Personally I dont think it matters a jot whether an anvil is cast or forged, the devils in the detail (ie the heat treat), and as others have mentioned the rest is down to preference.

Country of origin has no relation on quality. Folks manufacture what you pay them to manufacture.

most of our anvil obsession is just vanity,. look at the work Japanese smiths have achieved, or germanic smiths patternwelding beautiful sword blades 1500 years ago, its not what youve got, its how you use it :)!

me, well im afraid ive added another to my 'collection' a 500lb+ vaughns cast steel lump, in pristene condition (well, its got a rusty face), the cost at todays exchange rates about $160usd ! I 'sniffed' it out, and after about a year convinced the firm to let me have it! Now im just a bad workman, and am running out of tools to blame it on :D, the UK is definatly 'anvil rich!'
   - John n - Sunday, 11/22/09 05:17:47 EST

All steel starts as castings, and good rolling practice will indeed TEND to close up shrink cracks and pipes, but sand, and other debris not much help. The root of good parts from steel is all in the care taken in the process, not the process itself. I have seen steel bar of 5/8" od, that had been under who knows how many reductions, that had a pipe down the center, that would pass 1000 psi nitrogen. Made in the US, by a reputable brand.
I have seen more laps in forgings than anyone on the site has sen anvils:) Seen forge tears from bad practice. Seen huge numbers of underfilled forgings that needed weld repair. All in a super careful shop, using good practice. The DIFFERENCE, is that we were careful, and inspected and rejected the bad parts. The laps were seen as dark lines in the still hot forgings and pitched in the scrap. The forge tears were usually found at the machining, but also at test, and rejected, and the part scrapped.
We made the absolute best forged final product money could buy. When we shipped it, we bet the company on it. The buyers did not see the rejects and scrap.
So yes absolutly forged is better than cast. Or not.
   ptree - Sunday, 11/22/09 08:10:27 EST

Patterns and Molds: I've made patterns and molds for ceramics, plastics and metal including permanent metal molds for precision Zamak parts and loose patterns for swage blocks including cores. Some of the ceramic and plastic molds were five or six piece and the iron molds for Zamak were equally complicated. In every case getting good castings from either our shop or commercial foundries was the hard part. I've also designed (and built) machinery with castings in the four and five ton range.

On the other hand, I've been around this my entire life and some of my earliest memories are of my father making ceramic molds and castings. But I know other metalworkers that when they turn their hand to wood or plastic consider it a break because it is so easy by comparison to metal.

For me the easiest patterns to make were the swage blocks. A good loose pattern without cores takes less than a day and a with cores another day or two depending on how many core boxes needed making. An anvil pattern is dead easy including boarding and the core box. That includes a good sculptural shape without kinks and ugly lines (pick ANY shape in our anvil gallery). To add high art decoration like icanthus leaves or a bas-relief scene add another day or two if the art is already designed.

Now. . one of our regulars had patterns made for a draftless swage block. Now THAT is a job. A pattern that does not reflect the part in the least and four mold boxes for loose pieces. I suspect quite a few industrial blocks may have been made this way.

Making wood patterns IS easy. Making metal patterns slightly harder and much more time consuming when cast due to the double shrink and refinishing the metal pattern. Machining them from solid is similar to die sinking and mostly time consuming (thus expensive) but not technically difficult.

Complex shaped patterns for hollow parts like automotive intake manifolds and blocks is tough. It is also work that is being taken away from pattern makers and going to scanning LASER technology and foam investment where there are no cores, just a hollow styrofoam investment.

It can be difficult making patterns for designers that do not have a clue what can be cast and not. It is more difficult when the designer will not compromise on impossible features and yet even more complicated when the foundry wants to dictate details rather than providing the service that is their business.

My obsession is with those that are too lazy or too artless to do a good job when it takes no more effort to do the job right or with some art.
   - guru - Sunday, 11/22/09 09:15:01 EST

An ounce of prevention is worth a pound of inspection. A product will never cost less to produce than when it is made right the first time! ISO 9001 certification is no guarantee of quality; is is a guarantee that all defects will be documented. Why do we never have time to do it right the first time but always have time to do it over? Yeah, I have heard them all and it always comes down to the will of the managment to either make a quality product or not.
   quenchcrack - Sunday, 11/22/09 10:15:27 EST

Guru and friends: Is it Ok to use brass screws to join mild steel? the steel rod is gonna be spray painted and i need the screws for decor.. but what about galvanic corrosion? I don't want my project to fall apart... can i use something else?
thanks in advance
   - Kia - Sunday, 11/22/09 11:43:02 EST


What is the general significance of the 50:1 rule for anvil weight/hammer weight?

For instance, will using a 4 pound hammer to forge on a 150 pound (forged) anvil simply diminish the efficiency of the blows or is there some reality based concern about damaging the anvil?
   - deloid - Sunday, 11/22/09 15:15:34 EST

Kia, Brass and steel are about as bad a combination as you can get. They will do OK indoors if sealed but should not be used outdoors.

For outdoor use you can go two ways. All brass with paint and polished highlights OR all steel with brass paint highlights.

   - guru - Sunday, 11/22/09 15:35:03 EST

Forge welding
I spent the weekend over the forge not making a project, but just trying to do two things. Play with different fires, and forge weld. I have read the two iforge tutorials multiple times, and other descriptiions of welding. I played with spring steel and hot rolled steel.

I assume when you destructive test a forge weld it should be as good as an electical weld, correct? The closest I came to a faggot weld in the hot rolled steel was one side looked good, the other side almost good. I cut it in half and I could not see a parting line. When I hit it a few times with a cold chisel it appeared to break .015 of an inch away from the joint.

Second question. Clinkers are black and glassy when cool correct? When I cleaned out my forge I found a couple of round bubbly objects in the bottom. They were magnetic. I use charcoal. If they were orginally nails, that melted, would that effect my welds?

Thank you for your help.
   Milton - Sunday, 11/22/09 16:01:59 EST

50:1 anvil ratio This is my rule. I made it up.

It is based on common shop usage and anvil efficiency ratios.

Anvil efficiency is 40% at 10:1 and 70% at 20:1. This is suitable for machines but when its your personal physical energy that is being wasted then efficiency is VERY important. At 50:1 efficiency is 96% to 97%.

In general use you find farriers using 100 pound anvils for portability and roughly 2 pound hammers for forging. That is a 50:1 ratio.

In the general shop the recommendation was a 200 pound anvil and up to a 4 pound hammer. Again 50:1. This is from centuries of shop and field practice.

In the heavy forge shop where sledges are used a lot anvils of 300 to 500 pounds are common with sledges of 6 to 10 pounds. Again roughly 50:1.

So, it doesn't matter if you are using a little 20 pound bench anvil and a 6oz hammer or a 500 pound anvil and a 10 pound sledge. Shop practice and efficiency ratios say 50:1 is the right ratio.

However, smiths working at over the 50:1 rule say they can tell the difference, get more work done and are less tired at the end of the day.

Less is inefficient (wasting your energy) more doesn't hurt.
   - guru - Sunday, 11/22/09 18:13:46 EST

Clinkers: Charcoal generally does not produce clinkers. However, some of the ash scale and flux will make "clinker". In coal the clinker varies in shape and color. Some is silver grey and some is brown depending on what the mineral content of the coal is. Coal ash can be dry and dusty like charcoal of form heavy clinker. Generally it is considered good when low ash coal forms clinker.
   - guru - Sunday, 11/22/09 18:31:06 EST

Welding issues: A forge weld should be as strong as the base metal. However, in practice it is not always so. Weld strength is strictly a matter of cleanliness and steel condition.

If steel is held too long at welding heat in an ozidizing fire the steel becomes decarburized (loses carbon). The low carbon weld zone is weaker than the surrounding metal. For this reason forge welds in wrought iron are generally as strong as the base metal but not so much in steel.

Any scale or dross in the weld zone is not weld therefore weakens the weld. Keeping this out is an art. It takes technique and practice. Overheating the metal is the primary fault. Having the proper fire is critical to making the best forge weld.
   - guru - Sunday, 11/22/09 19:15:27 EST

Does the mineral content of coal vary accordingly to what layer of earth it is found in? Ive bought coal 2 different times from the same place, the first time it burned very hot and with alot of clinker. The second time it burned about the same but with much less clinker. Its been awhile since the first time (Been using charcoal) but I figured it could be that the mine is further down now. I dont really know much about how coal forms but couldnt help but guess, What do you think? What causes steel to crack at the end of a peice when you are forging it down? This has happened a few times even though i quit hammering at a low orange. Thanks!
   - Jacob Lockhart - Monday, 11/23/09 11:45:19 EST

I found a page concerning the peddinghaus anvil that had some more info on my previous questions. http://www.piehtoolco.com/contents/en-us/d853.html and i learned that there is 2 different brands of peddinghaus anvils that are both drop forged. Well thats how the site nakes it look.
   - Jacob Lockhart - Monday, 11/23/09 13:53:24 EST

Coal Variations are INFINITE. It is a sedimentary product formed at the bottom of great swamps that were then submerged under the oceans and deep sediments that compressed the organic matter into solid coal. As a freshwater swamp there would be floods and disturbances (such as volcanic erruptions) that deposited layers of clay silt or volcanic ash into the coal beds.

While many seams have a sharp demarcation between coal and rock other places fade from one to the other. Some coal, while black and coal like is so low quality that it will not burn at all. In West Virginia they call this "red-dog" and pave roads with it.

   - guru - Monday, 11/23/09 16:50:09 EST

Jacob, Yes, there are TWO Peddinghaus anvil brands. There is also a Peddinghaus machinery company that is unrelated to the other two and I would bet other companies with the same family name. . . The small Peddinghaus Tool Company anvils are pretty ugly and the largest is 165 pounds. They are good anvils but the small foot print and light base mean they need to be bolted down for heavy work. Unless shipping is an issue Blacksmiths Depot prices are quite a bit less.
   - guru - Monday, 11/23/09 17:06:30 EST

Two questions :)
The coal is in the forge, the center is the hot spot. Then
the coal next to the hot spot starts turning into coke. As the forging progresses the coke is then fed to the center ?
How should the tuyer ( bad spelling ) be positioned for maximum effect ? Lets say the forge is so many square feet wide and long, how big should the hot spot be ? Where you want to concetrate air flow.

Also, band saw blades are said to be L6, what would the steel be in a regular carpenters hand saw. If it is the same steel used in old cross cut saws, it would be good steel. I used to have a knife made from an old cross cut saw blade with an antler handle, thin and sharp. Also, the saw blade could be folded and welded, for a thicker blade ?
   Mike T. - Monday, 11/23/09 21:35:03 EST

Blade steel ALL Junk Yard Steel rules apply. Only SOME bandsaw blades are L6.

Firepot placement in a forge depends on the forge size and shape. In round or square forges it is almost always in the center. In rectangular forges it is usually equal distant from the sides and one end. The extra space is for coal reserve and supporting long work. Being close to one end also provides a close wall for the vent. However, you COULD make a rectangular forge with the firepot centered and the vent at the back. But the traditional method is toward one end.

The tuyere is centered in the firepot if a bottom blast. If a side blast then it is spaced off the bottom of metal forges to prevent burn out and near the side wall due to cooling limitations.

Yes, all the coal and coke move toward the center of the fire pot. On rectangular forges you need to pile coal up behind the firepot higher than the front so there is coal to feed. Fire maintenance is a continuous process that become second nature after a while. Then you don't even remember doing it.
   - guru - Monday, 11/23/09 22:14:47 EST

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