WELCOME to the anvilfire Guru's Den - V. 3.3

THIS is a forum for questions and answers about blacksmithing and general metalworking. Ask the Guru any reasonable question and he or one of his helpers will answer your question, find someone that can, OR research the question for you.

This is an archive of posts from July 1 - 7, 2008 on the Guru's Den
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Passive Systems with low powered assist such as the fan you speak off should be part of every home. Other more sophisticated systems should be available but lack of interest in conservation has thwarted their economic production. In the 1970's the research was conclusive on the cost savings of super insulation but we ignored it and went the cheap route of super tight and thus unhealthy buildings and homes. You gain as much or more with tight windows and doors as with super insulation.

Smart low impact active systems could greatly improve building efficiency. Automatic shutters, vents and fans coupled to a smart system that reacts in advance of daily and seasonal changes. Most systems turn on fans or equipment after environmental changes are detected. We can do better, and should.

   - guru - Tuesday, 06/30/09 22:47:41 EDT


If you fill your shop with enough old tools, machine and/or hand, it can add a lot of thermal mass due to the large amount of steel and cast iron, or at least it does in Rube Miller’s shop. I was there about two weeks ago, and despite the summer heat, it was quite cool! I mentioned this to him, and he said it stays that way till September, (gradually warming). I was considering why this was, and reached over to touch a lathe – the steel was cold! The shop is partially below grade with a second level above, but, really, he’s got so much old heavy-duty machines that the inside area is probably at least 25 per-cent solid iron & steel. The outside is surrounded with more: Steam traction engines, steam shovel, old saws, and anything else you could imagine. I would think that all this keeps it warm in early winter, too. I can’t estimate the size of this shop because I can’t see the walls, or indication thereof. nrn
   Dave Leppo - Wednesday, 07/01/09 07:20:01 EDT

My passive solar, super insulated house has a semi tight air infiltration system. The windows and doors seal tight. The entrance doors have refrigerator type magnetic seals. The windows are awning type that crank closed and compress gaskets. A sliding double hung window will never stay tight as there is no compression after the seals take a set.
The swinging atrium door at the main entrance is wood and so plain gaskets, but it has a steel storm door.
When I was building the house many told me I was crazy to install a poly vapor barrier. Was not well know then. The vapor barrier is NOT sealed at every joint and therefore allows some little infiltration air, but this avoided sick house issues.
I also used foam insulation panels as sheeting, and these had aluminum reflective facings on both sides to stop radiation of heat. The tight fit of these panels also helped with infiltration of air. The corners of the house do not have plywood sheeting, as that is where the need is most of insulation (two cold walls). My system uses inletted 1 x 4 boards on diagonal in the 2 x 6 studs(then also un-heard of).
The insulation levels and vapor barrier led many to believe I would have condensation in the insulation especially in the roof. I had done the home work and found that the level of roof venting above the insulation had been increased by the Dept. of Ag, the folks that write that stuff for the feds by 600%, and was under consideration for another increase. So I installed roof venting at about 1000% of what was then standard. After I had reason to look into the roof space post tree damage, I saw the beginnings of some mold on the roof deck and added another 300%. I had reason to look again about 4 years after that and all good.
My system depends on a $20 in/out therometer, and a human to open windows and turn on the fan or reverse. Works.
I do supplament the heat in the winter, and am maintaining 72F in the day, 65F night time on 3000 sq feet, and my cost for the mostly bought fuel, total is about $300 a year. That total cost includes gas to haul. I do live in a wood rich environment. I do use an outdoor woodburner. It is an EPA stage II approved unit, that makes almost no smoke or particulate compared to the early models that the Guru so hates. Uses about 40% less wood as well, as it reburns the smoke(wasted energy) to get to the low emission levels.
There are many ways to save energy in a house, especially when you build from scratch. Retrofits in older, low insulation level, poor window type houses is much harder.
Retrofit active solar is not ever going to pay in about 90% of this country. Passive solar pretty much only works when built in from scratch.
   ptree - Wednesday, 07/01/09 07:37:09 EDT

More on the American Wrought anvil... after getting it home last night I immediately placed it on a stump and broke out the wire brush wheel. The trademark is perfect, I will fill it in with white paint for the pictures. The foot mark reads 573. After brushing the dirt and rust off the top, I found the face to be severely pitted. :( No problem, I can dress it up but I know it will be a long arduous job.

Hey Ptree, see if you can jimmy up a solar powered forge.
   - Nippulini - Wednesday, 07/01/09 08:30:08 EDT

The sad part of the insulation issues is that it was all proven and recommended over 30 years ago and they are still making inefficient poorly built houses. When you buy a half million dollar house today you are getting 1960's construction methods using the cheapest 1990's materials. They are big and poorly built. Then the folks that can least afford it, those that buy modular homes are getting even less. Walls and ceilings with only 2-3/4" space for insulation. . .

Imagine the total savings if every home built in the last 30 years had been properly built to at least the 10 year pay-back insulation levels. . . Owners would be better off, the country would be better off.
   - guru - Wednesday, 07/01/09 09:41:43 EDT

One problem is that people have gotten away from regular "chores" once a standard part of living. So houses are designed to be "maintenance free" and then have catastrophically system failures.

I have no problem opening windows at night and closing them and the blinds in the morning and using external cooling. My wife prefers to run the swamp cooler 24x7 to doing a 5 minute chore twice a day.

Our passive solar house is great in the wintertime, we have a woodstove for back up and burn way too much wood as we enjoy watching the fire through the ceramic window on the woodstove. During a cold winter we will go through about US$150 of wood---so that's our total heat cost for a winter, the rest of it being free thermonuclear energy. and yes our outside walls are 2x6 to allow for greater insulation.

   Thomas P - Wednesday, 07/01/09 11:20:44 EDT

One side benefit of the heavier insulation in the new house (after 30 years in the 1924 plaster and lather/clapboard/uninsulated walled old farmhouse) is just how quiet things are. I mean, it's quiet in the country; but when you're buttoned up inside you can't hear the naval guns testing at Dahlgren (at least the lighter ones); the helicopter flyovers, the drag races, the over-speakered local kids' cars, the drag races, the neighbor's signal cannon, hunters, etc. About the only sound that routinely penetrates is thunder!

Me, I like to be outside, and try to keep the windows open well into summer. The wif, however, loves her HVAC, and uses the dog-pant method to determmine when to put it on. ("When the dog starts panting, it's too hot! You wouldn't want the dog to suffer; would you?")

Sunny and warm on the banks of the Potomac; possible T-storms this afternoon. I'm off to visit the Smithsonian Folklife Festival on the Mall ( http://www.festival.si.edu/ ) for my lunchtime trip. I'm sure the Welsh will have a blacksmith there.
   Bruce Blackistone (Atli) - Wednesday, 07/01/09 11:31:33 EDT

Bruce, I too noticed the great reduction is noise level when buttoned up. In the summer, when buttoned up, we can hear thunder, but muted. Occasionally in a real clousd burst, we acn hear the rain on the roof through all that insulation, but not often.
Back when the Ky AFNG flew Rf-4's, they made approachs over our house at about 500', with the boundary air on and lots of throttle. We could hear them a bit when buttoned up, extremely well when open!
They fly C-130's now, and when buttoned up no notice, open I know they are going by, but not bad.
   ptree - Wednesday, 07/01/09 13:12:28 EDT

Folklife Festival Report:

It took me all of 60 seconds to find the blacksmith setup in the "Wales" area; she's Iona McLaggan from Bridgend in S. Wales. Very nice to talk to; very patient with the touristas, and a very sure hand. We had a delightful conversation, part of which went something like: "Anvilfire eh? Which one are you?" ;-)

I'll try to catch her tomorrow before I shove-off for Baltimore, and chat some more. I've taken some nice pictures, but I'm using film, so it may be a while.

The rest of the arts and crafts and folkways in the Welsh part of the festival is very nice; with boat building, slating, stone carving, traditional building techniques, cooking, bookbinding, animation, and a slew of other items of interest. Alas I had no time for the music (yet), in any of the three sections of the festival.

   Bruce Blackistone (Atli) - Wednesday, 07/01/09 14:09:00 EDT

Folklife Festival Report:

It took me all of 60 seconds to find the blacksmith setup in the "Wales" area; she's Iona McLaggan from Bridgend in S. Wales. Very nice to talk to; very patient with the touristas, and a very sure hand. We had a delightful conversation, part of which went something like: "Anvilfire eh? Which one are you?" ;-)

I'll try to catch her tomorrow before I shove-off for Baltimore, and chat some more. I've taken some nice pictures, but I'm using film, so it may be a while.

The rest of the arts and crafts and folkways in the Welsh part of the festival is very nice; with boat building, slating, stone carving, traditional building techniques, cooking, bookbinding, animation, and a slew of other items of interest. Alas I had no time for the music (yet), in any of the three sections of the festival.

   Bruce Blackistone (Atli) - Wednesday, 07/01/09 14:12:20 EDT

Folklife festival Report contd.

Iona's web site: http://www.ionamclaggan.co.uk/
   Bruce Blackistone (Atli) - Wednesday, 07/01/09 14:13:05 EDT

Nippulini: You have one of the earliest anvils made by Hay-Budden. According to AIA, likely 1892. There is a photograph of one on page 290 of AIA and it also appears to have a three-digit serial number. An ad for the brand name under it dates to 1894-95.
   Ken Scharabok - Thursday, 07/02/09 00:10:58 EDT

Nippulini, I know you jest about a solar forge, but I have been toying with the idea myself. I have access to an old satellite dish about 10 feet in diameter, and if I line it with reflective material.....look out! Some of the info I have indicates possible temps as high as 3000F at the focal point. Not very practical, I admit, but fun!
   Dave F - Thursday, 07/02/09 08:05:59 EDT

I just looked at your brake drum forge plan and will use some thoughts from that. I add the following: For air, I usually use vacuum cleaners modified as required and regulated a dimmer switch which I have built inito an extension box. Squirrel cage blowers never seem to exert enough pressure to do the job. Also, using 2" plumbing fixtures, a flange on a short nipple can be tack welded to a section of a discarded 20lb propane tank and remain lighter and readily removable and replacable...naturally not to be attempted by anyone not absolutely sure of the safety requirements of undertaking such a project. Scrounging mechanical parts can lead one to small gears that can be attached to a rod that can pass through the 3 way fitting and make a most adequate grate / clinker breaker. I can offer more details if required.
   DPK - Thursday, 07/02/09 08:18:52 EDT

Living in NM I looked hard into building a solar forge based on an old Mother Earth News array made from 1' sq mirror tiles that even had a sun following circuit.

Unfortunately the very common very high winds soon convinced me that it would not last long enough to be useful. I was going to feed the primary focus through a slot in a steel box full of refractory to make the forge part.

   Thomas P - Thursday, 07/02/09 10:37:05 EDT

I just acquired an assortment of steel bars and large flats from an old logging HQ site. Most of it has sat out in the weather for 50+ years and is a bit pitted and rusted on the surface. I've cut the ends off some of the 2" and 3" bars with a band saw and the steel below the surface is very nice. How much do I need to clear the surface rust off before heating some of this stuff up and shaping it? I've been told that most of the rust will burn/flake off during heating and what doesn't, won't do any harm. It sounds good, but I'm not sure I trust that advise.
   Ross - Thursday, 07/02/09 12:42:38 EDT

Ross, The advise you were given is correct. However, it depends on the final result you desire and how much you forge the steel. IF the steel is heavily worked you will never know there was any corrosion. If lightly worked or not worked all over the roughness will still show. Many smiths store old rusted steel for jobs were they need to match old materials OR are looking for a rustic surface.
   - guru - Thursday, 07/02/09 13:33:23 EDT

Ross; I had a job once where I wanted to be sure that the customer and I were using the same language to mean the same things. So I forged a minature of the item and as it was meant to be discarded I used the worst piece of steel I had to hand---had been drug out of a manure pile I believe.

It was *EXACTLY* what she wanted terribly pitted surface, rough forged, etc. Sigh.

"The customer's money is always green"

   Thomas P - Thursday, 07/02/09 14:50:24 EDT

RE: Solar Forge--Somewhere back in my befuddled younger years I read a frensel (?) lens [the flat lens you often see used as book page magnifiers] would concentrate the sun's rays enough to enamel metal (i.e., fired enamel). Recently got one out of a scrap pile, need welding goggles to see what I am doing. Sets paper on fire easy enough.
   - David Hughes - Thursday, 07/02/09 15:37:24 EDT

RE: Solar forge--Back in my younger wicked days I read that a frensel (?) lens [the flat lens that you often see as book page magnifiers] would concentrate the sun's rays enough to fire enamal on metal. Recently pulled one out of a scrap pile, need welding goggles to see what you are doing, sets paper on fire easily enough.
   - David Hughes - Thursday, 07/02/09 15:40:47 EDT

Sorry about double post, the first time it acted like it had indigestion and barfed it out into the ether. Redone, and then both showed up
   - David Hughes - Thursday, 07/02/09 15:44:46 EDT

Fresnel lense: I got one from Edmund Scientific when I was a kid, never used it, but can't find it. I DID find "Fun With Fresnel Lenses" copyright 1971, a little project book I got with it for an additional $.75.
   - Dave Boyer - Thursday, 07/02/09 20:22:54 EDT

Somewhere in the dim memories of my youth I remember a photo in an old general science book. It was of a French installation of mirrors used to melt a high temperature metal (platinum or tungsten). It was built in a natural amphitheater and had some sort of mechanical tracking device for the mirrors.
   - guru - Thursday, 07/02/09 21:18:19 EDT

Rusty Steel: Thanks for expanding my perspective on this old steel. It sounds like, rather than ensuring the pitted surface is hidden and kept from having any effect on the substrate metal, it may be regarded and used as an attribute… something to be preserved as is and stored for the right project.
The machinist in me wants to trim all of the ‘bark’ off every piece of stock. You’ve given the artist’s imagination something to play with.

I appreciate it.
   Ross - Thursday, 07/02/09 21:55:21 EDT

Ross, On much blacksmith work a consistent finish is where the difficulty lies. Even the finest forged work has a texture difficult to match. Good hot roll is sufficient on some work. On others it requires forging all over. Cold finished steel is only suitable if the work is to be finished all over.

On flat work where a heated surface is to be matched rusted steel is good. Smiths also create purposely textured steel using various methods. Heating and forging scale into the surface makes a smooth even finish. Heating then breaking up the scale then heating again to remelt the scale and create more in between. This is then cleaned by wire brushing. The results can be varied by the number of steps, how hot, hammering between heats.

For heavy texturing on a significant amount of work a power hammer is used. This can be done with plain or textured dies of various types.

Lots of choices.
   - guru - Friday, 07/03/09 00:22:11 EDT

Thomas, you used "rot" iron for a prototype?
   JimG - Friday, 07/03/09 09:30:02 EDT

One of my friends at work gave me a bunch of cabinet hardware consisting of cast fittings. I assume that they are "pot metal" and primarily zinc. Now, the question that has occurred to me is if I can use them, in scrap pieces, for brass casting to replace some of the zinc that burns off; or is the metal too mongrel of a mix?
   Bruce Blackistone (Atli) - Friday, 07/03/09 21:54:03 EDT


I looked up Zamak, which I think is a common casting alloy (though I could be wrong). It's 4% aluminum. That's not *necessarily* bad in a copper ally -- aluminum bronze has a higher aluminum content. But aluminum's probably not an intended constitutent of your brass ally, and I'd be a little worried about getting unexpected results if it were added.
   Mike BR - Friday, 07/03/09 22:29:20 EDT


The problem is, they're "primarily zinc", not pure zinc. They also add antimony to that stuff to make it fill the mold better, and other stuff that you may not want in your brass castings. I've never had any real issues with zinc depletion in casting brass until you've melted the same stuff more than once or twice.
   vicopper - Saturday, 07/04/09 08:03:45 EDT

Jim it was *not* real wrought iron just highly corroded mild steel. Turns out that that person wanted my *worst* work and not my best; almost ashamed to put my maek on that project.

   Thomas Powers - Saturday, 07/04/09 16:46:45 EDT


Never be ashamed to put your mark on work like that - I put your mark on all my bad stuff. (grin)
   vicopper - Saturday, 07/04/09 17:08:54 EDT

Hi guys- I was just poking around on youtube and ran across this old film.
pretty cool. It's in Austrian (I think) but interesting none the less. http://www.youtube.com/watch?v=KM6cy-9DWK0&feature=related
Check out the big hammer, and how much fun the smiths are having.
   Judson Yaggy - Saturday, 07/04/09 19:01:06 EDT

The big hammer is a 500# or more mechaincal. Could not see enough to identify it but it was not familiar. Hits a lot harder than an equivalent air hammer. You have to move really quick.

Last weekend I visited my friend Josh Greenwood. He is making a gate with a 1-1/2" x 2" frame. We helped upset the 2x2 stock into 3x3 ends which were then punched on a 500 pound Chambersburg. Working big stock is a lot different than small. The 80 pound pieces were upset by lifting about two feet and dropping on an anvil set in the ground. HARD work. .
   - guru - Saturday, 07/04/09 20:14:33 EDT

My first thought was that it looked like a bigger version of the Allinder (sp?) that was featured in the Hammer's Blow a while back. Of course, it's possible that the Austrians or Germans have the ability to make their own hammers ;).
   Judson Yaggy - Saturday, 07/04/09 20:35:19 EDT

I read that argon cuts down on oxidation and scale. Propane set 3-4 pounds on regulator. Using a blower. How much argon should go in the mix. Your thoughts on this.

   Mike T. - Saturday, 07/04/09 21:48:10 EDT

Any reference as to how to approach the making of a replacement coil gong for antique clocks? Size/diameter doesn't matter...I'm more curious about type of steel and jig.
   - albert - Saturday, 07/04/09 21:52:06 EDT

Any reference as to how to approach the making of a replacement coil gong for antique clocks? Size/diameter doesn't matter...I'm more curious about type of steel and jig.
   deloid - Saturday, 07/04/09 21:52:39 EDT

Argon: Mike, I've never head of using inert gas with a propane forge. It is common in electric furnaces. The argon would thin the oxygen level if too much (or possibly enough to make a difference) was used. You should go back to the original source on this matter.
   - guru - Saturday, 07/04/09 22:15:05 EDT

Spiral Gongs: Deloid, To a degree the harder the steel the higher the pitch. However, these are generally not hardened. Good work hardened cold drawn mild steel should work. Rules on gongs are fairly simple. The longer the bar the lower the pitch. The larger the bar diameter in proportion to length the higher the pitch. It is simple proportions.

I would wind the coil on a lathe using a pin and two plates. A washer at the center would clamp the center looparound the pin and the wire would be wound as needed. Spring back would open the coils but if not enough then manually opening the spring is easy.

Tuning of this type thing is pretty much trial and error but I would keep track of the proportions.
   - guru - Saturday, 07/04/09 22:50:27 EDT

You missed the joke Thomas, I figured since it was dug out of the manure pile it had to be "rot" iron (insert gratuitous smiley face here). Once upon a time I mentioned to a potter that when I used to do more wood work I would get rid of my mistakes in the wood stove. But now I throw my goofs in the compost heap. The potter says to me, "Jim, it doesn't work that way" to which I replied, "what? you never heard of "rot" iron?"
   JimG - Saturday, 07/04/09 22:55:33 EDT

hello, my name is Matt, and I have a question about forge welding, its been over a year since I started trying to weld. I follow every technique possible, and I have taken a class, and still I cannot achieve a proper weld, I even visited Colonial Williamsburg, and they obliged to show be a simple weld, but when I do it myself I fell again. if there is any advice you can give me I would appreciate it.
Thank You
   Matt - Saturday, 07/04/09 22:56:20 EDT

When welding iron, it changes color.

Aluminum does not seem to change color when it melts (at 600 degrees).

Why does iron change color and not aluminum?

At what temperature would aluminum become "red hot"? Or any other color? Do all metals eventually become "red hot"?

Thanx so very much for your help.
   mike - Saturday, 07/04/09 23:12:35 EDT

Matt, Get to the anvil quickly. Do dry-runs repeatedly until getting to the anvil is second nature. Don't look at the pieces when you get to a welding heat; look at the anvil. That's where you're going. When the pieces are approaching the anvil, THEN you can look at them. If you look at the pieces right out of the fire, you may get mesmerized by the "sparkler effect," and that slows you down. If it's a fagot weld, have the hammer in your hand already, while the tongs are in the other hand. If it's a lap weld, have the hammer by the heel of the anvil. Have a clean fire, if it's coal. Put borax on at a bright heat so that it melts and flows right away.
   Frank Turley - Saturday, 07/04/09 23:46:48 EDT


"Red hot" is the incandescent color of any hot object, whether iron, aluminum or even pottery. Some things will melt, boil or vaporize before they can get red hot, but anything that can withstand the temperature will become incandescent at around 1200F. As the temperature increases, the color goes from deep red through orange to yellow and then white at around 2300F.
   vicopper - Sunday, 07/05/09 00:14:55 EDT


From what I can find out, argon gas is inert and harmless unless allowed to replace the air we breathe, then we suffocate, it is used in electric furnaces to replace oxygen preventing some components from burning, maybe overheating, it is used as an inert gas in electric lamps. When I suggested using it in a propane forge, the only possible outcome would be the displacement of oxygen, if argon could be blown through in front of the blower, I'm wondering if a lot or most of the oxygen would be displaced. I don't think it would hurt to try.

   Mike T. - Sunday, 07/05/09 01:05:48 EDT

Mike, in all the inert gas furnaces I have worked with the construction and principle of the furnace was very different than a typical forge. Most inert atmosphere furnaces are electric;y heated and therefore need no combustion air. Another design is a radiant tube furnace. Gas and air are combusted inside tubes that run through the furnace, and the tubes get very hot and radiate the heat into the controlled atmosphere furnace space. Last Is the older technology of exothermic gas furnaces. These are not very popular anymore as they have a bad tendency of exploding, and the industrial insurance agencies have rate increased them almost out of existance.
If you intend to burn fuel, you must have oxygen to combust. If you have less than a perfect mix of oxygen you will create Carbon Momoxide, and while dangerous if inhaled, this is often common to get a reducing atmosphere. If you have a reducing flame, and then inject an inert gas down stream of the flame, you will then have an even more dangerous mix of Carbon Monoxide and a non-oxygen bearing inert gas. The exhaust from such a forge would be quite dangerous. The injected gas would also cool the hot gas exiting the combuster and would make the forge much less expensive and much more expensive to operate.
In forge operations requiring little to no contact with normal atmosphere such as some grades of titanium, the billet is dipped in a slurry of ceramic that keeps the atmosphere away, and then the billet is induction heated. The induction heating is so fast that there is little time of exposure risk at the elevated temp.
If oxidation of the billets is a problem in you forge, May I suggest several less expensive things to first try in a gas forge?
1. Insulate the forge to a higher level, and coat the inside with a reflective coatinf such as ITC-100. Yhis will heat the billet quicker, leaving less residence time in the oxidizing environment.
2. Run only the billets in the forge that you can keep up with, IE don't have too many irons in the fire. Oversoaking in the forge will badly oxidize the billets.
3. Carefully tune the forge burner. Get as close to perfect combution ratio as you can, then go slightly rich. This will produce a hot flame with a little less oxidizing tendency. Be aware of carbon monoxide, use adaquate ventalation and a carbon monoxide detector is advised.
Good luck.
   ptree - Sunday, 07/05/09 08:07:07 EDT

Opps, proof then post! that is the gas injected forge would be much less effcient and much more expensive to run.
   ptree - Sunday, 07/05/09 08:09:28 EDT

You may be could successfully use an inert gas atmosphere in a muffle-type forge, but getting the work in and out is going to cost you a bunch in replacement of the argon. Hardly practical in a small home shop.

As Ptree noted, if you can achieve as near as possible to a stoichiometric ration of gas and air for your burner, you will have a neutral flame that will keep oxidation to a minimum. To minimize scaling even further, you can add a scavenging agent to the forge chamber to consume any free oxygen. A bit of coke or charcoal will do this neatly and easily, and far less expensively than trying to inject an inert gas.
   vicopper - Sunday, 07/05/09 09:25:37 EDT

Argon, Again: Air is by volume in percent,

Oxygen 20.95
Nitrogen 78.09
Carbon Dioxide 0.03
Hydrogen 0.00005
Argon 0.933
Neon 0.0018
Helium 0.0005
Krypton 0.0001
Helium 0.0000009

The Nitrogen, Argon, Neon, Krypton and Helium which are all basically inert to iron in the forge make up 80.01545% of the atmosphere. If you add more argon you are just increasing the total inert constituents and reducing the active constituents.

The primary active element is Oxygen. This is needed to mix with the fuel. If you change the balance of oxygen to inert components you will need less fuel and the forge temperature will be reduced. Oxidation may be reduced but at the expense of a cooler forge.

Adding argon would be no different than adding nitrogen, a cheaper gas. In either case you are just changing the balance of active and inactive gases.

Changing the balance may have some advantages. However, you are limited to the current maximum oxygen level unless you add it rather than the inert gas.

"Excess" oxygen would not be displaced, only reduced in total percentage. The only way to reduce it 100% is to combine it with fuel. Some forges are more efficient at this than others. Even if the fuel/air balance is perfect the fuel doesn't always use all the oxygen. Mixing the fuel and air well makes a big difference. Propane tends to stick together as it is a heavy gas. Breaking it up and mixing it well will reduce free oxygen. So, even if you reduce the total oxygen to start an inefficient forge may still have free oxygen in the atmosphere.

Note that at high temperatures the CO2 is still reactive with the iron forming CO and under certain circumstances the carbon from the CO can combine with the iron. So nothing is ever what is seems in the high temperature environment of the forge.

It is also possible to reduce oxygen in a forge by using graphite or carbon (charcoal) to use it up before it gets to the steel. . .
   - guru - Sunday, 07/05/09 12:10:59 EDT

I hear we need to stay away from galvanized metal. what about zinc plated ect..?
   - Jerry - Sunday, 07/05/09 12:46:37 EDT

Jerry, Galvanized is the same as zinc plated. There is hot dip, electroplate and shot applied (the thinnest). Hot dip is the heaviest.

Zinc fumes causes metal fume fever with symptoms like the flu. Zinc oxide attacks the lining of the lungs and repeated or heavy exposure can result in pneumonia like symptoms that turn into actual pneumonia. In these sever cases treatment for the pneumonia does little good as the chemical problem is still there.

Mild exposures often produce no symptoms but repeat exposures get worse and worse.

In some galvanizing there is lead and cadmium. Cadmium fumes are lethal in small amounts. Welders exposed to cadmium fumes either die immediately or after long painful illness. While cadmium is rare compared to zinc it is a good reason to avoid hot working any plated metal.

Manganese in alloy steel and in welding rods is also an issue. When electric welding you should always be sure to have good forced ventilation. General area ventilation is good but spot ventilation (a hose and exhaust fan) is better.

Se our iForge safety articles (top of the iForge page)
   - guru - Sunday, 07/05/09 14:18:34 EDT

on the subject of manganeese, if i am out side and up wind of manganeese alloy steel, will i be ok?
   bigfoot - Sunday, 07/05/09 14:27:21 EDT

Manganese -- I guess it depends on what's happening to the manganese steel at the time. If it's just sitting there in the sun, I don't think there will be a problem (grin). Since manganese boils above 3700 degrees, it also seems unlikley to me that any ordinary forging operation would release any significant amount as vapor or fume. Arc welding's another story. How much you'd get would depend on how strong the wind is and whether there's turbulence that might blow it back at you. Manganese poisoning is a long-term occupational hazard for welders; I may be foolish, but I don't worry too much about it when I run an occasional bead.
   Mike BR - Sunday, 07/05/09 19:19:30 EDT

that is good to know. i have melted some steel though, when i was not paying attention, but haven't we all? it seems i really need to make a forge hood. it seems it is time to break out the plasma cutter that my buddy owns (grin).
   bigfoot - Sunday, 07/05/09 20:33:20 EDT

Hey Guru, fellas, I haven't been around much lately so It's a pleasure to see that you are still at it here, getting down to brass tacks and hammering out all the details of fascinating subjects. I just saw this CL listing, wow, that's a big anvil collection, wish I could afford it. But he claims to have a Badger brand anvil. Did Postman ever find one yet?
   - Vorpal - Monday, 07/06/09 06:28:18 EDT

Sorry, here's the link.
   - Vorpal - Monday, 07/06/09 06:29:09 EDT

Anvil Collections: I know several collectors that have large collections of anvils. Some collect "name", some collect rare, some collect every decent one they see (as an investment). I do not know of the above collection but at that price one of the others is likely to buy it. When one collector I know moved he covered the entire bed of a 30 foot trailer with rows of anvils side by side.

I am currently processing photos of a collection of mostly rare and ancient European anvils. Fantastic beautiful anvils! These will be included with other collections and setup with my image collection to make a long overdue gallery of anvils. The hard part of this job is that many of my photo collection is old low resolution images taken early in the digital era and need a ton of work OR are just not very good photos other than their subject.

This is something I wanted to do for a long time but didn't quite have all the photos I thought I needed. Parts of this should be launched within a month.
   - guru - Monday, 07/06/09 09:19:59 EDT

I'm always amazed at how much expense and bother people will want to go through to deal with simple to fix problems.

If your propane forge scales too much-----tune the burner!

When I do knifemaking I commonly tune it more reducing, it's not as efficient and not quite as hot as a balanced mix but most knifesteels shouldn't be forged at the upper range anyway.

I know this produced more CO; but as my usual ventilation consists of 2 10'x10' roll up doors aligned with the prevelant wind direction with the forge in between I haven't had any problems (except for the hammer being blown off the anvil every now and then!)

Now for a very O2 poor atmosphere for a heat treat of a nearly finished blade I crush up coke or charcoal and put a bed of that on the floor of the forge. (coke doesn't blow out of the forge as much)

   Thomas P - Monday, 07/06/09 11:44:40 EDT

Guru and all,

Thank you for the input on argon. I will rethink my position on this. I have the venturi type burner and have
gone out at night, when there is no light, to try to adjust it. It seems like no matter how I adjust it, it doesn't make that much difference. I e-mailed a fella who makes nice damascus, and instead of the mig tip, he uses a plug on the 1/4 inch pipe and drills a 1/8 inch hole in it, moves it down to the elbow, and uses a blower, he told me the size blower should be 75cfm or better, and runs it rich.
   Mike T. - Monday, 07/06/09 13:02:18 EDT

i think i was born in the wrong centry because i am very interisted in becoming a blacksmith i took welding in my sophmore junior and sr years in high school if anybody could point me in the direction of a trade school that teaches how to be a blacksmith or if there is anyone out there wanting an apprentice then let me know would love to learn i will work hard to learn what is needed for me to be a good apprentice and will work hard to do as i am instructed by the master teaching me
   Matthew Warlick - Monday, 07/06/09 15:04:01 EDT

Matthew, See our FAQ page article on apprenticeships.
   - guru - Monday, 07/06/09 15:36:20 EDT

Burner Types: Mike, In blower burners no orifice is needed as the air flow is created by the blower, not the fuel jet. Blower burners are adjusted by changing the fan speed or air gate and or the gas valve.

Orifices in atmospheric burners create a high velocity jet of gas which pulls along the air. Note that changing the gas pressure only changes the total fuel/air not the ratio. The ratio is determined by the orifice size and restrictions in the air. IE, the design of the burner controls the ratio. Since the orifice cannot be adjusted short of changing the part the mixture (ratio) is adjusted by controlling the air flow. Many burners are not adjustable other than high/low.

   - guru - Monday, 07/06/09 15:54:21 EDT

I have one of each type of propane forge and adjusting the blown one is a lot easier. You can really adjust the output too from "just barely glowing" to "oops I melted my piece" However you are tied to the grid with it.

My aspirated forge has 2 burners with disks that screw down to cover the opening. I can adjust them as well; but if the jet has been bumped and is no longer perfectly aligned down the burner tube then they will not adjust much without huffing. (I keep a set of allen wrenches in my truck now so I *can't* get the forge to the demo without being able to adjust it as travelling is usually how it gets bumped out of alignment)

I bring both forges when I teach up at NM Tech at the fine arts, metals classroom.

Matthew; do you think telling us which country you live in might help? If you are in or near NM in the USA let me know and as President of the New Mexico ABANA Affiliate I'll see if I can anyone here that might be able to help.

Attention to details is very important for a job like this so I would encourage you to learn how to use the shift key when typing.

   Thomas P - Monday, 07/06/09 16:33:19 EDT

Mike T --

On my naturally aspirated forge, I added an extra gas line that connects to a needle valve downstream of the regulator. The other end of the line is just inserted slightly into the burner bell. The idea is to dump extra fuel into the burner without affecting the airflow. It works well for me. The forge is tuned so it normally runs a little bit oxidizing; I can adjust it to a neutral or reducing atmosphere just be opening the needle valve a little.

   Mike BR - Monday, 07/06/09 17:50:14 EDT

Guru and everyone,

Thank you for your responses.

   Mike T. - Monday, 07/06/09 19:03:21 EDT

Mike T: I use a system like Mike BR uses, I find it works well too.
   - Dave Boyer - Monday, 07/06/09 21:48:24 EDT

On anvil "collecting."

I had an amusing moment with the Welsh blacksmith at the Smithsonian Folklife Festival. I was showing her a picture of my forge when she asked: "Why do you have THREE anvils?" I explained that I used the gas and coal forges, along with my friends, for teaching, and they shared the big one in the middle, but she still looked at me like I was committing the typical American sin of excess.

I will remark that she was making wonderfuil stuff with minimal tools, so maybe she just saw the relative abundance of anvils in my shop as redundant. Still, each one is of a size and configuration where the three of them are more suited to various operations than if I had to chose one for all operations. Not quite as radical, but sort of like the pair that I found for a beginning friend: one without a horn and one without a heel and hardy hole.

Sunny and pleasant on the banks of the Potomac.

Visit your National Parks: www.nps.gov

Go viking: www.longshipco.org
   Bruce Blackistone (Atli) - Tuesday, 07/07/09 07:58:23 EDT

Bruce, She would go insane if she visited Josh Greenwood's shop. He currently has 5 power hammers (30, 100, 125, 500, 750) numerous anvils, swage blocks, at least 8 cones (all different) and 192 square feet of weld platen for work benches plus all the small tools that go with same. . . Its a seasonal one-man shop. His anvil collection is seperate and put away in a safe place.

I've got three working anvils on stands and two broken horned anvils without stands. They are quite usable as well both being over 100 pounds. The only "collectors" piece I have is an ancient stake anvil that I lucked upon in a trade. Otherwise my tools have to be working tools even when quite old.

About five years ago a young blacksmith/sculptor visited my shop and became a little aggregated when I would not part with any of what he thought were "excess" tools that I was apparently not using every day. He felt that I was being greedy and hogging all the available tools. . . I tried to explain that they were a lifetime collection and when I needed them, I needed them. Hw did not get it at the time.

Within a couple years HIS collection of tools surpassed mine by quite a bit. He had come into a deal and parlayed that into cash and trades and with a lot of hard work equipped his shop with every sort of tool from power hammers to forges.

While it may be part of American excess, it is also because it is POSSIBLE here and probably nowhere else. Manufacturing has been in an economic slump for decades and the result is that there is lots of equipment available often at scrap prices if one looks for it and goes after it. We also have more ROOM for such collections of equipment in the U.S. Even after the realestate spike which has raised prices to fantastic highs which will probably never go back down more than the small amount they have (8-10%) space is much cheaper in North America than in Europe.

So, while it seems to be the "American way", it could be that it is simply possible here and no where else.

   - guru - Tuesday, 07/07/09 09:39:59 EDT

Mike BR and Dave Boyer,

I'm trying to figure what I need to do. The line coming from the regulator, do I splice into it, and put a splitter
for the other line and needle valve ?

   Mike T. - Tuesday, 07/07/09 11:42:57 EDT

Mike, It depends on how you control your forge. The arrangements above use a valve to control the overall burner flow and a second to add the extra fuel. The regulator is upstream from the rest.
   - guru - Tuesday, 07/07/09 16:14:51 EDT

Space is a high commodity in countries like the UK, Japan, etc. High populations in countries smaller than the average American state must feel a squeeze on land. I too have three working anvils, four vises, 5 grinders, etc. For a home based shop, I could understand feelings of "over tooling" from others, but it might just be pure jealousy. Peter Parkinson's book "The Artist Blacksmith" shows his shop chock full of all types of things (UK), but it's a WORKSHOP in a warehouse, nothing at all like my humble cellar work area. I think the best thing to say to anyone who complains that YOU have too many anvils is the reply by asking if they only work with one hammer? One set of tongs? One saw?
   - Nippulini - Tuesday, 07/07/09 17:50:08 EDT

Being a scrounger, that has had the luck to have extra good access to industrial excess materials, i am very guilty if that is the word of too much. My shop, a hobby shop has a bigger footprint than the house:) Filled with lots of stuff industry threew aside, like a 14.5" by 54 Lodge and Shipley, that I spent a couple of years of off and on work to get running. Cost maybe $300 for an excellent tool makers engine lathe. I have 3 drill presses, a antique mill, a cast off belt sander, two anvils, one 454# non traditional anvil, 4 forges, and then there is the wood working stuff the auto mechanic stuff the electronic stuff, the jewlers shop, and so forth. But while I don't use every tool every day, I do use every single tool in every single group, on a regular enough basis to keep them.I have sold a homemade anvil that was not used any longer, given away a few tools that were not used and am always weighing whether to keep of move tools on. I figure if it is a hard to find tool and I use it once everyother year no question, it stays. Once every 5 years is a harder question.I also have tools inherite from my Father, both Grandfathers, a Brother's Father-inlaw, and some uncles, all of whom are now deceased, cherished those tools, and they will be cherished until I find someone who will cherish them as I do when I no longer need them. I have a son and a daughter that may both qualify in a few years.
   ptree - Tuesday, 07/07/09 17:58:41 EDT

Not to forget those who've visited my shop and wanted me to have more. I've been told I needed a lathe, a treadle hammer, a brake, a squaring shear, etc. My usual response is, "Gimme the money." One of my old buddies answered thusly, "If I had enough money to get ALL the tools I wanted, I'd have enough money to retire."
   Frank Turley - Tuesday, 07/07/09 18:26:12 EDT

Not to mention building up a set of tools for each of the grandkids so there will be no fighting "later". Of course if any of them are interested in smithing they will get their share "sooner".

I'll have to start allocating a drawer for each of them in a shop cabinent to hold *their* stuff when they come to visit; gotta plan ahead they just got out of the hospital almost a week ago!

   Thomas P - Tuesday, 07/07/09 18:39:12 EDT

On my forge, I control the main burner by adjusting the regulator. Because the extra gas line is controlled by the regulator also, the mixture stays more-or-less constant as I adjust the overall heat. If you leave the regulator fixed and adjust the main burner with a needle valve, you'll probably want to tap the extra line in downstream of that. Otherwise, you'll need to need to adjust both valves if, say, you want to back the burner off once the forge comes up to heat. Tapping the line downstream of any shut-off valve is a plus as well (grin).

I use a simple Reil-style burner with the orifice mounted on a cross tube. I just pulled the cap off the far end of the cross tube and installed the needle valve for the extra line there.
   Mike BR - Tuesday, 07/07/09 19:07:19 EDT

OR how many mind numbing video games they own/play. . .

The serious tool head has what WAS a bedroom setup for woodworking. . An enclosed porch with a buffing rig mounted on the window sill and oil stains on the picnic table from overhauling a motor, a storage shed stuffed full junk and excess machines. . .

Some keep their tools under a tarp or in a shed and drag them outside to use them. "Shade tree mechanics" don't work under the tree for the shade but for the big limb to hang a chain hoist to pull the engine. Nails on the tree substitute for hooks on the wall. . .

Our friend Orgin in Sweden kept his forge tools at home and would haul them on a bicycle to his rented shop space. The space was lousy, unsecureable (thus hauling the tools) but it was a place to work.

Some interests take less space and are not so equipment heavy as blacksmithing and fit better into that spare bedroom. . .
   - guru - Tuesday, 07/07/09 19:09:05 EDT

Mike BR

Thanks for the info.

   Mike T. - Tuesday, 07/07/09 20:41:40 EDT

Mike T: My burner is like Guru described. I use a regulator set at a pressure that will give 30 PSIG at the burner. I have one valve that feeds the MIG tip that I use for the orface and another that just dumps extra gas into the air stream to control the mixture. I have a pressure gage between the valve and orface [not really needed] and set the mixture by flame color. No extra gas gives a good hot flame, but by adding extra gas I can make a neutral or reducing atmosphere in the forge. The burner runs well fron about .75 PSI to about 50 psi. I find 30 psi to be more than enough for the forge, at that pressure there is a tremendous ammount of dragon breath. When the forge gets up to temperature I cut it WAY back.
   - Dave Boyer - Tuesday, 07/07/09 20:47:09 EDT

Clarification: The feed for the extra gas valve is downstream of the flame size ajusting valve, the mixture stays in sync fairly well as the flame size is changed.
   - Dave Boyer - Tuesday, 07/07/09 20:58:57 EDT

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