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 May 1 - 7, 2009 on the Guru's Den
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Anvils' popularity.
I started iron bending in 1963 in a horseshoeing situation. Most hot-shoers owned or were looking for a farriers' pattern Hay-Budden. My first anvil was a 158# HB, which I hauled around in my rig. At the craft center workshops, I saw more HB's and Trentons than any other American brands. I then began to see more English Peter Wrights and Mouse Holes (sometimes it said Morse Hole on the side). I would guess that these old brands outnumbered most of the other brands that I saw in the 60's and 70's.

I still trust these anvils. I have a few HB's and two Trentons for my school. I have an M&H Armitage. I own two antique anvils which I don't use, the latter being one English and one Spanish.

I tend to think of the HB's and Trentons as Cadillacs and Lincolns. As for PW's and Mouseholes, both I liken to
Rolls Royce.
   Frank Turley - Friday, 05/01/09 13:22:36 EDT

More anvil qualities. . AIA includes quite a few imported anvils but only those that were commercially imported. However, there are many old anvils floating around that are European made, many without names, many slightly different looking but mostly very good since they were brought here as personal tools by immigrating blacksmiths.

How do you evaluate such anvils? By shape and texture. Even if you have not seen one before most of these anvils were hand forged using sledges which leave distinctive marks or texture. Shapes are not what we are used to in North America but are graceful and well proportioned. Plate lines may show or not but steel corrodes differently than wrought.

If you can recognize one of these as a quality anvil then any branded anvils should be as easy.

This should do unless you are looking for "name" collector's pieces. We have far too many collectors that only want "name" anvils with sharp corners no matter how they got that way.
   - guru - Friday, 05/01/09 13:55:42 EDT

I'd like to know how to harden steel after you have taken soft metal and worked it? Or the best way to harden steel or whatever???
   Verald B. - Friday, 05/01/09 17:30:07 EDT

Verald, I could help you if I understood your question. Is the soft metal you worked a hardenable grade of steel? High carbon, medium carbon, am I ringing any bells here? Help me understand what you want.
   quenchcrack - Friday, 05/01/09 18:27:29 EDT

Lead is a soft metal... can it be hardened?
   - Nippulini - Friday, 05/01/09 18:49:57 EDT

Greetings all- A thread on another forum has me seriously thinking about building a self contained air hammer. A post on said thread put me onto a Google patent search for patent# 707246 which is for a 1902 Massey hammer. Cool stuff.

After reading the patent (quite dense language) and re-reading the pages on the home built self contained hammer here I have a few questions. As no one in my area has a hammer that I can measure the cylinders on, does anyone know if there is a typical cubic inch of displacement per pound of tup weight? Or to put it another way, what size are the cylinders on something like a Nazel 1b or 2b?

Also, machining larger parts shouldn't be an issue but it'd be nice to know how to tolerance them. Should I assume that hammer cylinders and pistons should have similar clearances to those found in air compressors?

I should have been an engineer like my Grampy, then I wouldn't need to pester you all with questions. Thanks in advance to everyone, especially Jock who has the best smithing site on the net.
   Judson Yaggy - Friday, 05/01/09 20:05:01 EDT

Hardening "Metal": Verald, From the form of your question I can tell you have a LONG way to go. So briefly.

1) Few metals are hardenable to a great extent.
2) Steel is the most commonly hardened metal.
3) Steel is a mixture of iron and a small amount of carbon.
4) The more carbon in steel the more hardenable it is to a point. Too much carbon weakens the mixture and the result is no longer maleable. At that point it is "cast iron". Too little carbon and steel is not hardenable enough to be useful for edge tools or cutting tools.

5) Steel is hardened by heating to the "transformation point" which is also a little above the temperature at which it becomes non-magnetic, THEN rapidly cooling the steel (quenching in brine, water, oil, air). The cooling rate is determined by the type of steel.

After hardening steel should be tempered. That is reheated to a point between 350 and 700°F to reduce brittleness. Steel is often annealed prior to hardening. To anneal the steel must be heated to slightly above the hardening point then cooled very slowly. This cooling is often done in an insulating medium like wood ashes, lime or vermiculite. However, some steels must be annealed by cooling VERY slowly and this requires special methods.

The rules are fairly simple for what are called "carbon steels". These are steels without a lot of alloying additions (nickle, chrome, manganese. . .). With alloy steels you need to know the steel, know the processes, do the research.

Note that as carbon and alloying increases in steels they are much les "soft" at forging temperature. So "soft" can be a very relative term.
   - guru - Friday, 05/01/09 21:09:05 EDT

Self contained hammers:. . . somewhere. . . I have copies of many of the Chinese hammer specs and a table of force and mass calculations from Nazel. I also have an old hard bound Chambersburg catalog from back in the 40's that has a LOT of dimensional information (but no tolerances). AND THEN, there is the tilting compressor cylinder (one of my ideas).

Like to spend a week here scanning documents?

In self contained hammers there is no storage of compressed air and no sustained "compression". The air is a flexible link between the two cylinders. As one goes down the other goes UP. Air is taken in AND exhausted with every stroke. Without air exchange the hammer would rapidly heat the air to where the slightest bit of oil would result in dieseling. Air is also taken in to keep the volumetric balance between the cylinders otherwise air would be continually lost until the free cylinder would no longer move.

Motion is caused by vacuum as much as by pressure. While there is no significant limit on pressure, vacuumm is limited to atmospheric pressure (14.7 PSI) and in a half filled system the limit would be about half of that. SO, cylinder area must be mass divided by less than 1/2 atmospheric pressure (adjusted by the ratio of the cylinders and offset by a K factor). The lower the necessary pressure the quicker the hammer responds (short "pump up" time). All this probably equates to some range of a constant multiplier.

Nazel hammers had a large snubber built into the driven cylinder cap. This part fit into a snug fitting bushing in the piston and acted like a shock absorber. Some say this gave the Nazel a much smoother easier to control operation than the Chambersburgs.

Chambersburgs also had a weak piece of design that commonly fails. That is the gear reducer in the middle of the drive train. They did this to avoid expensive low RPM motors which must be custom made.

Nazel exhausted their air out a stack pipe. Chambersburg exhausted air back into the frame of the machine. This recycled lubricating oil AND air. The Cburg would run hotter but did not need an exhaust pipe or oil collector on the end of the pipe.

Tolerances of large cylinders, ring sealing and such are all subjects of Machinery's Handbook, Marks' Mechanical Engineers' Handbook, and ASTE Tool Engineer's Handbook to mention a few. However, they are also guide fits for the ram. This is balanced by the fact that resiliant seals help support the load.

Note that patents are written to hide and obscure anything not part of the subject of the patent. Drawings are never to scale and specifics (such as tolerances) are never given or even alluded to. The goal of the patent is to protect the specific idea. It may require numerous trade secrets to make that idea work but these do not need to be given away in the patent.
   - guru - Friday, 05/01/09 22:08:01 EDT

Mr. Turley, Vicopper and Guru, thank you for responding
to my questions above.

   - Mike Thompson - Friday, 05/01/09 22:52:36 EDT

Judson Yaggy,

I don't personally nhave any of the information you require, but I would suggest you contact John Larson of Iron Kiss Powerhammers. I know John built a couple of self-contained hammers before he switched to making only utility air hammers, and he's done a good bit of research on the things. John is generally pretty forthcoming with his insights, so I think you'd find it rewarding to talk with him. Better yet, schedule a trip to his shop in Baltimore and see the self-contained hammers he's built and how he built them.

www.ironkisshammers.com will have all the contact info for John.
   vicopper - Saturday, 05/02/09 01:38:46 EDT

More Air Hammer: Industrial Utility Hammers (Cburgs) have a pressure ratio that starts 15:1 for a 100 pound hammer and then drops to as little as 5:1. The bigger the hammer the slower it is possible to move thus the lower the needed ratio. . . I do not know if this is true in self contained hammers but mayby not as much. When you look at the machines they seem to scale up looking pretty much the same. However, you then have the difference between volume (cubed) and area (squared).
   - guru - Saturday, 05/02/09 08:52:08 EDT

I'd like to know how to harden steel after you have taken soft metal and worked it? I think it is medium carbon steel.
   Verald B. - Saturday, 05/02/09 09:33:01 EDT

Judson, If you are seriously considering building your own self contained you might also want to contact Bob Bergman at Postville Blacksmith Shop and purchase his video on rebuilding a Nazel hammer. With it you will get a copy of the brochure put out by a gentleman (who's name I can't remember at the moment) who built a small self contained hammer. That has an excellent explanation with illustrations of the Nazel air circuit and operation which would be very helpful to you. You might also give Ralph Sproul a call or find him over at forgemagic or farwest. He rebuilt his own Nazel 3B and helped with a 4B recently. I don't think he's too far away from you and would probably be able to help you with the tolerences question. Steve G
   - SGensh - Saturday, 05/02/09 09:42:20 EDT

Verald, LOOK UP!
   - guru - Saturday, 05/02/09 10:43:43 EDT

I have a British Anvil, from what I've found out, could be well over 100 years old. Weighing 242 lbs. The info on the anvil states: Peter Wright Patent, Sound Wrought #2 0 18. If anyone is interested please contact me at the email address above. This is for pick up only. Any help would be appreciated. Thank you.
   - Cat C. - Saturday, 05/02/09 11:58:16 EDT

I have a British Anvil, from what I've found out, could be well over 100 years old. Weighing 242 lbs. The info on the anvil states: Peter Wright Patent, Sound Wrought #2 0 18. If anyone is interested please contact me at the email address above. This is for pick up only.
   Cat C. - Saturday, 05/02/09 12:00:04 EDT

Dear Guru, Did the details on Laffitte plate come through OK?
   - Chris E - Saturday, 05/02/09 17:12:43 EDT

Hard Lead: I know TGN was being facetious with his response about hardening lead; but it did get me to thinking that there are other ways to "harden" metal beyond our familiar "quench and temper" method. Even lead will work harden, a bit, under the hammer (and then the edge starts to crack...). Also, (son of an old hot & cold type printer here) various alloys of lead, especially the addition of antimony, will provide a harder metal, such as you would use for type metal. It would be an interesting experiment (if an impractical project) to see what sort of knife you could make with a higher harness lead alloy and work hardening the edges. I'm sure the bullet casting and reloading guys would already have a leg up on this.

Warm and rainy on the banks of the lower Potomac. I'll be in Denver part of next week, so anybody out that way should give me a shout now. No guarantees, but I will have some wheels and thus some flexibility after working hours (which can really stretch-out when on travel; alas).
   Bruce Blackistone (Atli) - Saturday, 05/02/09 20:07:10 EDT

Thanks for all the input on the air hammer guys! Guru, if I had a week free... well, you know how that goes. And my Machinery's Handbook is currently on top of the stack of books for this project.

Rich- I've been reading archives of all the forums I can find and John L. mentioned so many times that he is now on my list of folks to contact. By the way are you gong to make t to the NEB Fall meet with Steve Parker?

SGensh- I already am acquainted with Ralph and have been occasionally asking him questions about his utility hammer design. Once enough time has passed that I don't feel like I'm pestering him I'll open a line of inquiry on self-contained.

Economically I know that this is going to be a "for fun' project. I have several mechanical hammers that should keep the paying work moving and if I really needed one there is an equipment importer in Montreal that ships in hammers from Europe just 2 hours north of me.
   Judson Yaggy - Saturday, 05/02/09 20:36:17 EDT

Guru - we are still not really talking at the same level on the anvil list. Think of taking a literature final exam. Your position is that you need the whole semesters book set, or at least the Cliff's notes, and I am talking about what I can write on the inside of my watchband to jog my memory. Obviously far from complete but still possibly useful. All your points are very good. I hadn't really given much thought to how vast the subject really is, but I still think that cheat notes can be usful sometimes. Too late anyway. I went to pick up my 25# Little Giant and he had a 1-1-18 Peter Wright than is now sitting next to my forge. The top is relativly flat and has no major dings and only one chip about 1.5" long and maybe 1/8" back into the face. I won't even think of trying to do anything with it since it is centered above the "PETER" and comes down far enough that it might mess it up if I tried to grind it out. Rings like a champ and great bounce. It has the 'solid wrought' in a circle, so it is after 1860, but no 'England' so before 1910 (1890?). Is there any way to narrow this down. My grandmother was born in 1870 so it might be fun to figure out which one came first. The Little Giant is H-8699 and appears to be in better shape 95% of what I have seen on the net. Hope there isn't something hidden.
One very happy blacksmithing student.
   cwsulli - Saturday, 05/02/09 21:51:30 EDT

Who wants to contact me?
   - John L. - Saturday, 05/02/09 22:38:48 EDT


I may make it to the meet at Jim's. I wish it was the weekend just before QuadState, though. That way I could make just one trip North and hit two conferences. Last year I did both Ashokan and QuadState, but it got pretty expensive flying up there twice. I doubt that I'll be able to do that again this year, so I'll probably have to miss the meet at Jim's. We'll see, I'd really like to get up there and see all you guys again.
   vicopper - Saturday, 05/02/09 23:26:25 EDT

I just found the fatal flaw in my logic. The kind of list I want is one that can only be made by the person who wants it. They are the only one who knows what they already know, what they don't care about, and what little memory jogs would be helpful. I can make a crib sheet for me, and you could make one for you, but mine would not help you and yours would not help me. Can't be done by a third party who has no clue as to what can be left out. I guess I did learn from this though, and I am going to start making notes on good tibits I find.
   cwsulli - Sunday, 05/03/09 00:02:47 EDT

Just about any metal can be hardened, even lead. A typical method would be work hardening - it even works with lead but is of short affect for pure lead as it will self-anneal at normal room temperature. To keep any hardness, you'd have to keep it significantly colder than room temperature. At RT, a pure lead wire clamped between 2 points will creep (plastically deform) under it's own weight. We had an example on display in the basement of one of the class room buildings (Doherty Hall, if I remember correctly.) when I was an undergrad at Carnegie-Mellon. Even though it was a basement, it had labs and classrooms in it.

You can also make metals harder by alloying and heat treatment - one example is alumina dispersion strengthened copper used for welding electrodes - a trade name for the product is GlidCop. Steel is rather unique in it's ability to harden through a martensitic phase change on rapid cooling. You can also harden some of the alloys by controlled cooling to transform to bainitic microstructures, some steels harden by precipitation of secondary particles - 15-5 PH stainless would be an example. Some, such as the 300 series stainless or Hadfield's steel (13% Manganese steel) harden from cold work and are not susceptible to hardening from quenching.
   - Gavainh - Sunday, 05/03/09 01:01:23 EDT

Chris, No mail. . . be sure to send it to me at .NET
   - guru - Sunday, 05/03/09 13:25:55 EDT

I am trying to get the belt pulley off the motor for my Little Giant and need some advice from the experts out there. It is a 1 hp A.O. Smith. The pulley is 3 1/4" wide and about 4" in diameter. Looking in from the end, there are 3 bolts, about 3/16", arrayed around the motor shaft about 1 1/2" out from the center and I can see the key way cut into the shaft and pulley. In the pulley body there is what appears to be a narrow slit going out radially from the motor shaft directly opposit the key way and ending at a small lip. The bolts are in the raised area outward from the lip. I can't tell if the pulley is all one part or if it is two pieces, the lip and rim being one and bolted to a central slit core. If it is one piece, then it is not clear to me just what the bolts do. Is this all a press fit, or is there a set screw or pin some place that I have missed? Do I just get it off with a puller and do I pull it with the bolts in place or removed? On the other end of the motor shaft there is a fan casting which is keyed and has a set screw which I have removed. The casting is quite thin and a puller would break it in no time. Any tricks for getting this off? I have soaked both connections with Blaster. Any hints will be very welcome.
   cwsulli - Sunday, 05/03/09 17:13:46 EDT

cwsulli, what you have is a high class industrial pulley with a special hub (Taperlock). Take those three bolts out and then look for a set of threaded holes in the hub that do not go all the way through. Put the bolts into these threaded holes and tighten the evenly. This will act as little jacks and back the tapered hub out of the female tapered pulley, and release the hub from the shaft as well. That hub is slit to allow the tapers to pull the id of the shaft hole to tighten around the shaft. The hub will maybe still be sorta tight and may need a puller, but should come off easy. To reinstall, set the hub where you want it and install the bolts to draw the pulley onto the hub and all goes tight.
   ptree - Sunday, 05/03/09 17:23:56 EDT

Got it. Thanks ptree !!! I suppose you have all heard the story about the engineers fee - $1.00 for turning the screw and $9,999 for knowing which screw to turn.
   cwsulli - Sunday, 05/03/09 18:02:12 EDT

I have a rotary table and would like to find a division chart in degrees and minuets for dividing a circle into any number of parts. I have looked everywhere. Any help from you would be great.
   Kevin - Sunday, 05/03/09 19:22:43 EDT

Rotary Tables and Dividing Heads: Kevin, Many years ago after picking up an old Cincinatti mill dividing head I researched them a little then made a chart of numeric divisions which included almost every integer from 1 to 400 in turns and fractions of a turn. . . Its quite a task. Then I found that my old stand by MACHINERY'S HANDBOOK had the information including change gears for spiral machining with it. . . This is in ALL editions from the 1st to the current edition (28th).

These devices come in several arrangements. The most common is with a 40:1 primary worm gear reducer and a set of disks with numeric divisions and pin holes. At 40:1 a single turn is 9°. One 9th of a turn is 1#&176; an 18th of a turn is 0.5° or 30' a 36th is 15'. . . Both rotary tables and dividing heads come this way. The better ones have a set of "wings" that are set for a certain number of holes in a disk so that you do not have to count them every time.

However, rotary tables also come with reduction rearing for reading fine angles directly. They normally read in minutes directly but SOME read in tenths of a degree. Typical gears in a rotary table are 40:1, 80:1 and 120:1. The last with a wheel divided into 120 minutes (2 degrees).

Mathematically all you need to do is divide 360/X for degrees. If there is a remainder divide 60 by the remainder for minutes and if there is a remainder divide 60 by it for seconds. Note that when you calculate each position you MUST start with the original division, multiply by the location (2,3,4. . .) and then convert to avoid accumulated errors.

However, this is not how accurate divisions of a circle are made. Normally there is a dividing wheel that accurately locates positions without error. If not, the device is setup for simple angle indexing only.

The reason such as chart does not exist is because it would lead to gross accumulated errors. While seconds of a degree are a small part of an angle the fractions of a second add up in a hurry. A chart for equal divisions would have to have a value for each multiple of the division (4 = 0, 90, 180, 270; 6 = 0, 60, 120, 180, 240, 300. . .). A chart with more than a dozen divisions would rapidly become unwieldy.
   - guru - Sunday, 05/03/09 21:22:26 EDT

Kevin: There might be a chart like that in Machinery's Handbook, or You could just do the math.
   - Dave Boyer - Sunday, 05/03/09 21:24:04 EDT

Taperlock Hubs: Note that it is important to evenly tighten the bolts AND not to over tighten. See the manufacturers specs AND use a torque wrench.
   - guru - Sunday, 05/03/09 22:26:07 EDT

hi , i have a largeish table forge (pics on request,), with a small indentation int he center , where the blower and ash pipe go underneath, and a flat bottomed ring of steel around the hole on top, it has 2 grooves in the ash pipe where the clinker breaker should go, but, i cant make one as my forge cant work without it, and i have no access to any other tools,

is there anyone who lives close to calgary that could manufacture one for me? i cant afford to get one from the blacksmith depot, but can pay for shipping and labour

thank you very much
   Cameron - Sunday, 05/03/09 23:25:18 EDT

Cammeron, I'm not sure which part you are looking for. However, many commercial forge parts are handy conveniences but not necessities. Forges can be rigged from almost anything and repairs made the same.

There are many local smiths in Calgary and we've recommended you find them and join their organization several times. They may be inactive but they HAD meetings as the North and South Alberta Blacksmith Guilds. You should be able to contact them through SAIT.

If you are going to be blacksmithing you will either need more tools or more blacksmithing friends. A big part of blacksmithing is make do AND self reliance. That goes farther than just the shop, it includes making phone calls, tracking down people.

On the tools front you can make an amazing variety of parts with modern welding tools. Arc welders and oxy-acetylene equipment each have pros and cons. They complement each other and are best together but each is very useful alone. With either and a hack saw you could probably make the part you need.
   - guru - Monday, 05/04/09 01:44:25 EDT

Dividing Head Math is not very complicated but you definitely need to be up on your algebra and logic. The basic math for a 40:1 dividing head is:

Turns = 40 / Divisions.

IF not equal then the remainder is divided into one of the dividing wheel values that produces an even number and this is added to the turns. When an even number cannot be found then two different values are found that add up to the total. This gets into some pretty tricky math and is where published charts take a lot of pain out of using a dividing head.

IF I was going to do the math again I would write a short BASIC program using integer and modulo math with a little logic and a list of dividing plate divisors. Same could be done for the Degrees/Minutes/Seconds problem.

The American Machinist's Handbook has a brief but very clear chapter on indexing. Machine Tool Practices is not quite as good. MACHINERY'S HANDBOOK has a brief article the common tables and the math.
   - guru - Monday, 05/04/09 02:37:36 EDT

Is is it possible to clay temper a rapier blade without it warping?
   OB - Monday, 05/04/09 05:12:50 EDT

NO. If one edge is hardened it changes in size and will always curve the blade. The narrower the blade the worse the problem.
   - guru - Monday, 05/04/09 07:15:57 EDT

Can you give me any information on the origin of the horse shoe cross LIKE WHO OR WHEN?I am researching for church camp. I to make them some one always ask me this question when I am working in public. Any information would be appreciated
   william schlink - Monday, 05/04/09 08:46:28 EDT

William, I've shod many a horse, but I never heard of a horseshoe cross, so I googled it.

It looks like something recent, probably invented by a Texan with an arc welder the day before yesterday. The hyperbole and facetiousness are intentional.
   Frank Turley - Monday, 05/04/09 10:11:17 EDT

Guru we use a Berrilium bar for chipping out debris in the bottom of a gas main.Have you ever heard of this type of bar being made?- Thanks John
   John DeLuca - Monday, 05/04/09 10:35:02 EDT

Beryllium Bronze AKA Beryllium Copper John, There are quite a number of tools made from beryllium bronze for working in gas and oil service. McMaster Carr sells a full line of these tools including some heavy scrapers.

Beryllium bronze is used to make many tools but must be handled carefully. Beryllium if made into dust is very toxic if inhaled.
   - guru - Monday, 05/04/09 11:28:00 EDT

Guru - I hadn't thought about torque. I have gotten as far a that it a is Martin taper lock and I found their 1000+ page catalog but it is going to take a bit of work to find where they hid the information in there. This raises another question. Isn't the torque going to be affected by the surface condition of the bolt threads etc.?
The parts are not badly corroded, more like the smooth brown on an old rifle barrel. Do the threads and such need to be cleaned and polished? Also, the surface of the pulley is sort of grungy. Should that be cleaned and smoothed or left rough.
Still have not been able to get the fan casting off. I have been "Blasting" and tapping and prying - any ideas?
   cwsulli - Monday, 05/04/09 13:00:54 EDT

Fan casting? Are you trying to rebuild the motor? Newer motors have plastic fans and even they normally end up needing to be replaced after removal attempts. An old one on an old motor may not be replaceable.
   - guru - Monday, 05/04/09 14:38:08 EDT

guru - I am thinking more along the line of preventative maintenance, I scares me to think of what mud daubers nests and other gunk might be lurking inside the housing. I would rather clean it now than fix it later when it grinds to a screeching halt with serious damage to the bearings or rotors. You gave me an interesting thought though, It is an A.O. Smith motor and they still make one thats looks very similar. I will check to see if a replacement is available. I am not a restoration fanatic so a modern plastic one would do just fine.
   cwsulli - Monday, 05/04/09 16:59:49 EDT

cwsulli, I would simply rotate the motor and listen for conflicts on the fan. If the motor is a TEFC, then nothing can get inside the motor proper, only into the cooling fan and housing. Most TEFC (Totally Enclosed Fan Cooled) will say so on the nameplate, but you can also look up the info online from the frame number and so forth.

If the fan rotates well, no noise, etc, than I would leaave it alone, and just use it. If TEFC, and you hear conflicts, pull the housing, but leave the fan alone, since most fit tighly to the motor, and the daubers should be inside the housing. Clean the housing and use WD-40 or similar to wash out between the motor and fan.

I know that per engineering wisdom, "if it ain't broke, fix it anyway" rules, but in this case I would not pull the fan. The housings usually have three or four screws around the end of the housing to secure it to the motor casing.

If the motor is an "Open" type, blow the motor out with compressed air and use a good flashlight to look for garbage in the windings. If no visible, and no noise, and the motor works, drive on. If the motor is an odd size/speed etc, take it to a reputable motor shop and have it cleaned, oiled and checked out for your own sastifaction.
   ptree - Monday, 05/04/09 18:28:24 EDT

Unless the motor has been locked up it is best as ptree noted NOT to take it apart. Hammering on the parts to get it apart is likely to damage the bearings and the act of disassembly can also damage the windings.

These two problems are going to exist or not. Taking it apart is likely to increase it. Motor (ball) bearings are damaged by one of three things besides wear, impact which dents the bearing races, arc burn (from shorts or welding) and rust. If water has gotten into the bearings and merely stained them they will fail shortly and there is nothing you can do about it. The other issues can sometime be detected by spinning the motor by hand and listening for noise or feeling ticking or vibration in the frame.

Clean the exterior rust, put on a light coat of paint and USE it. If it starts making noise, THEN repair it.
   - guru - Monday, 05/04/09 19:08:25 EDT

trying to find the flat layout for a mitered 90deg elbow, basicaly building a large stove pipe elbow
   george - Tuesday, 05/05/09 11:51:35 EDT

Hardening a medium carbon steel: For what is the first question, is this to be a knife or a spring? A bearing or a chisel? A prybar or a die for a powerhammer?

I'm going to assume a knife because that's what we usually get when someone has spent a lot of time and effort working on something only to find that what they used will not work for what they made *after* they have put in the work.

Medium carbon steels are at the low end of usability for knives many of us liking High Carbon Steel for knives; but it can be used 5160 is a common steel used for handforged knives.

So using junkyard (unknown alloy) steels the first thing you need to do is to make a test piece about the same size and shape as your piece out of the same material so you can figure out heat treat for it without destroying your good piece.

So first Normalize: heat to above where a magnet will stop being attracted to the piece and let cool in still air. Repeat twice more

Second: Harden: heat to above where a magnet will stop being attracted to the piece and quench. If you don't know the alloy try warm---say 140 degF vegetable oil first and check the hardness with a good file (and be aware that there may be a decarb layer on top that will seem soft but the core will skate the file!) Be prepared for the oil to flare up and make sure it's in a metal container---I know a smith who burned down his shop quenching in a plastic bucket...

If the file doesn't skate: reheat and try over with brine or water: If it doesn't skate then your alloy cannot be effectively hardened for a knife.

Remember to leave the edge at least as thick as a dime to a nickle to help avoid warping and all scratches should be removed first to help avoid cracking.

After Hardening you need to temper: reheat in something like a cook stove to a much lower temp 375 degF - 600 degF depending on the alloy, quench and what you want from the blade.

Tempering should be done IMMEDIATELY after hardening---have the oven preheating when you go out to harden.

Easy no?

   Thomas P - Tuesday, 05/05/09 12:52:30 EDT

Clay hardening a rapier; yes it can be done with the right alloy and the right rapier design---the earlier ones would work better than the late ones. You would need to clay the center and allow both edges to harden.

You would then end up with a rapier that will be a far inferior blade to one that was hardened and tempered in the way they were in Europe. A rapier greatly benefits from a spring tempered core rather than a soft easily bent core.

   Thomas P - Tuesday, 05/05/09 12:55:20 EDT

George, Elbows and T's are theoretically sine curves when laid out flat. Most are laid out by simple projection (dividing the flat by equal parts and transferring dimensions from a circle also divided equally. How to do this can be found in drafting (engineering drawing) books and sheet metal working books. Once you understand projection its pretty simple. All that you need is a compass or dividers and a straight edge.
   - guru - Tuesday, 05/05/09 13:11:21 EDT

A quick mostly unrelated question about bow making(archery).

How do bowmakers(?) get the wood to be springy instead of cracking when the bow is drawn?
   Nabiul Haque - Tuesday, 05/05/09 15:50:45 EDT

I'm doing a restoration on a fence that has posts set with lead, anyone have tips on removal?
   andy - Tuesday, 05/05/09 17:51:49 EDT

Nabiul, Its all in the type of wood. But for powerful bows other materials have been in use for thousands of years. Horn and other materials were used in laminations and then metals and finally fiberglass and technical fibers in plastics. Wooden springs were used for many other things and woodworkers knew which woods and how to select them.

To make powerful all-wood sprung bows the length had to be increased (as in "long-bow") to reduce the stress on the wood.

Making an all wood bow is also an art. Grain is always absolutely parallel to the front (all taper is cut on the back), and layers perpendicular to the flex. It must be absolutely knot or imperfection free. And as I started with, the type is important.

I've made wood, wood and fiberglass and metal bows but never really studied ancient bowmaking. The all-wood bows were made of clear maple laminated much like the cores of modern fiberglass bows. The major difference was power.
   - guru - Tuesday, 05/05/09 17:58:05 EDT

Removing Leaded Anchoring: Andy, I contacted a friend of mine who has done a lot of repair work as well as installing rails by leading. He says there is no good way. These are designed to be a permanent installation. Your best bet is to rig up a clamping device and use two hydraulic jacks to pull the post out. Depending on the rail design you may have to work one post then another a little at a time. IF you are lucky and the posts are straight (not upset or toothed) they will pull out. This also assumes there is room for two jacks.

Good leaded jobs have snug fits. But if there is enough room you may be able to drill out much of the lead. Note that some leaded jobs have iron or steel wedges locking the post in place and the lead is there to seal and water proof.

One way to grab a post is an L over D (L/D Length over Distance) locking device. Ideally these have a hole that the bar passes through but they can be slotted to fit from the side.

In the restoration of a leaded rail there are many considerations. As a permanent installation the stone work may be damaged and need to be replaced. A repair rail may want to be fitted over the stubs of the old rail. Repairs may want to be made in place OR the rail disassembled in place and the posts extracted individually.

Good Luck!
   - guru - Tuesday, 05/05/09 19:30:42 EDT

Judson: A fella by the name of Mark Krause wrote a small book called "The self Contained Air Hammer" explaining much of the workings and showing a hammer he built.
   - grant - Tuesday, 05/05/09 22:35:34 EDT


What's wrong with melting the lead? Worked for me just fine, even working close to edge of granite.
   Peter Hirst - Tuesday, 05/05/09 23:05:03 EDT

Rust Patina - I've been commissioned to build four steel signs for a new subdivision here in Idaho. Much of the 4'x4' areas call for a rust patina. What do you recommend for these areas for treatment to get a rust patina?
   arlo - Wednesday, 05/06/09 00:13:36 EDT

(sorry, I couldn't let that opportunity pass...)
   - Charlie Spademan - Wednesday, 05/06/09 07:34:04 EDT

I have a homemade forge with a little buffalo blower I put on it. Theres about 20 inches of 2 inch aluminum flex hose that goes from the blower to the fire pot. sometimes I add water to the coal surrounding the fire while Im working to keep the fire down, and occasionally I get a pretty good (boom) when I do this. Usually I keep the blower going while I add water and this doesnt happen but the other day I got one that actually scared me a little. please tell me if this is something I can fix or is there something Im doing wrong. Thank you
   zack - Wednesday, 05/06/09 10:44:57 EDT

Zack, I used to have that problem running a little rivet forge blown with a hand-crank blower through a 3" flexible duct. When it went off in a big way, it blew 10 inches of duct completely apart, temporarily deafened me, and made my wife come running to see how many pieces of me she could find to try to stitch back together.

The only real solution is to always be sure you've got some air going when you water your fire. Or, don't water the fire to begin with.

One thing I did that seems to help is to make sure that no part of the flex duct is lower than the place it connects to the firepot. This prevents heavier-than-air explosive gasses from pooling in the duct.

For some reason, my old rivet forge did that fairly often, but my Centaur firepot doesn't do it at all. Or maybe I've just conditioned myself to be certain I'm always turning the crank when adding water to the coal. That one explosion was enough for me.
   Alan-L - Wednesday, 05/06/09 11:02:40 EDT

I forgot to mention the time they releathered the ceiling-mounted great bellows at the Tully Smith house (part of the Georgia History Center in Atlanta where my wife used to work long ago) and they put one of the check valves in backwards, allowing some reverse aspiration into the system. The resulting coal gas explosion not only destroyed the bellows, but blew a large hole through the shop roof. They found the top board of the bellows out in the yard about 50 feet away, with a trail of wooden shakes (handsplit shingles) leading back to the shop.

The moral of this story, and the one earlier, is to always be sure your air blast is doing what it's supposed to if you intend to water your fire at all.
   Alan-L - Wednesday, 05/06/09 11:10:49 EDT

Thanks for getting back to me so soon. Ill give these Ideas a thinking and get back to It. I really appreciate it.
   zack - Wednesday, 05/06/09 11:15:29 EDT

I just got your second post, before I sent my thanks. do you think its a good Idea to maybe not use so much water or maybe add just a little bit, more frequently.
   zack - Wednesday, 05/06/09 11:24:47 EDT

Bow making: using air dried wood instead of kiln dried helps too!

   Thomas P - Wednesday, 05/06/09 12:28:36 EDT

Hello Guru(s),

My question is about camp fire grills and warping. I fabricated a large steel grill for campfire cooking, with square tubing and expanded steel mesh. The mesh has warped severly after use. I tried freeing the mesh so that it could slide when it expands, this made the problem worse. My second approach was to weld it down in as many places as possible, this helped a bit, but it is still pretty much unusable.

Do you have any tips/advice? Would it help to go to a thicker mesh or to use a wire weave grid instead? I would also prefer to keep the weight down.

Thanks a lot,
   Hayes - Wednesday, 05/06/09 13:03:39 EDT

Zack, what I do now is just add water when I think it needs it, which varies quite a bit depending on what I'm doing. I use an old soup can on a stick (well, a forged steel swiveling rod) as my watering can. To keep the mess down, punch the holes high on one side of the can instead of on the bottom. That way you can sprinkle just where you want it by tipping the can towards the row of holes, instead of leaving a swath of water all over the place.

You're using too much water if it stays pooled atop the forge or runs out the bottom. A lot of people don't use water at all, but I'm a cheapskate and like my coal supply to last as long as possible.

If you were using charcoal you'd just about be forced to water it down to keep the fire from spreading.
   Alan-L - Wednesday, 05/06/09 13:20:08 EDT

Rust Finishes: These can be accelerated using many substances. Chlorox liquid bleach is the simplest and most common.

However, stopping rust is the problem. If the spec is a rust finish then point out that rust does not stop and eventually the work will be dust. Clear sealers applied over the the rust will slow it but not stop it and will fail.

If you want rust color and texture, then learn to paint. Texture the surface OR the paint and use red and yellow oxides along with brown.
   - guru - Wednesday, 05/06/09 14:30:24 EDT

Pops and explosions in forges: This is gases from the raw coal collecting in the tuyere and igniting when it either builds up to an explosive mix with air OR when it is pushed back into the fire. It has nothing to do with adding water other than the steam blowing the gasses back down the tuyere. The problem is most common where there are long pipes or bellows to fill with gases. Bellows have been known to be blown to bits by coal gas explosions.

A problem that occurs occasionally is the gases are blown back into the tuyere by the wind or air movements. This is most common outdoors but the same can happen indoors. Once in a while simply opening the wrong combination of doors and windows can create or cure the problem.
   - guru - Wednesday, 05/06/09 14:52:22 EDT

Warping Steel Mesh: The problem is the size and shape of the expanded metal. When it is heated it buckles much like the sheet is made from then takes a bend which does not change when cooled. The best replacement would be a bar grate.
   - guru - Wednesday, 05/06/09 15:06:27 EDT

Well, we can't always agree can we? Before natural gas many cities ran their street lamps from "gas plants" that made a flammable gas (producer gas) by blowing steam into heated coal in retorts.

From Wikipiedia: Originally a by-product of the coking process, coal gas was extensively exploited in the 19th and early 20th centuries for lighting, cooking and heating.

I would think that is also being produced in the forge when we add water.
   - grant - Wednesday, 05/06/09 16:05:24 EDT

I am guessing here but some of the booms in the little forges could be due to the formation of hydrogen. Water will dissociate into H2 and O2 at sufficient temperatures and then violently re-combine if a source of ignition is present.
   quenchcrack - Wednesday, 05/06/09 16:07:58 EDT

Thanks Grant. I'll look into it.
   Judson Yaggy - Wednesday, 05/06/09 16:51:00 EDT

Grant, You are probably right. But I've had plenty of explosions from the yellow smoke that comes off a green coal fire and without any water added. I suspect both happens.
   - guru - Wednesday, 05/06/09 16:51:14 EDT

Coal gas. Louisville KY had 13 caol gasification plants around the city to produce gas for lighting and cooking and so forth. In fact one had been located on property next to the valve plant that we bought. The prperty we bought had about 20+' of fill, all refractory, furnace bottoms and ash. We bought another property on the next side around from that and I was given the project to build a paved parking lot for 250 cars. In the leveling of the lot we found perhaps 10' of fine grainy black ash. I suspect that was from the same caol gas plant.
Found out later the first property was severly tainted with benzine. Seems it was used for something in the process, and all 13 former sites were laden with benzine.

Producer gas was used at one time to run huge low speed combustion engines for blowing the furnaces at many steel mills. Producer gas is usually mostly carbon Monoxide. Add some more oxygen and it will combust.
   ptree - Wednesday, 05/06/09 17:40:34 EDT

Have we all had compactions? I think my forges get them at times because of the bottom blast. It seems that with continued use, the fire gets "heavy" and settles over the tuyere. That's when the smoke has little upward outlet and goes instead into the blast pipe where it collects. Starting the blower can create just the spark needed to cause an explosion.

Occasionally, I use a straight poker to lift the fire from the tuyere, and I shake and disturb the coals a bit. I also give a couple of shakes to the clinker breaker. This not only gets rid of the compaction, but your fire will come to life again.
   Frank Turley - Wednesday, 05/06/09 18:23:26 EDT

I get compactions sometimes, but then a little Senokot or Dulcolax takes care of it. Never used a coal forge, so I have no idea what you guys are talking about.
   - Nippulini - Thursday, 05/07/09 08:19:02 EDT

explosions in the bellows:
I thought it was common practice for safety, to construct the nozzel of the bellows so that it only blows into the tuyere but is not conected to it like on an edjuctor nozzel(not sure of the spelling) just for the purpose of avoiding a back blast such as this?
   - merl - Thursday, 05/07/09 09:05:41 EDT

Merl, that's how the thinking folks do it. ;-)

When I blew my blast pipe to shreds, the explosion seemed to be centered at the lowest point in the duct. And I think it was just that bit of extra oxygen when I started cranking again that set it off. Darned near filled my pants when it happened, too, which would've helped if I had Nip's compaction issues...

Frank, I do that too. Seems like after about two or three hours of heavy forging the fire needs to be taken apart and put back together, and not just to get the clinkers out.

   Alan-L - Thursday, 05/07/09 09:50:55 EDT

For those who may need help with dividing heads and other little shop problems, mostly machine tool related. Here are some great little computer programs, some I have used, that work well and are supplied Totally free by their respective authors. I thank them many times over for their generosity!
You to may find something useful here.

   - tmac - Thursday, 05/07/09 09:59:43 EDT

Some coal seems to tend to compact around the fire like Frank mentions; other coal never had a problem with it. Some coal tends to produce a lot of "ash" that looks sort of like coke but won't burn. The clinker breaker/sifting it into the ashdump is your friend. Other coal cokes into large chunks and leaves little clinker or fly ash.

Boy I miss the good stuff!


   Thomas P - Thursday, 05/07/09 10:11:27 EDT

Dividing Heads: I should have known there were some handy dandy dividing head programs out there.

On the other hand the math is not that complicated and anyone using one should at least do it the hard way a few times for practice. You don't always have a PC or Internet connection handy but you almost always have a pocket calculator. Shop math is part of the job. For the parts you cannot remember MACHINERY'S HANDBOOK has the answers.
   - guru - Thursday, 05/07/09 12:43:43 EDT

Forge Explosions: These occurred fairly often in my portable shop. I learned to always give the bellows a very gentle short pull that did not lift the top of the bellows. When the gas ignited with a "whomp!" it would lift the top of the bellows to its full extension. I had learned when the bellows was new and very strong that you did not want to pull hard on that first stroke. Otherwise with the bellows fully extended the explosion would have nowhere to go. It is sort of like double clutching. Once you get used to it you do it by habit without thinking about it.

On hand crank blowers with good piping the blast should just go out the intake. I've seen fire pop out of blowers about a foot. It shouldn't hurt. However, lots of folks use flexible tubing. I did enough automotive work fixing and repairing flexible pipe that I have no use for it.
   - guru - Thursday, 05/07/09 13:03:11 EDT

Howday, Folks:
I just finished relining my three year old Ebay purchase propane forge using the excellent Anvilfire demos from the Guru and from Quenchcrack. I have one unanswered question. I want to use some Kaowool (or whatever type of soft refractory blanket it is) as a gasket for the front and rear doors, but I don't know what to use to affix the kaowool to the sheer metal face of the door or the area surrounding the door. Would you suggest using more of the ITC-100 that I used for the interior refractory? I'm assuming that wood glue won't do the trick! :>

All my best,
   Arik Greenberg - Thursday, 05/07/09 13:13:53 EDT

Door Gaskets: ITC-100 works but the blanket tends to shear in layers. The way NC does it is to box the blanket and use screws from the sides like nails or fingers to hold the blanket. The problem is that they use 2" blanket which is hard to get. When you need thick blanket it is common to make it into an accordion fold using a fixture to support it and sweing it together with stainless or inconell wire (recommended for forges).
   - guru - Thursday, 05/07/09 13:28:43 EDT

Where can I find about the dangers in dealing with galvanized fumes from welding or burning off galvanized coating. I know I've seen it before, but can't find it now.
   David - Thursday, 05/07/09 13:46:55 EDT

Rust finishes--- Angiers book, Blueing and Browning of Firearms has several 'rust killing' formulas in it. Without them we would have no old 'browned' guns to examine.

Steaming or boiling in plain water kills rust dead and forever, but it darkens the metal. Repeated rustings, boiling and carding of the dust that remains creates 'rust blued' finishes. In my opinion the very finest metal finish mild steel can have.
Protect it with a 3:1 mixture of turpentine and spar varnish (or linseed oil, if you are a purist). Fine firearms are protected by hardening oils marketed in England.....mainly for their aroma.
   - JBelk - Thursday, 05/07/09 13:56:12 EDT

Re: door gaskets- Thanks for the advice, Guru. I actually made the doors and hinges myself out of .100" thick steel plate, since the original forge came open ended at both sides. They are flat, so I won't be able to box the blanket in like NC does. I had considered that, though, but it appeared to be too much work to make two doors that way at this point. I'll probably just try some ITC-100 to hold it in place and cover the entire 3x5 inch surface area of the door and see what happens. Thanks again.
- Arik
   Arik Greenberg - Thursday, 05/07/09 14:57:11 EDT

Galvanized Hazards: David see our iForge page (top).

Note that common galvanizing is zinc and is a marginal hazard that you should avoid welding over or burning off. But other coatings including some old mixed galvanizing may contain lead and cadmium. Cadmium fumes are just plain lethal. Cad coatings are often found on hardware and particularly military stuff. Microscopic amounts over years of exposure will cause all types of internal organ failure. Larger amounts can kill.

In short, don't weld on galvanized parts without grinding off all the coating in the weld and HAZ. Don't burn off galvanizing. Avoid all fumes from coated metals of any kind (including paints).
   - guru - Thursday, 05/07/09 15:58:59 EDT

Ptree: I thought that benzine was a common component of coal tar and so would be all over the place around anything that coked coal.

   Thomas P - Thursday, 05/07/09 16:04:04 EDT

Hello everyone, I've been blacksmithing now for about six years and I think my work is now to a standard that I would like to get my own touch mark to sign my work. It is very exiting for me to get my own touch mark. I want the stamp to be of the best quality and last for a very long time(you understand what I mean) So, which of these two companies do you guys would be the best for the job?

Both seem well qualified, but I have had no experience in designing and purchasing a custom steel stamp.
Also, what are some of the common mistakes in designing one of these stamps, any suggestions from your quys experience in touch marks. Thanks a bunch
   - John L. - Thursday, 05/07/09 17:36:56 EDT

John, just keep it simple. A touchmark should not be too big or you cannot put it on smaller sections. A complex design is not easily recognized when it is small.
   quenchcrack - Thursday, 05/07/09 18:35:58 EDT

ThomasP, I think benzine is indeed a coal tar deritive, but the levels forund were reported to be far in excess of what was expected from the waste dumped. May have been used as a solvent in the process as well.
We ended up building our then new powerhouse on a different plot since the levels were so high. I got to run that powerhouse about a year after it was finished and it only ran for 4 years total before it was mothballed, and then sold and removed. 4 million for the powerhouse with 2 each 850 Hp (82500 #/hour) steam generators. :(
   ptree - Thursday, 05/07/09 18:43:25 EDT

Sam Yellin's touchmark. When I was at the National Cathedral in Washington DC, I lifted up one of the large drop/ring handles on one on his gates. I turned it upside down and stamped on the back was his mark: YELLIN.
   Frank Turley - Thursday, 05/07/09 20:34:28 EDT

I do quite a lot of Hebrew based sculpture work. So my touchmark is a Star of David inside an outline double bick anvil. I didn't want letters because I wanted something that a non English speaker would recognise. I got mine made in China and it works well. The mark is about 17mm wide by 6mm high (3/4" x 1/4")
   philip in china - Thursday, 05/07/09 22:15:31 EDT

Thanks for the suggestions, does anyone know anything about the two companies above - as far as which one might be the best one to go with.
   - John L. - Thursday, 05/07/09 22:57:37 EDT

If it's letters though you can easily google for it on the net. A "picture" is much harder to trace.

We sometimes get this in the SCA when we see modern armour reproductions being sold as antiques. We know that maker's trademark is recent but the sellers/buyers perhaps were not able to research it properly.

   Thomas P - Friday, 05/08/09 11:48:19 EDT

If I were looking for a touchmark, I would purchase a Blade magazine and see which companies the knifemakers are getting their stamps from as knifemakers are Very picky on quality. I purchased one from one of the advertisers years ago and it works great.Never heard of the 2 you mention.
   - ptpiddler - Friday, 05/08/09 12:00:37 EDT

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