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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 April 22 - 30, 2000 on the Guru's Den
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How do I punch an 8mm hole in 8mm thick hard, or high-carbon steel?. Of course drilling won't do it and I have no specialized equipment except my forge, anvil etc.
Tanks in advance, Dave.
Dave. - Saturday, 04/22/00 00:14:17 GMT

Is there any chance that some one might know were i can get a fairly basic barell helm pattern coz i just cant seam
to get my pattern right
Blade  <Lostsoul at moonshinehollow.com> - Saturday, 04/22/00 00:54:29 GMT


Get a strait punch the right size. Heat the stock to a good bright red.

Punch about 2/3rds of the way through. Turn the stock over, you'll see a darks spot where you were punching. Back punch the biscuit out. Quench the punch as you turn the stock over so it doesn't get too hot.
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Saturday, 04/22/00 01:01:40 GMT


Atli might answer this, if he doesn't have on, contact me, I think I can find one for you.
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Saturday, 04/22/00 01:07:22 GMT

Drilling vs. Punching: Dave, How hard of steel? Anything up to 45-46Rc can be drilled. Many medium carbon steels and spring temper steels can be drilled in the hard condition. Drilling must be done with coolant (water or oil) and with high enough pressure to CUT and run rub. A drill press (evan an old beam type) is required.

Paw-paw's punching instructions are correct. Punch tool steels at the highest recommended forging temp. Lubricating the punch with grease helps keep it cool. On large or deep holes coal powder is often used to lubricate and cool the punch.

Barrel Helm: Blade, have you tried making one out of poster board? Cut and fit, add and subtract material until it works, then use that as your pattern. If you can't figure it out with paper, scisors and tape then it will be hopeless in steel. However, remember that steel can be stretched to form it so you can do more with it than with paper.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 01:32:10 GMT

Thanks for your help on punching through high-carbon guys. One more Q for now: If the tungsten tip of a tig welder stays hard even when hot, is there a reason I couldn't or shouldn't make a punch out of tungsten for that reason?.
Thanks again, Dave.
Dave. - Saturday, 04/22/00 02:31:09 GMT

I am a artist who is looking to find the original man who started making sculptures with cut nail. I saw one of his works in the mid 70's and can not find out what his name was. Today over the last 5 years, I have made 6 sculptures just because I saw his work then, can you name this nameless man. Thank you Dennis, Brewster NY
Dennis  <DHymo5857 at aol.com> - Saturday, 04/22/00 02:46:38 GMT

Dear Guru,
I would like to build a high eficiency square forge hood. Centar has one in their catalouge for big bucks. I am a Tin Man and have lots of scrap. I am going to order a firepot from Centar and want to build the rest. I have an old cast iron forge with a flat tuyre and it keeps cracking. You advised me to bolt it together. I did and it cracked another place. I think it will make a good display piece. I enjoy making items from iforge. I especialy like to make flowers. I made a lid lifter that turned out well. Thank You! Another silly rookie.
Steve P  <Steveabc> - Saturday, 04/22/00 02:47:08 GMT

I am a artist who is looking to find the original man who started making sculptures with cut nail. I saw one of his works in the mid 70's and can not find out what his name was. Today over the last 5 years, I have made 6 sculptures just because I saw his work then, can you name this nameless man. Thank you Dennis, Brewster NY
Dennis  <DHymo5857 at aol.com> - Saturday, 04/22/00 02:48:12 GMT

I'm trying to find any maintance and foundations plans for a Bradley hammer. The hammer is #250. The owner is ready to pour the floor for his new shop. He loaned out his paperwork and now it is lost. Any help would be appreciated -thanks
pat  <patndee at hotmail.com> - Saturday, 04/22/00 02:57:18 GMT

Dave Tungsten dosen't stand up to shock worth a durn. It also won't handle any lateral forces. Whithstands compression and heat. Verry pore choice of material for punch. Use S-7 or H-13 if available.
kid  <n/a> - Saturday, 04/22/00 03:21:02 GMT

Tungsten: Dave, W (wolfram) is a very high melting point metal 6140°F / 3410°C (the highest of all metals) and is one of the denser metals at 19.3 g/cm3.

Its hardness is Brinell 290 (less than Rockwell 21c) as apposed to Tungsten Carbide with a hardness of 550 Brinell (~Rockwell 54). . . About the same hardness as most tempered tool steels BUT it is very brittle as most Tungsten is a sintered powder metal product. You are better off with high carbon steel. You CAN get fancy and use hot work steels such as H-13. . . but it is not necessary.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 03:21:40 GMT

Original Artist: Dennis, cut nails have been around since the mid 1800's. Your man MAY have been the first but it is unlikely. I've seen work made of horse shoe nails and copper wire that was beautiful but these were relatively young craftsfolk. I've not met your guy but maybe one of our other readers may have.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 03:28:43 GMT

Hood and Forge: Steve, I kind of thought the cracking problem wasn't going to quit. Once CI parts are stresed to the breaking point by heat they are often full of cracks. Welding one spot just opens another and you are off on a meery chase. There ARE techniques to work around the problem but once the damage is done its VERY difficult to stop.

If you need more views of those hoods try the last pages of the ABANA edition of the NEWS and the AFC edition. Don't make the inlet larger than necessary. The high velocity at this restriction is what makes these work well. Use galvanized, stainless or something heavier than sheet metal. Forge hoods tend to rust out in just a few years due to sulfur in coal that makes acidic deposits in the flue and hood.

Forge pans are best built of 1/4" (6.35mm) steel plate and angle iron.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 03:41:02 GMT

Bradley Foundation: Pat, the foundation should be seperate from the rest of the floor.

Since Bradley's have a seperate anvil the foundation should extend in front of the hammer a significant distance since idealy the the cg of the foundation should be centered under the anvil.

Studs OR anchors can be cast into the concrete. The holes in ALL these old machines varied significantly enough that dimentioned plans are worthless. Either carefully measure the bolt pattern taking diagonal measurments to determine squareness OR make a template by setting the hammer on a sheet of plywood (paper?) and tracing the holes.

Anchors can be heavy hex nuts welded to tubes (pipe) so that bolts can extend through. I weld the anchors OR studs to a framework of re-bar to set in the hole. If they are right when you weld them up, they will be right after the concrete sets. Put duct tape over both the tube and the nut end to keep concrete out.

The depth of the foundation is partialy determined by the soil conditions. Dig until you hit hard clay and then dig a little more (2 ft total min). IF you don't reach hardpan then you may need to dig as far as possible and put in a stacked wood foundation.

Width of the foundation should be such that the bolts or anchors are no closed than about 10" from the edges of the block.

When the hammer is set a shim of plywood or hardwood boards should be placed under the hammer and anvil.

I isolate these inertia block foundations from the rest of the floor with a dozen or so layers of roofing felt. The sides of the block need to be formed up square and clean so they don't key to the rest of the floor. Anchor nuts are nice because you can skid the hammer over them rather than lifting it. They also don't present a trip hazzard like studs.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 04:04:27 GMT

Finally finished the plumbing and valve installation on my air hammer. The first time I plugged it in the ram shot up to the top and stuck. I was ready for this however, as William Cottrel had warned me that if it did that to reverse the pilots on the roller limit switch. After that it found the middle and seems fairly stable. However, it does have a tendency to go up and down on it's own for unknown reasons ( no input from the exhaust valve). Seems also slower than I thought it would be. There was some dirt on the guide from grinding and assembly so I oiled and flushed the guide out. If you remembered I used a hydraulic valve from a dump truck as my cylinder, do you think it's possible this might be the cause of some of the problems? Hoping that "breaking" it in might also solve the problems. TC
Tim Cisnros  <blacksmith at starsticker.com> - Saturday, 04/22/00 04:11:56 GMT

Cylinder: Tim, cylinder velocity/response can be slowed by hydraulic seals. They tend to use multiple seals where air cylinders use one.

The upper limit effect is handled by slowly applying the air and letting things get primed to go. BUT, you need an air, hydraulic OR spring snubber at the top of the stroke to take the overtravel. . .

The Simple Air hammer circuit is not the best. The Alabama Forge Council modified air circuit plan has a regulator in the circuit to balace the cylinder forces caused by the shaft reducing the force on the up stroke. I've looked at using two pilot valves (upper and lower).

These hammers use a delicately balanced design that relies a lot on timing and inertia. The pilot valve must be tripped before the ram is all the way down so that the shuttle valve has time to react and apply return force BEFORE the stroke is complete.

Up and down on its own???? May be bad seals in the cylinder? Try taking off one line (bottom) and applying air to the other (top). With it squeezing the dies shut there should be no leakage out the open port. You may have also reversed the pilot lines in error. Normally when you apply air to these hammers it raised the cylinder. Do it too quickly and it will slam against the top stop.

If its going up and down on it own where IS the air going to?? You can't have motion without air moving. Leaks??? Open valve (exhaust??).

Study it for a while. There WILL be a logical explanation.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 05:05:24 GMT

MORE: Tim, keep track of your problems and errors. These can help others more than sucesses. . . OHHHHH THAT's what I did wrong. . . Trouble shooting guides are hard to come by because we forget to take notes.
- guru  <guru at anvilfire.com> - Saturday, 04/22/00 05:07:36 GMT

I was given a 200 pd. Kohlswa anvil. I can't find any info about it. Can you tell me about the history of this type of anvil? Also its been outside in the weather for many years. Can I grind the surface flat without damaging the surface? It looks to need about 1/32"-1/16" removed. And if i have to weld on it, the corner is nicked 1/4", can i use a 7018 stick, preheating it first? I've been a welder for ten years and feel drawn to blacksmithing because of its appeal, my friend tell me its long over due. Well, thanks for the help, Will
Will  <continuum at freewwweb.com> - Sunday, 04/23/00 00:39:06 GMT

Free Anvil: Will, be carefull with that kind of talk you make a LOT of people that have been desparately searching for an anvil VERY jealous!

Your Kohlswa is a Swedish cast steel anvil. They were inported by the Swedish American Steel company up until 1960 when when Centaur Forge took over their import. See the current NEWS for details.

The old Kohlswas are very good. My first anvil was a 100# Kohlswa and I currently have a 300# Kohlswa. Their only fault is that they are too hard and the edges are almost always chipped. Dressing the edges with a grinder is best. Since anvils ARE hardened tool steel I generaly do not reccommend repairs unless they are in really bad shape. After dressing the top with a grinder, dress the edges and put a slight radius on them. Many old references called for 1/4" chamfers but this is considered sacrelidge today even though it was good advise for anvils used in shops where they were used by everyone and not necessarily trained blacksmiths.
- guru  <guru at anvilfire.com> - Sunday, 04/23/00 01:35:17 GMT

Dear Guru,
Where can I find the schematic diagrahm of a coreless
induction furnace or deep information on the subject?
Abraham  <xcherian at swbell.net> - Sunday, 04/23/00 02:34:16 GMT

I am trying to keep a log of all the trial and errors of building this air hammer. As you mentioned I am using the Alabama Forge council (Mark Linn) schematic. It is a beautiful thing to behold! I can adjust the flow control and the dies "kiss" or I can open the control and get a heavy hit. I am putting the final touches on. IE... the foot control, painting, plumbing lines neatly tied, etc..Will be in touch with some photos soon. TC
Tim Cisneros  <blacksmith at starsticker.com> - Sunday, 04/23/00 02:54:12 GMT

What is the difference between an aught and a triple
aught, how are the sizes written, and which is larger?
Buck  <Buck228125 at aol.com> - Sunday, 04/23/00 04:12:02 GMT

Aught is 0 triple aught is 000 Not sure of the size tho
Ralph  <ralphd at jps.net> - Sunday, 04/23/00 05:05:22 GMT

Induction Furnace: Abraham, On our links page we have a link to ASM International. They have a book and videos in their bookstore. There is also basic information in the ASM Heattreaters Guide. The same references may also be found in many engineering school libraries as well as the library of congress. I regularly use the University of Virginia Science and Engineering Library. Have had occasion to camp out there a week or so. A few nights in a motel and a deposit on a copy card is well worth the investment. Check the nearest college or university near you.

Besides these references you may also need texts on electrical engineering and general engineering. McGraw-Hill is one of the largest publishers of engineering references. They have a web site and engineers book club. I reccomend both old and new editions of Marks' Mechanical Engineers' Handbook. You will also want a suscription to Foundry Magazine, one of the many Penton publications. Foundry will have advertisment from hundreds of suppliers of equipment and components. Often suppliers catalog information is the best up to date source on the state of the art. For standard hardware and wire get a SquareD Digest from a local distributor and ask if they have a Houston Wire catalog. Houston carries everything from thermocouple wire and computer cable to high voltage transmission cable.

I can reccommend PLC's and controllers but normally I use whatever is the product of the day that my local supplier is carrying and supporting. For maintainability I suggest industrial PC based rack mount controllers. They are more expensive than the propriatary stuff but the component parts (cards) can easily be replaced and are very standardized.

Deep enough?
- guru  <guru at anvilfire.com> - Sunday, 04/23/00 05:13:07 GMT

ASM Search: Abraham, use 'induction heating' not furnace.

0, 00, 000, 0000 Buck, the numbers are based on various gauge systems where the higher the number the smaller the object. In wire 28ga is real small while 0 is about the diameter of your pinky (too late tonight to look it up). . However, most of these sytems started out with a bad assumption that whatever '0' was is was a big as you would ever need. Of couse THEN you needed something bigger and you have 00, 000, 0000. . . . Kinda' dumb like all number and guage systems. There is no standard. Ought wire and ought buckshot have NO relationship. In metal plate they rapidly go to measured dimensions instead of gauge sizes and since the various gauges are not standard it is reccommended to use decimal sizes for the small stuff now.
- guru  <guru at anvilfire.com> - Sunday, 04/23/00 05:25:12 GMT

dear guru im a shop fabricator,ironworker,local #5 Wash,DC
im looking for leather aprons any sites to reccomend ?
steve  <ironspud at juno.com> - Sunday, 04/23/00 14:02:30 GMT

Thanks for the reply on the Bradley Hammer. That is how I set my Fairbanks up. But I hadn't concidered the seperate anvil sow on the Bradley. Hopefully this will help us get Steve's foundation laid out. Thanks again
pat  <patndee at hotmail.com> - Sunday, 04/23/00 16:18:42 GMT

Leather Apron: Steve, I purchase mine from my local welding supplier. However, I know that in DC you can purchase 500 different type of paper clips and get escort service ;) 24 hours a day but can't buy a simple drill bit.

Try Kayne and Son or Centaur Forge. Its easier than going to Baltimore or Richmond.
- guru  <guru at anvilfire.com> - Sunday, 04/23/00 17:41:42 GMT

Leather Apron,

Steve, I made my first leather apron from a leather log carrier I picked up at a local Home Quarters. Wasn't the best apron in the world, but worked until I could get a real one.
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Sunday, 04/23/00 17:47:17 GMT

I have a anvil marked HADFIELD AND SANDERSON SHEFFIELD. Then the weight of 123lb. In what time fram would this anvil been made? My greatuncle gave it to me and told me it came to Alabama in 1830 with his family. Could this be ture?
Thanks for any help. John Thomas Mott
John Thomas Mott  <anvilstriker at mindspring.com> - Monday, 04/24/00 00:33:56 GMT

John Thomas,

Quite possible. From ANVILS IN AMERICA, Richard Postman, pg 73.

English manufacturer, located in Sheffield England.

Don't have a time frame, but the 1830 date is in the bracket right era.

Is the weight marked in pounds, or in English Hundred weight?
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Monday, 04/24/00 00:44:09 GMT

I have a post drill made by the Forge & Blower Co of Kitchner Ont..The number of the drill is 614..It has a broken arm on it that controls the amount of down stroke..I would like a picture of this drill so I could make that piece..I am not sure which way it is to go.. Any hints. Thanks Barney the Blacksmith of North Bay Canada
Barney  <barney at vianet.on.ca> - Monday, 04/24/00 01:14:27 GMT

Drill: Barney, we have two pictures of drills on the 21st Century page but neither have the lever type auto feed.

Most of these are bent or angled about ~160° at the pivot and have a paw that when engaged in the feed wheel set at about 45° The end that rides on the crank/cam is bigger at the point that rides on the cam to act as counter weight. The paw at the top is about 3.5" long.

These were a cast part and it was common for them to get broken in handling. If the arangement above seems right I'll see if I can post some photos and drawings of the type with that style part. No Canadian machines but a Champion that was probably copied.
- guru  <guru at anvilfire.com> - Monday, 04/24/00 01:50:46 GMT

Yes please do..It sounds the same..If not I should be able to start something....
Barney  <barney at vianet.on.ca> - Monday, 04/24/00 02:20:51 GMT


If you don't have one handy, I'll have the trailer set up this weekend for a demo, and that is the type pawl (note spelling! grin) that is on the drill mounted to the trailer. I can take a digital of it if you want.
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Monday, 04/24/00 02:28:44 GMT

OK, where's the spell checker!

That should be guru, of course.
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Monday, 04/24/00 02:32:04 GMT

Sand, (so i've been told) is actually one of the best natural fluxes for forge welding (even different steel types). Is this true or do you know of a better type of natural flux that can do a similar job?.
Thanks, Dave.
Dave. - Monday, 04/24/00 04:33:11 GMT


There is sand, and there is other sand.

Some types work well as flux, some don't.

20 Mule Team Borax works a lot more reliably. (NOT Boraxo, plain old borax)
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Monday, 04/24/00 04:53:14 GMT

Guru, the questions on power hammer foundations raised the neuron level, I have a 50# LG, It sits on about 8" of concrete and plywood and some old mud flaps. I recently drilled the cement and put in lead anchors and lagged it to the floor to keep it from walking. I have been told not to tighten it but just let it bounce around. Oh yeah, I have the electric motor mounted on top of the hammer, so its sorta top heavy. Its sorta scary how it wobbles. Also have been advised (BS Journal) to put it up on wood (RR ties) and attach a 'handle (footle)' to the treadle. Any thoughts before I go thru another cycle of moving this guy?
PS I have the book.
Tim - Monday, 04/24/00 13:38:09 GMT

I live in the UK but have just visited Mauritious, a small island in the Indian Ocean, in order to see my wife's family. My brother-in-law who lives there wants to start a small metal working business and needs to build a small forge as a means of earning a living for his family. He is currently a plumber and has worked with metal making wrought iron railings. Could you let me know where I could locate some plans for a forge/furnace?
Many thanks
David Crowson  <david.crowson at mencap.org.uk> - Monday, 04/24/00 14:26:57 GMT

Really pure silica-sand works as flux, but my experience is that it works best with true wrought-iron since it takes high heat to be sure that it all liquefies and gets out of the weld. We have a "mine" locally that exports this type of sand for water-filters and stuff.
Olle Andersson  <utgaardaolle at ebox.tninet.se> - Monday, 04/24/00 15:35:08 GMT

I think PawPAw is trying to tell you something! (gugu!)
Either that or his age has caught up to him! grin!
Ralph  <ralphd at jps.net> - Monday, 04/24/00 15:50:20 GMT

Hammer Foundations: Cushioning serves several purposes. It compenstates for irregularities between concrete and cast iron reducing stress on both. The bases of most machines are not finished and can be considerably out of flat. Cushioning distributes the shock load over a larger area thus reducing the tendancy to damage the concrete. Cushioning alows the anvil to move during blows actualy producing a more penetrating blow and giving the metal more time to flow than when hard mounted. Modern metalurgy prefers hydraulic presses over hammers because of this.

Little Giant called for their machines to be hard bolted to a concrete foundation. I prefer a rubber or wood pad between the base and concrete and rubber pads under the washers holding the machine down. It should not rock back and fourth. Which, by the way, a properly balanced machine does NOT do.

Bigger machines with seperate anvils often have the anvil set on stacked wood timbers (like on steam hammers) and the frame bolted to the concrete floor (or wood stringers set in the earth). The wood timbers act like a big shock absorbing spring cushion and let the anvil move down and then spring back between blows.

Today one of the best reasons to put a Little Giant on timbers is as risers over the floor. These machines are generaly built for short smiths or for doing work that doesn't require looking close. Average folks need to raise the dies 4" to 6" and taller folks at least 8".

A 25-50 pound hammer doesn't need a special foundation. I would put it on a wood load distribution pad giving it more wheelbase (to resist the rocking). This way the hammer also has a degree of portability. Think about how many confrences where they bring hammers in to setup. Most are not well mounted and a 4x4' base would take care of a lot of problems.
- guru  <guru at anvilfire.com> - Monday, 04/24/00 15:51:50 GMT

Sand flux: As Paw-Paw mentioned there is SAND and then there is sand. . Certain clean sands have worked but there are as many types of sand chemicaly as there are minerals. The majority of sands will just plain prevent a weld from being possible. Sands with refractory metals and oxides will just become embedded in the iron and do no good at all.

The boron in borax (which is a mineral deposit that is mined from old lake beds) is the active ingrediant and it occurs in various minerals. Flourite or flourspar contains flourine a VERY reactive substance and an excelent flux for alloy steels. Flourine is also a poison gas like chlorine. . .

So, what IS the chemical composition of your local sand? I don't know what my local creek sand is but I DO know it is from a combination of minerals as well as having a large amount of clay and organic matter. . . Not suitable for flux at all (I tried it). On the other hand I have seen our local red clay used with great success.
- guru  <guru at anvilfire.com> - Monday, 04/24/00 16:05:08 GMT

Indian Ocean Forge: David, The forge will depend on the fuel available. Charcoal can be made but is sometimes difficult from tropical woods. Charcoal forges need to be a little deeper than coal forges. Propane and fuel oil are possibilities if coal or charcoal are not available. On our plans page we have a starter "Brake Drum" forge that is a good low cost way to explore solid fuels. There is also gas forge burner plans and links to sites with complete plans from there.
- guru  <guru at anvilfire.com> - Monday, 04/24/00 17:10:08 GMT

How do you anneal , harden and temper air hardening steel. I have some a2 round. I tried to anneal it by heating to cherry red then buried in sand for a slow cool.File still can't scratch it.
Dennis  <sawmill at erols.com> - Monday, 04/24/00 17:32:31 GMT

Do you have any information on where I can find pitch for doing repousse? Also, do you have any advice for someone who is just getting started with repousse(basic techniques, sheet size, etc.)? Thank you very much.
kevin  <none> - Monday, 04/24/00 19:21:17 GMT

Annealing Air Hardening Steel: Dennis, Hardening has to do with the rate of cooling. Air hardening means a "quench" in room temperature air. Sand would have cooled the steel as fast or faster than air. Cooling rate is critical. With a few exceptions all your alloy tool steels must be cooled at a rate of no more than 40°F per hour. In most cases this requires a temperature controled furnace. However, annealing mediums with very low themal conductivity can be used sucessfully. Quick lime is used as it is very light. Vermiculite is also used though I have no experiance with it. In the case of an air hardening steel you would want the annealing medium heated to near the annealing temperature. The annealing temperature of A2 is 1550 to 1600°F. It must be heated slowly and should be held at temperature for roughly 1/2 hour. In some cases the anneal is performed in the furnace. After the part has been heated for the required time the furnace is shut down and allowed to cool with the contents and a closed door. The mass and insulation of the furnace assures a slow cool.

The hardening temperature of A2 is a little higher 1800°F and should be held there for about half an hour. It is cooled to room temperature in air and then immediately tempered by heating to 350 to 1000°F depending on the hardness desired. Hold at the tempering temperature for 1 hour.

I harden and temper A2 in my gas forge using stainless foil to prevent oxidation. As soon as the part is cool enough to strip the foil I return it to the same forge (having been shut off on removal of the part). The forge at this time is roughly 450 to 600°F. I'll leave the part in the forge while both cool. If the part is a complex machined shape or subject to impact, tempering a second time is reccomended.
- guru  <guru at anvilfire.com> - Monday, 04/24/00 19:22:15 GMT

I have a Wisper Momma Gas forge (model 2) with the back door. I'm looking at the Wisper Momma open end model as the next forge to buy. I'm needing to reline my forge. IS IT POSSIBLE TO CONVERT THE RELINEING KIT OF THE OPEN END MODEL TO THE (MODEL 2) FORGE???????
Smurf  <bove at semo.net> - Monday, 04/24/00 22:00:19 GMT

Dear Guru...I am presently curating an exhibit of artist-blacksmith work at the Seattle-Tacoma Int'l Airport, and need some basic historical information on the artist-blacksmith movement in North America. I am not a blacksmith and will not go into the long story of how I happen to be curating this exhibit, so I have no library or subscriptions to consult on this subject. (the hotmetal in my email address refers to the iron and bronze foundry work that is my and my husband's occupation.) Can you suggest a source for this general historical information. I haven't much time. - Judith
Judith Caldwell  <caldwellhotmetal at aol.com> - Tuesday, 04/25/00 00:28:18 GMT

I have an anvil I am trying to repair.some of the corners are chipped. I've tried welding up and grinding the edge back it looks good but its to soft, i have used 6013 rods and a 225 amp welder . Not really a blacksmithing question or maybe it is . Do you have any suggestions?
thanks ,
ED  <EEOSWALT> - Tuesday, 04/25/00 01:49:06 GMT

Kevin, Jewelers Pitch for repousse. Cann be found along with other metalsmithing supplies at:
Otto Frei & Jules Borel Co.
PO Box 796
126 second St.
Oakland Ca.94607
Phone 800 772-3456
fax 510 834-6217

San Francisco Branch
760 Market st.
Room 905
SF CA. 94102
Tim Cisneros  <blacksmith at starsticker.com> - Tuesday, 04/25/00 02:58:16 GMT

The Artist Blacksmith Movement: Judith, I sent your response my mail.

Anvil Repair Ed, Good anvils are made of hardened tool steel and repair methods are the same as for press dies and other critical tool steel parts. Arc welding on a cold anvil may produce more problems than it solves. This is one of the MOST common blacksmithing questions and the most common answer is don't do it. There are responses to anvil repair questions in almost every archive of this page as well as just a few posts above.

See our anvil series on the 21st Century page.
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 03:23:39 GMT

NC-TOOL Forge reline: Smurf, the two forges are exactly the same size but the door and back have holes that are in different pieces of the liners. I haven't seen a reline kit to know if the holes come precut. If they are you could take the pieces you will have to carefully cut out of the ends and fill those in the door and back (side). It won't be as good a it could be but it will work. The piece in the door will need to be glued in with ITC-100 or the sodium-silicate product used to glue Kaowool into frunaces.
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 03:39:22 GMT

Dear Guru,
I've had some experiance in metal working over the years, such as in the working world and including shop class in High School and tech school.
My question is concerning heat treating metal for hardness. I intend to harden an operating rod on a machine to prolong the life of the part. As I recall from my experiance in heat treating (consisting of heating a homemade chisel) the object is to heat the metal followed by a cool down in an oil bath, then repeat the process, thereby hardening the metal to a greater degree on each ensuing cycle. I intend to try to duplicate this procedure with a hand held propane torch and a pail of oil, the metal rod is approx. 2ft. by 3/8 in. I have hopes' that you may have some words of wisdom to help me along.
Thank you in advance,
Tracy  <tracyammo at aol.com> - Tuesday, 04/25/00 04:26:46 GMT

I am trying to locate a supplier of mica for a lampshade. Do you know of a possible supplier? TC
Tim Cisneros  <blacksmith at starsticker.com> - Tuesday, 04/25/00 04:52:17 GMT

Smurf, The reline kits are standard and the same for both models. The holes are not pre cut; you have to cut opening where needed with an old hacksaw or saws all blade.
Bruce R. Wallace  <WalmetaLwk at aol.com> - Tuesday, 04/25/00 04:58:06 GMT

Dear Guru, I have a 3 1/2" Rock Island model 851 bench vise with swivel base and swivel "stationary" jaw. The only problem is the swivel jaw is missing. The tag rivetted on it says it was made by The Birtman Electric Co., Rock Island, IL. Do you have any info on this vise or the company? Any ideas on getting a replacement Jaw holder shot of machining one? Thanks a lot.
Randy  <rz at excelonline.com> - Tuesday, 04/25/00 05:15:39 GMT

guru: induction heating, with all the referances you gave longer up, is building an induction oven something that is better left to those who dont have to ask?
what does the electromagnetic stuff do for or against your helth?
would a 240 volt 60 amp 3 phase electric system be enaugh to heat 10x10x10 cm of steel to welding heat faster than coke?
what would a oven cost if bought ready to plug inn?
what would happen if one touched the wire with the steel one is holding?
Stefan  <stefan at imv.uit.no> - Tuesday, 04/25/00 05:53:56 GMT

Can anyone point me in the direction of a bladesmithing tutorial for beginners, or a site that can give me step by step instruction?. Any help would be greatly appreciated, Thanks, Dave.
Dave. - Tuesday, 04/25/00 06:05:44 GMT

Looking for Cor Ten supplier, nearest to Memphis.
Thanks, Roy
Roy Tamboli  <roy at tamboli.com> - Tuesday, 04/25/00 10:57:11 GMT

Heattreating: Tracy, I'm afraid you have a bunch of missinformation. First, there is no need to "reharden" in phases. It is generaly a bad practice. Second, hardness does not necessarily prolong the life of the part. Hardness prevents wear and increases the amount of deflection a part will sustain and return to normal BUT hardness makes parts brittle and in the case of a long part such as you discribed could shorten its life due to breakage. Hardness and ductility must be in the proper balance.

The quenchant may be brine, water, oil or air depending on the type of steel. Low carbon steel will harden slightly but not to the degree of spring or tool steels. The parameters of the heattreating sequence is determined by the type of steel. Once hardened, the part must be tempered. Tempering is the reheating of the part to a temperature well below the hardening temperature to reduce the hardness and increase the toughness. This may range from 350°F to as high as 1350°F depending on the steel and the hardness desired. On very hard critical parts double tempering (doing more than once) is recommended. Tempering helps reduce hardening stresses and double tempering is cheap insurance.

My experiance with a propane torch is that you MIGHT get a short section, 1/2" or so of that rod up to hardening temperature. Attempting to harden the rod in short sections will result in warpage with hard and soft places, probably ruining the part.

In the case of a long slender rod the best thing to do is purchase an alloy material in a pre heat treated condition. OR have an expert do the hardening and tempering. You will have to provide him with the material specs.
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 13:16:26 GMT

Induction Furnace: Stephan, you are right. And its not a one discepline job either. The electrical and coil design need to be done by an Electrical Engineer that specializes in induction coils. The controls by a DC controls and power supply expert. The refractory specs by an engineer experianced in foundry coupla and ladle design and the physical structure by a mechanical engineer. Its a big high tech project.

Your 240VAC 14KVA power supply could heat that block of steel to welding heat as a resistance furnace (kiln) in about 4 - 6 hours, but only if the furnace were sized for that particular job. The point of induction heating is that it is fast, heating from the inside out. Fast takes more power. There is no substitute for energy. Cost? In this case there is no substitute for deep pockets either.

Safety is a design issue. Generaly there is no exposed wiring in induction furnaces. The fact is the wireing and coils are often water cooled. The coils are also insulated from the work by refractorys. There is a lot that goes between the wiring and the work piece.

We have some information here on an historic process that was a resistance heater using water as one contact. It was called the Lagrange-Hoho water pail forge. A 240VDC circuit was conected to a metal pail full of water and a pair of tongs. The work was gripped with the tongs and thrust into the water. Now THAT is dangerous!!! For obvious reasons the system did not catch on.

The questioner above didn't say what he needed the information for. He may have been an engineering student with a research project, A buyer or foundryman trying to learn enough to wade through sales technobable. OR another backyard designer with a gleam in his eye.

Often folks asking questions here are from other countries where sources of industrial information are much more difficult to find than in the U.S. That's the thing about the Internet, you can't always tell where someone is from by their e-mail address. You'd be surprised how much mail I get from overseas that has an AOL address. . .
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 14:00:34 GMT

Rock Island: Randy, I looked in the Thomas Register without any luck. Folks have asked about Rock Island before and I've had no luck finding information on the company. I suspect that fabricating a new jaw is the only alternative (short of finding one that something else is broken).
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 14:27:14 GMT

MICA: Tim, I don't know any of these but I pulled the best bets from Thomas Register,

Cleveland Mica Co.
Lakewood, OH

Mica Sheets: Thickness From .010 To .060 & Standard Size Of 36" X 36". Custom Sizes Available.

Mykroy/Mycalex Ceramics
Clifton, NJ

Glass Bonded Mica Composites Are Moldable/Machinable Ceramic Materials.

Cogebi Inc.
Dover, NH

Parts; Rigid & Flexible Sheets.
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 15:04:49 GMT

Cor-Ten: Roy, This is a close as I could find.

Central Steel Service, Inc.
P.O. Box 326
Pelham, AL 35124
FAX: 205-663-3391

EMAIL: kwoods at quicklink.net
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 15:10:24 GMT

Bladesmithing: Dave, you will not find complete information anywhere on the net. Metalurgy and Heattreating are the most critical aspects of blade making. You need to study some books on the subject. There are also some very good books available on the subject of knifemaking in general. Try Norm Larson or Centaur Forge

If you are rank beginner you need basic smithing and metalworking skills first. Check our "Getting Started" article at the top of this page.
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 15:18:29 GMT

Do you know anything about Armour used in the third Crusade?
Kay - Tuesday, 04/25/00 15:44:57 GMT

how do you make stainless damascus? I can't get the bilge to retain the heat. Me and another blacksmith have been trying, but it just won't work... thanks
Joshua Staley  <jstaley22 at hotmail.com> - Tuesday, 04/25/00 15:51:06 GMT

Dave, If you don't want to heat and punch the entire piece, you can "spot anneal" the point where you will drill the hole. Put a piece of round stock about the size of your drill bit into the drill, put it where you want your hole, and turn it on. Let the friction heat up the area you want to soften. Once it's red, let it cool slowly. Drill when it's cool enough to touch. -Eric
Eric Bramblett  <Eric_Bramblett at NOSPAM.yahoo.com> - Tuesday, 04/25/00 15:56:43 GMT


re: Rock Island

Do you suppose that the tags which have been mentioned before are inventory tags for tools and equipment that once belonged to the Rock Island Rail Road?

Remember, it was usually called the Rock Island Line.
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Tuesday, 04/25/00 16:25:54 GMT

For what it is worth,
I was reading a news report and came across this tidbit.

The latest asbestos discovery is the kind that digs deep in your lungs and
has already killed hundreds in a small Montana town, KOIN
reports. It comes from a mine that was the source of a revolutionary
gardening material that was sent all across the nation.

The deadly particle is called tremolite, and a lot of it comes from the
Libby mine in Montana. It already has a history of affecting a lot of
people there.

Libby is the extreme case, KOIN reports. The mine has been closed for a
decade, but not before the vermiculite ore, mined from Libby for
years, was sent around the nation in gardening products and as
insulation material by the W.R. Grace company. Vermiculite from that
mine contains the lung-damaging tremolite fibers.
Ralph  <ralphd at jps.net> - Tuesday, 04/25/00 16:34:35 GMT

Billet Heat: Joshua, Stainless is peculiar stuff. It has a high coeficient of thermal expansion but a low coeficient of thermal conductivity. I've always thought there might be a relationship there but it is one of those great unknowns.

Anyway, the point IS that it is easy to get a surface heat with stainless. If you are using a gas forge the problem is worse because gas forges heat rapidly and are hard to get a soaking heat without excessive scaling. Stainless is also "red hard" to a degree. It is harder to forge at a low red heat than it is cold!

Stainless reguires aproximately double the force to forge as mild steel at 2000°F but up to three times the force at 1600°F. You want to be careful not work over 2000°F because of micro structure problems that probagate between 2000°F and 2300°F

Weldability is also a problem and is addressed by many by using 5 to 10% flourite mixed into the regular borax flux. The flourine compound is aggressive enough to disolve chrome oxides where regular borax is not. The alternative is careful cleaning of billet constituants and heavy fluxing with borax to prevent oxidation in the first place. Flourine (related to chlorine), is very bad stuff but in general is only released in small quantities while used as flux. Good ventilation is a must.
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 16:56:11 GMT

Recently got some rusty dull files. Can they be "Damasced"
or do they contain to much alloy. If so, what do i layer with it?

Hazel  <ka_mom at hotmail.com> - Tuesday, 04/25/00 17:55:57 GMT

Files Hazel, generaly files are plain high carbon steel (1095). These can be laminated with mild steel or wrought, a nickle alloy steel for color or even pure nickle for high contrast. Grind all the teeth off first to prevent weld inclusions and remove forign materials.

I recycle the butt ends of files into short sculptor's riflers and special pattern making files. The handle end rarely gets worn out and may have a lot of use left. I gently heat the file then bend it to produce "spoon" files with a hemi-spherical surface from half rounds and curved riflers from round and triangular files. As soon as they are bent to shape I torch off the extra and quench. The ends are then dressed by grinding.

Rock Island: Paw-Paw, there is a whole series of businesses in Rock Island Illinois including Rock Island Arsenal. Just no vise manufacture. I've seen this brand and the logo is clearly cast into the vise.

The four old industrial catalogs I have dating 1898, 1928 and two from 1955 list Prentiss, Parker, Athol, Reed, Colombian and Dodge. I have a Reed & Prentiss so those two companies eventualy merged. Intrestingly all these catalogs had no-name brand blacksmith's vises. . .
- guru  <guru at anvilfire.com> - Tuesday, 04/25/00 18:18:48 GMT

Guru and PawPaw, Re: Rock Island, I really appreciate the research, I figured I'd have to make one. The tag that said Birtman Electric also said Rock Island Division, as if they had divisions in other cities. I might call some people named Birtman in the area and see what they know. Thanks again.
Randy  <rz at excelonline.com> - Tuesday, 04/25/00 18:26:03 GMT

Kay, third crusade armor: Lots and LOTS of chain-mail. Try the men-at-arms series (books, that is) or any book about the age of chivalry or medieval sculpture. The detailed grave-effigies from that era makes this kind of armor quite well-documented
Olle Andersson  <utgaardaolle at ebox.tninet.se> - Tuesday, 04/25/00 19:17:07 GMT

I have just made a knife out of a piece of car spring (coil) can I harden it using the magnet method? and once hardened what is the simplest way of tempering it, what temp should it be, etc. Any help would be appreciated.

I found this site a week ago, and consider it a goldmine of accesible knowledge, knowledge that I would find more difficult to obtain by other means as I live in New Zealand. Just my way of showing my appreciation. Dave.
Dave. - Wednesday, 04/26/00 00:15:18 GMT


Glad to welcome another Kiwi! You will also enjoy the Virtual hammerin, the iForge, and the Slack Tub Pub, all parts of the operation here at anvilfire!
Paw Paw Wilson  <pawpaw at paw-paws-forge.com> - Wednesday, 04/26/00 01:03:23 GMT

I've been blacksmithing for six years full time. Am setting up another forge in a location where I have to go through the wall to vent. Thinking of using 10 dia. pipe and two 45 degree elbows (a total span of about three and a half feet). Now what will work for the side draft? Everybody I ask has a different answer but they all say,
"Do it this way, I can't explain why these dimensions work but they do."
Well, I want to know what the relationship is between the size of the opening of the side draft and the volume of the space inside the side draft and the size of the pipe. I realize that the stack must be four plus feet above the peak of the roof and far enough away from the peak. That makes sense. Is it the SHAPE of the interior space of the side draft that matters or really just the volume and the size of the opening? A fourteen inch diameter pipe by, say three feet high would be cheap to locate at the scrap yard. Fabricating a side draft out of six plus pieces would be more expensive and take more time. But I want something that will work efficiently. And I need to have it set up yesterday..... Any answers???
Sandra  <sedunn at golden.net> - Wednesday, 04/26/00 02:15:10 GMT

Sidedraft: Sandra, I wish I had formula's and ratios to give you. These things have been being made by what "works" for cneturies. Here is the little I know.

A side draft works by creating a high velocity at the intake. This is what sucks the smoke sideways off the fire. The high velocity is created by having a small opening or pipe opening into a larger volume. On modern steel flues this is right at the forge level but on old brick flues it was higher. The higher position seems more logical however distance is critical. The greater the distance the lower the effect of the velocity on the smoke and hot air rising off the fire. A short hozizontal pipe or "mini hood" with radiused edges for smooth flow would improve efficiency. My feeling is that the area of restriction should be a little less than or equal to the flue stack cross section but not greater than.

The bigger the chambre that the flue opens into the better. A cross section of 2-3 times the flue and intake areas seems to work. In old flues and chimineys there was no smoke shelf, just a smooth taper, the intake restriction acting as the "smoke shelf". Modern steel sidedraft flues have a smoke shelf. I debate the stated logic of a smoke shelf. I believe that it acts as an open volume with a restricted intake which acts like a check valve. Down drafts and back drafts not being able to overcome the higher velocity as the air comes past the restriction. In the current commercial side draft units this is a redundant feature. We recently came from inspecting the brick flues at the reproduction Anderson Blacksmith shop in Williamsburg, Virginia. Those flues had a small sloping intake a foot above the firebed that opened into the bottom front of a pyramidal box that fed into the flue.

My only issue with your plan is the 10" stack. These work but are marginal. 12" should be used for a forge. However, one of our corespondants recently set up a 10" stack (I think) using one of those spherical turbines at the top and he says it works great. He has a tank or oil drum surrounding the forge, then a 16" culvert pipe for several feet and then the new stack. I'll forward the photos.
- guru  <guru at anvilfire.com> - Wednesday, 04/26/00 03:42:08 GMT

Other obsevations on forge flues: Big open hoods don't work. All the air at the opening of the hood (that includes all the COLD room air) has to move at the same slow velocity to the stack. This mixture results in overloading the stack and filling it with cold air which will not rise.
I've been explaining this to a friend of mine for years who has constantly had smokey shops even though he has gone to great effort to build big conical hoods using huge stacks. He observed the flues at Williamsburg with their little 10x10" openings (aprox) and was amazed at how well they worked. He would not admit they were exactly what I've been telling him for 15 years. "Small high velocity intakes work, big hoods do not."

Years ago Steve Kayne showed me his chiminey cap for a 10" flue. It was a typical conical rain cap but inside of it there was an upside down cone attached to the bigger rain cap to smoothly direct the smoke out of the stack. He said it prevented turbulance at the discharge which became a bottle neck. Made sense to me and it worked.
- guru  <guru at anvilfire.com> - Wednesday, 04/26/00 03:54:40 GMT

Last Word on flues: We have photos of the front and back of commercial side draft units in our ABANA edition of the NEWS. Look on the last pages. There is also a similar unit in operation shown in the AFC conference edition.
- guru  <guru at anvilfire.com> - Wednesday, 04/26/00 03:57:13 GMT

Tempering unknown steel: Dave, when you use scrap steel you have to become your own metalurgist. Take a scrap piece forge a section similar to your blade and experiment. Use a file or HSS cutter bit to judge the hardness. Try sharpening a short piece and see how it works. You have a choice of trial and error or purchasing a known steel.

The transformation point of steel is just a tad higher than the point at which it becomes non-magnetic. But by the time you've tested (in the forge) the part will have reached the tansformation point. Many alloy steels are oil quench and I start there. If it doesn't harden suficiently then try water (it should be warm or slightly above room temperature). You cannot judge temper temperatures of alloy steels by temper colors. The best way to get a uniform temper is to heat a larger block or slab of steel to a known temperature and then set your blade on that and let it soak up the heat. It should remain at tempering temperature for as long as you can maintain it or up to an hour. If your tempering block is fairly large just let it and the blade both cool together. Tempering temperature varies with the variety of steel. It can be as low as 350°F and as high as 1300°F. Most steels are tempered in the 500 to 600°F range. You really need to find a copy of MACHINERY'S HANDBOOK or one of the blacksmithing references such as Edge of the Anvil that has tempering data. If you are going to stay in the knife business you should purchase one of the (relatively expensive) references such as the ASM Metals Reference Book. There are just too many steels and too many combinations of treatments to cover here.
- guru  <guru at anvilfire.com> - Wednesday, 04/26/00 04:13:29 GMT

Dear Guru
Many thanks for your advice re a forge for the Indian Ocean. There is charcoal available and so he is likely to start with that. I copied the plans for the beginners forge and for the anvil - great stuff. You have a very helpful site here. I'll visit again
David Crowson  <david.crowson at mencap.org.uk> - Wednesday, 04/26/00 09:19:03 GMT

Hadfild and Sanderson anvil. The weight is marked in the English Hundred weight. Thanks John Thomas Mott
John Thomas Mott  <Anvilstriker at mindspring.com> - Wednesday, 04/26/00 11:53:59 GMT

Guru:induktion furnace again, I kan get 44 kilowatts out of my system, would that be too little to get my 10x10x10 centimeter steelblock to welding heat? by induction?
If not, how much would I need.
would there happen something funny if I put inn 1x1x10 centimeter steel, like would it vaporize or wouldnt it work because the oven has to fit the object to be varmed?
always while assuming that my pockets are deep enaugh
Stefan  <stefan at imv.uit.no> - Wednesday, 04/26/00 12:27:50 GMT

OK OK OK: Stephan, I'll look up the KW requirements for induction furnaces.

In the RESISTANCE kiln I mentioned the part would not vaporize but would heat at the same rate as the kiln. However, there ARE resistance heaters for steel where the work piece is part of the circuit. Like a fuse, too small a piece WOULD vaporize! Now induction furnaces are a completely different animal. The material heated is the magnetic core of the furnace. I'm not sure what happens when there is insuficient material.

Melting furnaces are rated in tons. Converting the kw/ton to kw/pound we get 60-100 Watts per pound. Your 10cm x 10cm x 10cm (3.94" x 3.94" x 3.94") block weighs 17.3 pounds (7.85 kg). Approximately 1300 Watts. However, the power neccessary is dependant largly on energy loss which is much greater in a small furnace than a large one. Use a factor of 8 for a small shop furnace (10Kw). Melting furnaces are also designed for slow heating and holding the heat (much like a kiln). For fast heats you need to multiply again. Say another 4x (40Kw)

There are two types of induction furnace, line frequency (50-60 htz) and high frequency. In line frequency furnaces copper tubes are used as conductors with water cooling. In high frequency furnaces a water jacket is used. Typical voltage is 6000 V. 3PH current must be converted to single phase via a phase balance and automatic power factor control. For capacitys of 1000 pounds or less line frequency is not satifactory and it is necessary to to increase the frequency to 180 or 540 htz. High frequency increases the Kw drawn by the multiple of the frequency. A small furnace is going to need the highest multiplier and this raises the Kw needed to 360.

I am probably wrong on the multipliers so lets guess 100Kw. AND a properly sized (to the job) furnace. Having built resistance furnaces and infrared furnaces I'll guess this is a $50K unit (+/-$15K) IF its is not specialy engineered and $100K (+/-30K) if it is a special.

In the end, the resistance heater I mentioned is MUCH more economical. Its just like sticking a welding rod. Ever get one stuck and see the whole thing turn red and go limp? A BIG low voltage transformer and a couple electrodes. Clamp the piece for a few seconds and its HOT. The limitation as always is energy and the capacity of the device delivering it. At the end of the great rivited construction era electric rivit "forges" were produced. The worker held the rivit in a pair of tongs, rested it on a copper pad, pressed a foot pedal that clamped another copper pad to the top of the rivit. A moment later, you have a hot rivit without the problems of heating in a conventional forge.
- guru  <guru at anvilfire.com> - Wednesday, 04/26/00 17:02:51 GMT

This is the number for NC Tools the manufacture of the whisper momma forge, 1-800-446-6498. I recently bought the model-3 whisper momma with end ports. I have nothing but praise for the folks who answer their phone. They have been able to answer all of the weird questions that I had.
Skip Davis  <skdavis4 at juno.com> - Wednesday, 04/26/00 17:55:35 GMT

Side draft and Chimney effect: Sandra, to add to what the guru has said... Draft in a chimney or flue is determined by the difference in density of the hotter flue gas at the top of the stack compared to the ambient air. This creates a pressure differential that causes the gasses to move up the stack. This is why a cold flue will not draw, there is no pressure differential to drive it. The pressure differential drives the velocity of the gas up the flue, but some of the pressure differential is "used up" in overcoming friction of the gasses in the stack and flue. So to make the stack work as well as possible, minimize the restrictions to flow. Few or no elbows, larger stack diameter, etc. The biggest restriction will be the opening to the forge. You need adequate velocity through that opening to "capture" the smoke off the fire. But creating this velocity takes some of that stack energy. The whole thing can be engineered, but there are many factors, some of which you mention, but you don't provide enough information to do the engineering. And I can't take the time, sorry. The large chamber after the flue opening reduces the pressure drop, so it helps. But don't make it so big that the gasses cool off or there will be no change in density that creates the differential pressure. I hope this explains some of the concepts and guidelines.

Marks Handbook has some information on chimney design. I use a book called Industrial Ventilation by the American Conference of Governmental Industrial Hygienists for hood and duct design. A library should have a copy.

Forget about smoke shelves. They only add restriction.

A "low loss" stack extension works best. It is basically a larger diameter section of stack, 6 times the stack diameter long, on top of the stack where the cap would normally go. No cap is necessary unless there is absolutely NO wind. Any rain that hits the inside of the stack extension runs down the inside of the stack extension, but drops between the gap formed by the stack and the larger diameter stack extension. Hope this is clear.

Induction: Stefan, you seem fixated by induction. Did you know that the major induction furnace maufacturers are working on levitation melting? Very cool. No furnace shell required. I've seen it done with aluminum. When it's melted off of the pedestal, the metal flows with the induction lines of force and is contained by the induction forces. Did I say very cool? Furnace shell and refractory maintenance are some of the highest costs in induction melting. I can tell you that a 35 ton line frequency iron melter takes 9 megawatts of power. But as the guru said, small furnaces have MUCH higher losses.

For a small melter,I suggest you find a friendly electrical engineering student or instructor at some university and ask them to help you. Maybe you will find a kindred spirit. Pillar, ABB, Junker (pronounce it "yunker" or the Germans will be mad at you) and Inductotherm are the bigger induction melter companies. Oh, and don't try to keep up with the Junker boys at drinking Trappist Monk beer if you happen to get to West Germany. They are much better at it than I was.

Have fun.
Tony  <tca_b at milwpc.com> - Wednesday, 04/26/00 19:49:17 GMT

Induction again: Stefan, you have me hooked on induction again this afternoon. (grin) I looked up some of my old info. Mark's handbook has some good info also and it agrees with my Inductotherm stuff. I get 350 watt/hours per pound and 9600 hz for a furnace to melt less than 50 pounds. Not including losses which would probably come close to triple the power. Then the frequency multiplier and I don't have info on that to go to 9600 hz. The frequency is tightly related to the size of the melt. Power factor correction is a must also or the power company and/or your neighbors will get real excited.

Well, that was fun. Send pictures when you get it built. You're gonna need a lot of copper, rectifier and capacitors. As I mentioned, my experience is with 35 ton line frequency induction melters. We had 5 of them, but one was always down for reline. I can't describe how it feels to be standing 20 feet away from 36 megawatts of hunka hunka burning POWER! The whole melt deck vibrated and hummed. And seeing 35 tons just stirring away in the pot like a witches brew. Ooo, it just makes me shiver.

BTW, we preheated with natural gas to 1250 degrees to increase efficiency and throughput. That was paying 1.8 cents per kWh. If we had to pay market prices which were about 5.5 cents per kWh, we would have preheated as far as we could with gas. On a small scale like you are discussing, it WOULD be MUCH more efficient to use any other method to get to welding heat. But hey, I never said I do everything the most efficent way either. There's that "Gotta Pay to Play" thing again. Hee Hee.
Tony  <tca_b at milwpc.com> - Wednesday, 04/26/00 20:50:06 GMT

- guru  <guru at anvilfire.com> - Wednesday, 04/26/00 21:07:26 GMT

Gurus, Guruinies, guruettes: This might not be the proper forum, but here goes. I am hearing rumors that the Northwest Blacksmiths Associations Spring Conference, scheduled for May 5-7 in Oakland Oregon has been posponed a week! Is this true, does anybody know, I have emailed the prez and sec but no answer (yet). I would be PO'ed to haul a ton of tailgate treasure over the mountains and thru the woods to find out I was out of synch. WADAYA Know?????
TIM - Thursday, 04/27/00 00:56:59 GMT

Skill Level:beginner
emphasis: mild steel home furnishings, mig welded
Question: Are there any recommended finishing techniques to achieve a look similar to wrought iron (acid dipping?, mild heat and oil dipping?) Thanks in advance
Mark  <mark.pauster at timet.com> - Thursday, 04/27/00 02:19:16 GMT

Skill Level:beginner
emphasis: mild steel home furnishings, mig welded
Question: Are there any recommended finishing techniques to achieve a look similar to wrought iron (acid dipping?, mild heat and oil dipping?) Thanks in advance
Mark  <mark.pauster at timet.com> - Thursday, 04/27/00 02:20:34 GMT

hello guru and all,
I need a scoource for wrought iron in the North Texas area. If there isn't one in his area that you know of then please direct me to how i can find some.

Also...is ther a Tool Steel that contains nickel? if so what is it? if not what is also just as bright?

Thanks in Advance,
Scotsman  <albagobragh99 at yahoo.com> - Thursday, 04/27/00 02:46:08 GMT

Help! I am a newbie and just first fired my home built forge yesterday. I have spent a half day with a kindly blacksmith who got me started. The questions that I have are,
Where can I find items such as large ball bearings or cast iron balls and other items? My metal scrap dealer only has plate, square and round stock.

Also, what would you recommend for cutting steel of 1/4" or thicker? I currently only have a hacksaw and do not know which to look for whether a torch, plasma cutter or reciprocating saw.
Thanks for the help,
Alan Myers  <myersfamily at worldspy.net> - Thursday, 04/27/00 03:00:18 GMT

What kind of electric power is going to be available for JYH at Flagstaff? 110? 220? 3PH?
mark  <kbmk13 at prodigy.net> - Thursday, 04/27/00 04:00:39 GMT

Tim, Yes the Deal at Oakland is now the following week.

Mark, what look? Freshly forged wrought iron does not look different than mild steel. But if you are talking old rusted looking pieces, then you can use vinager, or a mild acid, or bury the pieces in horse dung...... It will then have a nice rust finish.

Alan, cast iron balls would not be forgeable. And why ball bearings? The round and square stock from the scrap yard dealer would be more usedfull for making items out of. Unless you are more into making blades etc
Ralph  <ralphd at jps.net> - Thursday, 04/27/00 05:20:41 GMT

I know of a new militray surplus acytelene generator
I started looking round for calcium carbide. Looks as though our leaders have put such legislation out there that shipping calcium carbide far exceeds the value of the product. Need some input as to a reasonable source of calcium carbide. Feel that the generators were a common item in most all the blacksmith and early machine shops
RJ"Bob"Evenson  <rje at lightening-isp.com> - Thursday, 04/27/00 07:05:03 GMT

Regarding carbide (calcium carbide, CaC2)
After you add water and produce acetylene gas, you are left with a gunky residue which is a mess to clean out and consists of calcium hydroxide, which is a strong base. Defintely not something you want to dump in your back yard, flush into the sewer, or otherwise introduce into the environment.
Neal Bullington  <NRobertB at aol.com> - Thursday, 04/27/00 12:19:26 GMT

Acetylene: Bob, you are one gutsy guy if you want to generate your own acetylene. We did that in a plant that used Lots of acetylene and the demand was fairly constant. But about every 10 years, the acetylene shed blew up. We had dedicated operators and automated pressure controls, but still, something always seemed to go wrong occasionally and the pressure would go high and Boom! I think the operators job was so boring, the guys probably fell asleep and didn't see the pressure rising. The pressure controls consisted of a counterweight arrangement that controlled how much calcium carbide was dipped under water. The counterweight was balanced by the pressure of the acetylene gas. Usually what happened is the counterweight linkage would bind up and the carbide wouldn't get raised back out of the water when the demand for acetylene dropped. So the pressure would go high. How does the military surplus one work? I don't work there anymore, but if you run to a dead end, I can call and ask where they get their calcium carbide. It came in sealed 55 gallon metal drums. I know that they won't sell you any, but I might get their source.

Nubian Slaves: I was doing some reading this morning and ran across the following statement in a book on manufacturing processes. "A portion of the process of making the famous Damascus blades was the plunging of the blade through the belly of a Nubian slave after it had been heated to the color of the rising sun as observed from a certain location in the desert". Any truth to that? Glad my ancestors weren't Nubian! I suppose that would be a fairly constant set of parameters though. Without pollution, the sun color should be about the same every clear day and the nubian slaves would always be a consistent temperature.....
Tony  <tca_b at milwpc.com> - Thursday, 04/27/00 12:48:00 GMT

The slave quench is an old wives tale. The human body varries too much in density to make a good quench. The same has been said about the samori blades, etc.
Wayne Parris  <benthar at pacbell.net> - Thursday, 04/27/00 13:29:58 GMT

Body quench: Dang, Wayne! I was hoping there was another good use for all of those lawyers we were talking about testing swords on! But you're probably right. I've seen some real fat, bloated lawyers and some skinny little anemic ones. Mostly, the fat bloated kind though.
Tony  <tca_b at milwpc.com> - Thursday, 04/27/00 14:04:39 GMT

Human Quench: Yep. This is a boogyman story. Probably the worlds second oldest lie and used to scare little children or told to some fair maid in hopes of geting her favors. . . Now replaced by "the check is in the mail" or "my uncle is a Hollywood producer." ;)

Artisans tell the ignorant who WON'T LISTEN all kinds of stories just to get them to go away. How do you think the story of the "varnish" is what makes a Stradivarius violin so great started? I'm sure some dilitant that didn't know the working end of a chisle or oak from pine was pestering the master and he said. "Its the secret varnish". So for 200 years idiots have been putting together hack violins that they are sure their recipe will make into a masterpiece. And YES it has been published numerous times in various books. . . No one wants to hear that it takes a lifetime of dedication, training and study to get that good.
- guru  <guru at anvilfire.com> - Thursday, 04/27/00 14:16:27 GMT

Acetylene Generators: These were replaced by today's safety cylinders in the 1930's and had been in the process of being replaced since about 1910. The old generators were very dangerous. My grandfather's shop had one and from the stories my father tells I'm glad mine does not!

Acetylene is an unstable gas that disassociates explosively under pressure or shock. To avoid this, acetylene cylinders are filled with porous pumice stone to prevent shock wave probagation and then filled with acetone into which the gas is disolved. There is almost no free gas in an acetylene cylinder. The cylinders also have meltable pressure release "fuses". The fluid fill is also why you NEVER, EVER use an actylene cylinder on its side.

This and many other safety related aspects of welding are why I urge everyone to take a trade school or college welding course. Learned on the job? You need the course more than the rank amatuers!

Knowledge is your most important tool.
- guru  <guru at anvilfire.com> - Thursday, 04/27/00 14:34:14 GMT

Im starting out, about to build my first forge. I live in california and coal is not so readily available as i wish. So, im wondering if i should build coal or propane forge using plans off anvilfire.com. the coal forge seems much safer, also wondering if anyone uses a propane burner like this one, or have built this one here.
abraxxus  <caleb at realgoods.com> - Thursday, 04/27/00 14:51:00 GMT

what instuments do you need to start a forge from scratch?
Cole Finley  <ireland_01 at hotmail.com> - Thursday, 04/27/00 16:25:32 GMT

Cole I have found that bagpipes work best for me! GRIN!
I will assume you mean a coal forge. An automobile brake drum and some pipe legs and a hairdrier and some dryer(clothes) vent tube can get you going.
The guru has a "Getting Started" section and a section with pic or sometimes plans on various aspects of tooling(forge etc) It can be reached from the home page area of this web site
Ralph  <ralphd at jps.net> - Thursday, 04/27/00 16:42:37 GMT

Interesting aside (at least to me) is that old coal mining lamps burned acetylene generated from calcium carbide. Got to wonder what kind of accidents happened there, especially with the whole contraption strapped to your head.
jdickson  <TheIrony at worldnet.att.net> - Thursday, 04/27/00 16:57:39 GMT

Forges: Abraxxus, Contact the CBA (California Blacksmiths Association) about sources of coal. ABANA Chapters often purchase coal in quantity to reduce shipping costs and price/ton.

Safety of most gas appliances is up to the user. The biggest danger is gas leaks and flame outs. Gas forges MUST be attended. Many locations (all schools) require flame out sensors to shut the forge down. All gas fittings and connections must be tested for leaks under pressure with a soap water solution (see comments above and in "Getting Started" about taking a welding class).

I've built two forges and one furnace with the simple gas burner (also took part in building the famous 10 minute gas forge). The furnace and my forge have relatively sophisticated ingnition and control systems. However they all have the same inherent dangers. As mentioned thousands of commercial forges used the same system. New forges are slightly more sophisticated, but not by much.

In general coal forges are safer. However, they make a lot of smoke (how close are your neighbors), availability of good coal is an problem for many, and fire IS fire. Spilled coals, fly ash OR hot scale from iron will set dry grass on fire. I've found myself standing in a grass fire on a number of occasions! This is no joking matter in California. Always keep a (full) water bucket handy. More important, treat fire with the respect it deserves.
- guru  <guru at anvilfire.com> - Thursday, 04/27/00 17:11:42 GMT

More on carbide:
As one who has used antique carbide miners lamps for 40 years for cave exploration, I have always thought that they were perfectly safe if you understand how they work, which is pretty simple. The only accidents or incidents I have encountered with them was when the wearer wasn't paying attention to where he pointed the flame from his cap lamp. While climbing a rope, for instance, or closely following another caver thruough a crawlway.
NRobertBullington  <NRobertB at aol.com> - Thursday, 04/27/00 18:04:14 GMT

TIM and others!!!!!!

YES! the N.W.B.A. conference dates were mis-printed in the winter issue! The correct dates are May 12,13,14!!!!!! Sure glad I'm not on the board anymore. Major blunder. Website has correct dates anyway.
grant  <nakedanvil at usa.net> - Thursday, 04/27/00 18:53:02 GMT

I am looking for info on finishing on the work that I have done? Does anyone have any links or info that would help me out. Thanks Ross
Ross  <ross_m at direct.ca> - Friday, 04/28/00 02:47:12 GMT

Finishing: Ross, I avoid "natural" oil and wax finishes except for temporary use. See my article on Corosion and its Prevention on the 21st century page.
- guru  <guru at anvilfire.com> - Friday, 04/28/00 03:10:46 GMT

RE acet generators. I have had and run a couple of old ones years ago when I was poor and going thru a lot of acet. One of them came on a 3 wheeled cart with a mounting clamp for a oxy tank. Generally I was fixing one while the other was working or both were down...but it sure was cheap gas. The other amusement that comes with them is breaking down your regulator and cleaning it out real often. After a while it ceased to be amusing but i got quicker. The gas came through the line with a gunk bonus . I kept them out in the "breeze" (it howled there) so the incidental leakage wasnt much problem. and there was no problem finding something to neutralize acid.
An old welder who used one for a long time (before they found out how to store acet in a bottle full of aesbestos and acetone) said....that the most common reason that they blew, was guys got lazy and just kept adding more carbide when gas production dropped instead of cleaning it out when the charge ran out. He said that when enough sludge built up in the generator that the mass would "start regenerating" and run up an overpressure.
I used to buy mine from Union Carbide via a welding supply
Pete Fels  <ironyworks at yahoo.com> - Friday, 04/28/00 05:01:05 GMT

I'm trying to carve into granite with a chisel made from a truck spring hardened and powered by an air hammer,you guessed it I didn't get far with it. It sort of got dull and also broke. It my have some thing to do with my inexperience. If I try again what grade of steel would you recommend for a chisel that I could forge myself with some knowledge. thank you .
heinz  <hlzach at prcn.org> - Friday, 04/28/00 05:22:47 GMT

Acetylene Generator: Thanks for the first hand knowledge Pete!

Now if you are a REAL die hard the Calcium Carbide is made by burning coke and seashells together. I'm not sure of the actual conditions but it has a very long history. What's interesting is that seashells were commonly used as a flux in the charcoal iron producing days.
- guru  <guru at anvilfire.com> - Friday, 04/28/00 13:00:31 GMT

Where in Ca. are you? I am in CBA and ABANA and I teach basic blacksmithing in San Diego. email me and we will get you hooked up :-)
Wayne Parris  <benthar at pacbell.net> - Friday, 04/28/00 14:00:08 GMT

Stone Chisles: Heinz, Stone hammers are made from both plain carbon steels like SAE 1095 and high alloy steels like shock resistant S-7 or W-1. In all cases proper heat treating is critical. MACHINERY'S HANDBOOK reccomends a hardness of Rockwell 46-48 (much less than full hard).

All tool steels require special handling when forging. Alloy steels are most critical. Tool steels should be thoroughly warmed before heating in a forge. Forging temperature and heating times must be limited (long soaks at temperature ate bad for the steel. Overheated alloy steels fall apart when forged. Each steel has its own hardening/tempering parameters. The steels listed above range from water quench to air quench.

If your chisle broke you probably didn't temper it or had an uneven hardening. When impact tools are overhard they also wear rapidly by chipping of the edges. Springs are made of a great variety of steels and when using scrap or unknown steels YOU must become your own metalurgist. Spark tests, trial and error hardening and tempering, hardness and ductility testing with comparisons to known steels. You will rapidly find there are no pat answers to using "recycled steels".
- guru  <guru at anvilfire.com> - Friday, 04/28/00 14:43:22 GMT

How can I repair a chip out of an anvil top. Thanks,debbie
debbie  <demcaul at hotmail.com> - Friday, 04/28/00 14:45:36 GMT

Anvil Repair: Debbie, It depends on the type of anvil but in general the methods are the same. My first reccomendation is to ignore it and work around it. Good anvils are hardened tool steel and you are very likely to do more damage if not very careful. Cheap anvils are made of castiron and not worth the effort.

Grind out the chipped area until no temper lines around cracks are observed. Preheat the anvil to about 450°F and weld with a high manganese rod designed for tool steel repairs (ask your welding supplier). Peen between passes or when finished the the weld is cooling. Grind flush when finished. If the chip was on a sharp corner the corner should be gently radiused.
- guru  <guru at anvilfire.com> - Friday, 04/28/00 18:08:51 GMT

okay..here's a question for mainly grandpa but the great guru might be able to asnwer it as well:
i have heard both that the higher the carbon content the brighter the steel and the reverse of that. I am questioning as to which is true..this is mainly about carbon steels of course as the additive of other elements into steel would be a large deciding factor i believe. but i hope that the carbon content is the main deciding factor...if that is even true.
So, which is true?

Thanks in advance,
Scotsman  <albagobragh99 at yahoo.com> - Saturday, 04/29/00 01:01:09 GMT

Guru, After pricing a few large air-compressors I decided to try to put together one for myself out of salvaged parts. I located a 60 gal. compressor w/o a motor, an 80 gal. vertical tank ( needs cleaned up but otherwise in good condition, I think)with no motor, a 10HP three phase motor, and a compressor that came off of a 400 gal. tank which appears to be BIG enough. Also purchased a 5HP motor with compressor. I am going to connect in series and use the 10 HP to run the large compressor and have the 5HP as a backup. All for under $400! Not bad considering new equipment would have run in the thousands! Question: how do I know if these old tanks are safe? Fill and hope they don't blow me into the next county? Is there a way to statically test a compressor tank? Thanks in advance. TC
Tim Cisneros  <blacksmith at starsticker.com> - Saturday, 04/29/00 02:35:11 GMT

Question for Grandpa: I have some fairly large (for this young landlubber, at least) steel cable on our place that is about to be hauled off to Erath Recycling. In some parts it is rusted to the point of disintegrating, but in other places it is just the standard cosmetic rust iron gets. Should I save some of the good stuff for future use in cable pattern-welded steel? Or is it easier to buy new cable without rust?
Stormcrow  <mbhelm at cctc.net> - Saturday, 04/29/00 02:54:21 GMT

Air Tanks: Tim. That is a touchy subject in certain parts of the country. One state had every air compressor tank (generaly with compressors) that was over 5 years old scraped! This was based on their state OSHA department defining air tanks as pressure vessels (under their jurisdiction) and the difficulty of inspecting them.

Inspection is done visualy with a bore scope or mini camera from the inside. Testing is done water filled. A tank without air, just pressurized water, cannot explode. Water, being an incompressable liquid does not store energy. Therefore if the tank ruptures there is no energy behind the failure and all you get is a big leak and the pressure instantly drops to zero. Inspection and testing must be done by a licensed inspector in most states.

It is very important that the tank have a working pressure release set just a little above the working pressure AND of sufficient capacity to discharge ALL the air that the compressors can produce.

My experiance with air tank failures is pin hole leaks from rust that start as a minor nusiance and then become unacceptable. I'm sure there are a ton of safety rules. . . The tanks SHOULD have the OEM pressure rating tag. Generaly this is 200-300 PSI or so. You should be running much less. 120-140 PSI. Most air tools and similar devices are rated at 90 to 100 PSI (most air hammers too). Just be sure to run big enough air lines that pressure drop is not a big issue.
- guru  <guru at anvilfire.com> - Saturday, 04/29/00 04:29:17 GMT

Steel Colors: Scotsman, I cannot distinguish a color difference between wrought iron, mild steel and high carbon steel finished in the same manner. Machined, buffed and polished, they all look the same. However, HARD parts often have a different look (and feel) to them.

Alloy steels vary significantly from no apparent difference to the yellow blush of stainless (from the nickle). Chrome steels look slightly bluer. For most it is very hard to tell even in good light while side by side.

The difference occurs when etched. High carbon steels are more susceptible to etching than low carbon steels (someone please correct me if I'm wrong). Alloy steels are generaly more etch resistant.
- guru  <guru at anvilfire.com> - Saturday, 04/29/00 04:47:00 GMT

Scotsman: Different acids (etchants) react differently to any alloy content in steel. Also, the crystal structure in steel will affect the action of an acid. Pearlite etches differently than martensite, etc.
Stotmcrow: Light rust is "OK". Won't cause a problem. New cable costs money(generally).
grandpa  <darylmeier at aol.com> - Saturday, 04/29/00 05:12:46 GMT

Thank you for you reply on my stone chisle steel . You are very helpfull.Looking forward to send you another question soon.Have a great day.
Heinz  <hlzach at prcn.org> - Saturday, 04/29/00 05:46:29 GMT

Thank You both...now my mind can rest..:)
Scotsman  <albagobragh99 at yahoo.com> - Saturday, 04/29/00 13:23:08 GMT

I was recently having a disuccion with someone about the financial security of a blacksmith. this person said that blacksmith's don't earn more than $25,000 a year. I know finaces are a taboo topic, but I was wondering how accurate this belief was. I would appreciate any light that may be shed on this subject

Patrick Bjerke
Patrick Bjerke  <colossus101 at yahoo.com> - Saturday, 04/29/00 21:59:43 GMT

Income: Patrick, There are blacksmiths and then there are blacksmiths. In the US almost 100% of all smiths are self imployed so actual income numbers are hard to obtain. Many are also playing the starving artist game. Others are doing the "craft circuit" routine (full and part time). These two groups typicaly don't make a lot of money and have to be in it because they love the craft. I would guess that less than 1% of the artist-blacksmiths make a really good living. I never made an annual profit when I was doing the craft show routine but I've made 10K a month (out of a 24K gross) doing industrial smithing/ironwork jobs. If there were a steady market for it localy I would still be in it.

A small time industrial smith can make 50 to 100K year. Those with employees producing product or sharpening bits can make more. Fabricators working alone make roughly the same. Those with employees make more. Employees of industrial shops get paid fairly well. It is heavy hard and dangerous work.

Most of the smiths I know (including myself) are tool-aholics. If we have any serious income it goes into a variety of tools and equipment and doesn't show up as income (even though it is). To setup an industrial smithy with heavy forging machinery and all the periferial support equipment (truck, fork lift, saws, cranes) is expensive and will often absorb many years of income. Often the profit doesn't come until one goes out of business and sells off a lifetime collection of tools and equipment.

In any self-employment situation there is almost NO financial security unless you make it yourself.
- guru  <guru at anvilfire.com> - Sunday, 04/30/00 01:24:57 GMT

Guru, Thanks for the info. I am going to have the tanks tested by a professional. Even if it costs $100/ tank I've still saved a bunch of money. Not to mention peace of mind. If they are no good I've saved myself or someone else from injury or worse, chock it up to experience and buy a tank from Graingers. TC
Tim Cisneros  <blacksmith at starsticker.com> - Sunday, 04/30/00 02:59:40 GMT

Hello !
My father was a smith and I was raised in his shop and went on to welding school. My question is what is the RPM of a 25 lb.Little Giant Trip Hammer? I can remember hearing Dad pounding out plowlays when I was a kid but a friend bought a
trip hammer and he needs to know the recommended RPM. It
used to be on a line shaft and now he wants to put an electric motor on it. Thanks! Terry
Terry Lich  <tlich at ncfcomm.com> - Sunday, 04/30/00 14:56:40 GMT

Little Giant: Terry, We have a specs chart listed on our Power hammer Page. It is from their 1976 specs. At that time they stated 437 but in 1928 and 1955 listings (slightly different machine in '28) they stated 375 RPM. I've always stated that Little Giant over rated their machines, there is the change. I'll have to put the compartive literature on the chart.
- guru  <guru at anvilfire.com> - Sunday, 04/30/00 15:29:15 GMT

Air Tanks: Tim, I've always been surprised at how economical new tanks are. Lately I've come to appreciate screw compressors which are rated at 100% duty cycle and do not have a storage tank or a 'reciever' (they have a small oil-seperation tank).
- guru  <guru at anvilfire.com> - Sunday, 04/30/00 15:35:43 GMT


Just an FYI: I have nine employees and no one made less than 40K last year. There was a time when we had 15 employees. Now we do twice the business, go figure! I prefer to have fewer skilled, well payed employees who need little or no supervision, quite the opposite of most modern industry. We do industial forging and manufacturing. Wages are close to the high side of the middle range around here, not the highest, not the lowest.
grant  <nakedanvil at usa.net> - Sunday, 04/30/00 19:57:54 GMT

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