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

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

This is an archive of posts from July 24 - 31, 2007 on the Guru's Den
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Ah. . Arron, . .. On most trucks when it says 1,000 pounds that means BEFORE you fill it with fuel (about 150 pounds), add driver and passenger (another 300 to 500 pounds). So subtract 450 to 650 from that 1,000 at the get-go. Then you subtract the tools, chains and other rigging you tossed in.

They may have gotten better about this, but that was the way they used to do it. Then there are 4WD trucks that are all rated at 3/4 ton but have 1/2 ton springs. . . Real 3/4 ton trucks are rated at a ton or more so that when you subtract the fuel and passengers you still have 3/4 ton. A least my old Dodge was. My F600 "ton" truck is actually good for five or more strictly depending on the way you license it. I don't think fuel and passengers make an actual difference on this truck except when you cross the scales.

Drill Press: You have a real find there, especially if you have a use for it. Mine was OEM motorized. Not sure of the HP because the motor is kind of funky. It also had a foot switch and a by-pass all of which is also very funky and needs to be replaced.
   - guru - Tuesday, 07/24/07 08:28:31 EDT

Hi wish you well --I need to know more about the Temperature to Temper steel at and what the hardness will be it a given tempering Temperature is there a chart on the one in common use like car spring and files
   tecnovist - Wednesday, 07/25/07 12:00:18 EDT

Temper vs. Hardness: Tecnovist,

See of FAQ's page, Temper Color Chart

Also see our FAQ, Junkyard Steels

AND our FAQ, Heat Treating
   - guru - Wednesday, 07/25/07 13:15:52 EDT

RR Steels:

I know there are standards governing railroad steels, and I know that rail itself has approximately 70 points of carbon. But can any of you good folks tell me anything about rail anchors? (Photos to clarify what I'm talking about: http://www.unitrail.com/) I'm pretty confident that there must be some sort of standard that governs what steel can be used in them, but I haven't been able to find it. The one maker's site I referenced above says that their spring anchors are made of "high-carbon, high-manganese, heat-treated steel." If one maker's making them that way, I assume that's what the market demands. So I'm guessing other makers' products are similar. But can anyone here tell me more than that?
   Matt B - Wednesday, 07/25/07 14:12:24 EDT

What did they say when you sent them e-mail on their contact site?

   Thomas P - Wednesday, 07/25/07 15:36:43 EDT

I would like to make charcoal, in a suburban area. I have been reading through the FAQ page, and I am a bit confused about the barrel method. I want to use a burn barrel, and pipe the off-gases back into the fire to reduce smoke.

Is the fire supposed to be in the barrel or below the barrel or are these two different methods?
   Hayes - Wednesday, 07/25/07 15:53:22 EDT

Hayes, Those are two different methods.

When you burn IN the barrel you start with a big blaze, toss in more wood and throttle back, then close to put out the fire and let the heat finish the job. You get a mix of finished charcoal and some semi-finished.

When you burn outside the barrel a lot of gases are given off. At first it is steam. That goes on until the wood is dry. Then it is various volatiles which depend on the wood type. You get a lot of turpentine and tars from coniferous tree wood. This will burn if you direct it into the fire box and increase your efficiency. At the end you get "wood gas" which is the lighter volatiles and gases produced by the hot carbon and hydrogen (similar to natural gas). This also burns. When the gassing off stops completely then you have charcoal.

In both cases you need to be sure that the charcoal cools before opening the container. Hot charcoal will burst into flame on its own with a little air and any hot dust may make a small dust explosion or flare up.

Most methods of making charcoal require practice and attentiveness. The old pit method requires careful stoking and tending the vents for 12 to 24 hours. Fall asleep and let the fire get out of hand and a complete firing can go up in flames in minutes.
   - guru - Wednesday, 07/25/07 16:31:59 EDT

I'd like some info that goes right along with Hayes' question. How big of a piece should I be cutting the wood into? I am driving a Boom truck for a waste disposal company so I know where to get lots of large chunks of wood. XD
   Daarian - Wednesday, 07/25/07 16:41:45 EDT


Thomas, good question.
   Matt B - Wednesday, 07/25/07 16:52:41 EDT

I'm not a guru, but I do live in the 'burbs and I started smithing using homemade charcoal as my fuel. Making it without ticking off the neighbors is tricky. (The first rule of suburban smithing is to maintain good relations with the neighbors.) I usually did my burns very late at night. Be careful not to violate any local burn ordinances or the like. In some places it may not be legal to make your own charcoal at all.

Big chunks of wood take a lot longer to char all the way through, because it takes a long time for their centers to get hot enough to boil off the volatiles. And if your wood isn't all of a fairly uniform size you'll either: (1) burn up a lot of the smaller pieces waiting for the big ones to char all the way through, or (2) end up with a lot of uncharred wood in the centers of the big chunks.

I had the best success (least waste, fewest incompletely converted pieces of wood) starting with relatively small, uniformly sized pieces of wood. By "relatively small" I mean perhaps 2"-3" thick in the smallest dimension. I used a lot of raw lumber scraps, which worked great. They're pretty readily available in the 'burbs, at least around here, they've already been kiln dried so they normally burn very well, and they come in uniform sizes. Don't use treated lumber; the stuff it's treated with is nasty, and you don't want to breathe it. It's probably wise to avoid finished woods for the same reason.

The hassle of charcoal making in the 'burbs is what ultimately prompted me to switch to waste fryer oil (and sometimes diesel, when I run out of waste oil) for fuel. That's not entirely hassle-free, either, but the stuff's easy to get and requires very little processing.
   Matt B - Wednesday, 07/25/07 17:26:37 EDT

Thanks for the info.. I can always cut the stuff down smaller, its just easy to access free wood :D
   Daarian - Wednesday, 07/25/07 17:33:15 EDT

Split up short pieces are best as Matt noted. In the forge you will want to break them down to about 1" to 1.5" (25 to 40mm) lumps. Bark free coals best as bark tends to be full of minerals and also dirt from handling the logs. Recycling scrap lumber is excellent for charcoal.
   - guru - Wednesday, 07/25/07 18:16:22 EDT

I am gonna be recycling the logs people cut off of their trees since I spend all day picking it up anyway. Thanks for all of the information. Now I just need to find time to build my setup.
   Daarian - Wednesday, 07/25/07 18:31:36 EDT

can you please give me some ideas on how to forge bevels on a double egded blade. I've tried several ways ,but nothing seems to work very good.
   troy - Wednesday, 07/25/07 19:14:59 EDT

Troy, Double edge is easier than single as the result is self straightening.

You work on the edge of the anvil with the blade parallel to the edge. Work in short sections flipping the work over to work the opposite side regularly. Using a square rocker faced hammer works better for this type work than a round faced hammer. The rocker face moves the steel predominantly in one direction which is better for making a wedge shape.

Doing smooth clean work of this type takes many low red heats and takes a lot of time. Working small sections at a time can result in work that needs little grinding and clean up.

And as in everything else, practice, practice, practice. All precise forge work is difficult until you have considerable experience.
   - guru - Wednesday, 07/25/07 19:39:48 EDT

Does anybody have plans for a stand to hold a leg vice please? I want something I can move around.
   - philip in china - Thursday, 07/26/07 05:45:02 EDT

Philip, See our Vice FAQ.

This stand works fairly well but needs to be on a stiffer plate, 3/8" is too thin, OR it needs to have some ribs extending out into the plate.

The advantage to this stand is that you STAND on it. Since you are on the vice it cannot be moved by any force you put on it. To move it you just tip and roll. The plate could be quite heavy and still be portable. I like the thin plate because it is not a trip hazard.

Another heavy but portable stand is a 55 gallon drum that will be filled with water. It is both vice anchor and quench tank. The disadvantage is you must drain the water to move it.

To build you need an open end 55 gallon drum, preferably the heavier steel type. A wood bracket/shelf it made that attaches near the top or at the correct height on the drum. It will need to be cut curved to fit and should extend as far as conveniently possible to stiffen the drum. Otherwise a wide bar of steel will need to be fit to the curve of the drum and bolted to the inside along with the bracket from the outside.

At the foot of the vice a plate should be welded to the corner of the drum with a hole for the foot. You will also want to make a screen to fit about 1/3 the depth of the drum. Otherwise parts tossed in to quench will be in 3 feet of water and you will not be able to reach to get them out except with tongs. . . Old deep fat fryer screen (SS) work well. It is also helpful to install a hose bib (valve) to the lower side of the drum to make it easier to drain.
   - guru - Thursday, 07/26/07 09:17:47 EDT

Daarian's Charcoal -- It's hard to make charcoal without producing smoke. A couple things that may help cut down the smoke are, split the wood small, like everybody says, allow green wood to season a week or two after splitting. And a method of burning that may help, is to burn it in a trench and quickly smother it out when done. Split a steel barrel in two lengthwise and dig a trench so that the pieces can lie end to end (making a long trench) flush with the ground. Build your fire in the trench, get in hotter and hotter, so that it can handle more and more wood with little smoke. Burn until it's all charcoal, put a piece of tin roof over the trench and shovel dirt on the edges and any holes. This will extinguish the fire pretty quick, but it will continue to smolder at least in a small area if you have any little crack. So put more dirt on any place that you see smoke rising. It ought to be cooled down in 12 or 18 hours. I suppose you could put the fire out with water. A lot of people say to wash charcoal. I say sift it through wire mesh. You'll have what looks like a worthless pile of ashes when you get done burning, but you'll find lots of charcoal when sifting.
   JohnW - Thursday, 07/26/07 09:39:40 EDT

Thanks for the info on charcoal, time to get started!

Matt, how does your waste oil forge work? How hot does it get? I am interested in cheaper, more sustainable metal heating methods.

   Hayes - Thursday, 07/26/07 11:22:55 EDT


I too, would like to hear more about your oil-fired forge. Propane is so expensive down here, and theeres no coal, so oil would be a good fuel. I know that industrial oil-fired forges get hotter than propane, and run much cheaper, so I'd like to hear more about yours.

Send pictures if you have them, too. I'd really appreciate it. richATcaribbeanblacksmithDOTcom is my preferred email address.


Rich Waugh
   vicopper - Thursday, 07/26/07 11:46:19 EDT

Does your work come out smelling like fries?

   - Nippulini - Thursday, 07/26/07 12:39:14 EDT

What is that tool used by Japan swordsmiths I thinks its called a sin or sen. I think it is used for planing the blade and removing forging inprofections. Can you tell me a little more about it. I would like to use one in my blade smithing if there is a way to fin or make one.

   troy - Thursday, 07/26/07 13:10:14 EDT

Troy, a sen is a draw knife for metal. I have a photo of a Chinese version that I will post in a few minutes.

They are made in various shapes. Flat for smoothing, replacing a file. Curved for cutting fuller grooves. The cutting steel can be hand forged, hardened and tempered or a piece of good factory hardened steel like a lathe cutter bit. Photo in a few moments.
   - guru - Thursday, 07/26/07 13:35:28 EDT

Chinese Blacksmith using Sen on clamp bench

Sen and wedge operated clamp bench

Chinese Sen detail from above.

Photos by Sean Walker, Dujiangyan, Sichuan, China.

He says living in China is like going back 500 years in time. The smith's shop is very small and he has to pull this bench out in the street to use it.

The bench (shown above on 7/17) is a type of wedged clamping bench or "vice". The end of the board has a V shaped cut out that is well worn. I suspect it is also used to support work for scraping or filing.

The Japanese type clamp is a board that sets on the floor and has a U shaped staple similar to the above except that the work is clamped directly down on the board with wedges under the clamp.
   - guru - Thursday, 07/26/07 14:32:13 EDT

Joy.. this has nothing to do with blacksmithing, but I thought I would share.
I operate a boom truck that picks up debris and typically I don't bother wearing my Safety Glasses, but today the wind was blowing and I didn't want all that crap in my eyes so I put them on. Now I am thankful that I did, because as soon as I lifted the boom up a hydraulic line busted spraying me in the face with nice warm hydraulic fluid. What a day.
   Daarian - Thursday, 07/26/07 16:56:29 EDT

Daarian, You are lucky. At full pressure a pin hole leak in a hydraulic system can pierce the skin, inject oil into the blood stream, and even act like a hydrojet knife and cut parts off. . .
   - guru - Thursday, 07/26/07 18:05:53 EDT

I second the GURU, and add that from my experience around a lot of high pressure hydraulics that when hydraulic fluid is injected, it is a automatic infection.

Second thing, if the fluid hit you with much force, be sure to report to your company, as you may end up with a workers Comp claim. Hydraulic fluid will sometimes cause a pretty heavy rash, or what appears to be the worst case of acne ever seen in some cases like this.

For all, hydraulic oils have additives that tend to defat the skin when in extended contact, like wearing a soaked garment all day. Same issue, oil dermatitis.

And last but not least for all those out there who only sometimes wear safety glasses, lets take the "Safety Nazi's" online safety glasses test.
Close both eyes tight and decide what you can see.

Any questions?
   Ptree - Thursday, 07/26/07 18:19:28 EDT

Ptree: I see my wonderfull wife telling me she has just bought 3 large triphammers for me and wanting to know if a 100'x100' shop extension would be an appropriate wedding anniversary gift for me....always had a good imagination...

   Thomas P - Thursday, 07/26/07 19:18:33 EDT

We're getting ready to leave for vacation, and I don't really have time to answer questions about the oil burning forge in the depth I'd like to. But here's a drawing I did for someone else who asked about it, which explains most of what you need to know, plus a couple of photos of the forge.




How hot does it get? Hot enough to destroy itself. It's closely based on a backyard foundry that the designer uses for casting iron: http://www.artfulbodgermetalcasting.com/. He's inadvertently melted steel in it. I have not forge welded in this one, but in a moment of inattention I half-melted/burnt a stainless steel work support that I had installed in the forge. (It was a bad idea anyway.)

How much oil does it use? I'd guesstimate about 0.75 gph of waste fryer oil at a forging temperature. Less with diesel. (Offroad is cheaper!) Inside dimensions are roughly 10" diameter by 20" tall.

I've switched to a simpler, more robust tuyere design since I did this drawing. It's basically a 2" black iron pipe tee with a nipple in one end and a nipple coming in the side. The other end of the tee is closed with a plug. Fuel line (0.25" ID copper tubing) runs through the plug (it's soldered in), straight down the long axis of the tee, to the end of one of the nipples. That nipple is necked down like the original tuyere shown in the drawing. The other nipple attaches to my blower. It has a few small slots cut in the side to allow air from the preheater tube to enter and mix with the fresh air heading into the forge. I've eliminated the heat shield and the pass-through heat exchanger, but that was just so I could fabricate the new tuyere quickly. I may add them back in at some later date.

The fuel line outside the plug is attached to a compression fitting with a hose barb, which attaches to a vinyl fuel line that runes to the fuel tank. Fuel flow is metered by a poor man's needle valve, a.k.a. a multi-turn plumbing valve (the kind that feeds your toilet) -- $6 from Home Depot. My blower can put out 200 CFM; I control air flow with a router speed control from Harbor Freight. For a forging temperature I have the speed control set at about 1/3 maximum or a little more, probably around 60 CFM.
   Matt B - Thursday, 07/26/07 22:10:13 EDT

Forgot to add: fuel is gravity fed.

Also forgot to add that this design requires me to preheat the forge before I turn on the oil. A good sized oil soaked rag with a gentle air blast is usually enough preheat. When the forge gets reasonably hot I can gently crack the fuel valve. Reducing flame at first. Then just add a little oil and a little air at a time. I can get it to a forging heat in less than ten minutes, barring problems. (I've had plenty of problems, but most of them have been due to bad fabrication on my part.)

There are many ways to make an oil burner. The backyard metal casters are all over it. See backyardmetalcasting.com for more ideas. I like this one because it's simple and it doesn't require compressed air or especially clean fuel.
   Matt B - Thursday, 07/26/07 22:18:52 EDT

Oil Forge/Furnaces. See the Chastain book reviews on our Bookshelf. Some preheat with propane for a short while then dump in the oil.
   - guru - Thursday, 07/26/07 22:53:22 EDT

Thanks, Matt!

We'll talk more about it whenyou get back from vacation, but that gives me the idea.

Enjoy your vacation!
   vicopper - Friday, 07/27/07 09:23:26 EDT


We always do. Thanks!

If you have access to plenty of free waste veggie oil, I think an oil burning forge could be a really good deal. If you have to buy diesel, home heating oil, kerosene or the like, I'm not sure how the math works out. I'm only a hobbyist, so I don't burn that much fuel. There's a cafe with a deep fryer on the ground floor of the building where I work. I have an arrangement with the manager, and that one fryer provides most of my fuel. A full-time smith might have a harder time getting enough free oil to keep his forge running.

I've burnt used crankcase oil in mine, but only as an experiment. It worked great. (I've read that waste moro oil is very energy dense.) WMO might be easier to come by in the necessary quantities. But I'm not sure it's safe on a long-term basis, I'm not sure it's environmentally sound, and I'm not sure of the legalities. You'd have to look into all that.
   Matt B - Friday, 07/27/07 14:27:50 EDT

Note: "moro" = "motor."
   Matt B - Friday, 07/27/07 14:37:45 EDT

Hi, Tyler
Your post takes me back to when I was 14; using my parents fireplace with a hair dryer. The only part of my face that wasn't black were my teeth behind my smile. It may not be the most efficient method, but it might work. Be careful of moisture in the flowerpot. I am not sure what you mean by "Christmas tin". Are you using last year's fruitcake for an anvil?
   Paul - Friday, 07/27/07 14:59:29 EDT

Having melted a terracotta flowerpot in my forge I would advise caution as well. (trying to use the forge as a heat source for enamelling)

   Thomas P - Friday, 07/27/07 15:23:14 EDT

Ceramics and Forges: There is a big difference in clay firing and melting points. We fired lots of clay tesserae for making mosaics in my gas forge. You had to watch them carefully. After reaching a little over red they melted then boiled making clay foam. The clay was common ceramic clay slip.

What potters call "stoneware" clay is much higher firing but it is still not in the range of refractory clays used to make firebrick and various refractories.
   - guru - Friday, 07/27/07 15:59:14 EDT

ThomasP, while your imaganation may see the triphammers, what do you physically see?

I like to think that if SWMBO gave me triphammers etc. I would still have the eyesight to use them.
   Ptree - Friday, 07/27/07 18:25:29 EDT

Does anyone know the schedule and places of Clay Spencer's build your own tire hammer workshops? Is their a web site to find this information? thanks in advance
   Jimgepa - Friday, 07/27/07 21:35:27 EDT

Jim, I've not seen a schedule but Clay is a member of NCABANA (North Carolina) and that is where it would most likely be.
   - guru - Friday, 07/27/07 22:14:43 EDT

What are tesserae? I ask because it's an odd word. BUT: dig it: lonnnng ago in math class, we used to make models of A to the 3rd and 4th, and 5th and.... The teacher called these fictional representations tesseracs (sic). Take a piece of coat-hanger sized wire, any length, and call it A. Make a square of four pieces the same size. That's A squared. Now move that keeping the plane parallel through space and connect the corners. That's A cubed. Now move the cube diagonally through space and connect those corners. That stands for A to the fourth. Now twin that and move the whole shebang diagonally out a distance, enough to suggest the movement, and connect those corners. Now you have A to the fifth. By now your're out of clamps and your soldering or brazing skills are pretty well tuned, and you have... ta da!... A to the sixth-- and one helluva baroque wire sculpture. I am going to make a biggie out of conduit some day and put it up on the hill out back and see how long it takes for the neighbors to get me into court. Who knows, maybe it'll pull signals away from Thomas's VLA rig. However, I digress-- any resemblance, Jock?
   Miles Undercut - Friday, 07/27/07 22:50:27 EDT

Tesserae (Latin, plural) are small irregular mosaic tiles as used in old tile mosaics. Size varies according to the size of the mosaic but can be as small as 1/2" or a little less but may be as big as 1" or more. Slip is poured onto a plaster vat (slab) and when leather hard it is cut with a knife into irregular polygons, then dried, glazed and fired.

And you thought all those miles of mosaics in Italy were made from old china or broken tiles? My spelling may be incorrect as it is not an English word.

Mosaics can be made from old tile but the edges can be very sharp and dangerous. Nice glazed tesserae have naturally rounded edges. Yes, a tesserac is derived from the same Latin root (don't ask me how I am not the Latin student, my daughter was).

Your tesserac is an interesting construction. Consider the DNA molecule. It is a spiral because the protein molecules that make it up have a natural kink due to the way the carbon bonds work. It is a natural occurrence of the elements C, H and O and thus carbon based life with DNA will be the rule throughout the Universe. If there is "intelegent design" then this is where it starts.
   - guru - Saturday, 07/28/07 04:24:21 EDT

what is oxidation and how does it affect forging and smelting. I have heard alot about it ,but don't exactly know what it is or its causes and affects.

   troy - Friday, 07/27/07 23:12:38 EDT

Oxidation is the burning (combining with oxygen) of the surface of the steel at elevated temperatures and occurs anywhere above about 300 degrees F starting with temper colors. At a thousand degrees (a very low red) scaling (the creating of a thick blue grey oxide layer) starts to occur. The hotter the steel and the more oxygen in the atmosphere the worse the scale.

Where it gets really nasty is if steel is held at a high temperature for a long time OR if the scale is broken (it is brittle and tend to flake off) by forging and then reheated causing the scale to melt and more scale of different thicknesses to be created. Then continued forging creates a rough textured surface. In some cases this is desirable but in most it is not and ruins the surface of the work.

A good carbon fuel fire will have little oxygen and scaling is greatly reduced IF the steel is kept in the right zone of the fire. Gas forges tend to scale worse than coal and charcoal and electric furnaces are the worst.
   - guru - Saturday, 07/28/07 04:37:03 EDT


It would have been more accurate to say that a good carbon-fuel fire has little *excess* oxygen. Didn't confuse me, but you were answering a pretty basic question . . .
   Mike BR - Saturday, 07/28/07 07:26:48 EDT

Hey . . look at the time I was answering it. .

On the road today moving stuff today. . . load XX of XXX. . .
   - guru - Saturday, 07/28/07 07:56:05 EDT

Jimgepa-you can email Clay @ clayms@brmemc.net to find out his schedule- I understand he just finished a workshop in Pa where he built serial # 258
   - Ray Clontz - Saturday, 07/28/07 11:55:27 EDT

....I always wondered about how steel oxidizes in an electric furnace. What about the coil induction forges like b'sdepot has?
   - Tyler Murch - Saturday, 07/28/07 12:16:33 EDT

Tyler, it's a time/temp/O2 thing so increase any of those and you get more oxidation; decrease any and you have less. The fun is when you change 2 or more of them in various ways and their interactions are not so easy to guess sometimes.

Electric furnace? Like an arc furnace used to melt steel? You get back into fluxes for that or an inert gas cover---or vacuum.

Induction forges do pretty well because the time to heat is so short, scaling is almost all do to the trip to the anvil and back and the hammer time.

So Miles---you want a copy of SETI's greatest hits?
   Thomas P - Saturday, 07/28/07 14:03:21 EDT

Thomas-- Wow! Do I ever! SETI's greatest hits! Yippee! It's free, right? (By the way-- what is a SETI?)
Troy-- Oxidation is what makes rust on steel, puts green frung on old copper, brass and bronze. The oxide gets in the way of conjoining the metal with another metal which is howcum silver, for example, has to be shiny clean to solder it. Same with copper and brass and bronze. Oxidation is oxygen interacting with the molecules of the metal. The metal is delighted because it yearns to return to its natural state, eency particles of itself. Iron is happiest when it is lying in a heap of rusty dusty. I hope this answers your question. If not, don't hesitate to ask again. I found in a lifetime of reporting that the seemingly dumbest questions are often the toughies that make the boffins squirm and produce the most interesting answers.

   Miles Undercut - Saturday, 07/28/07 19:07:18 EDT

A couple things,

Ray, where in PA is this JYH workshop? I'd love to check it out if it's within my driving range (Philly area).

Now, with the oxidation report: why is it that the oxides of certain metals protect the underlying material? For example, the 300 series relies on the surface layer of chromium oxdide to protect the steel. Various grades of titanium oxide can be stronger than anything and withstand immense work duty. So where is the line drawn? Does it rely on specific metals? And Troy, relax man, it's all cool here in the Den, let's keep it that way.
   - Nippulini - Saturday, 07/28/07 20:47:08 EDT

Nip: The hammer workshop was in western Pa. The problem with iron oxide [rust] is it isn't stable, as You know it never sleeps. Anodizing is an oxide treatment on aluminum that I am sure You are aware of, and being stable and hard it is usefull, the type 3 hardcoat in particular. Why some are stable and others not, more to the point of Yopur question has escaped Me, if I ever did know it.
   - Dave Boyer - Saturday, 07/28/07 22:15:08 EDT

Troy-- Opinons do not enter into it. Oxidation is not a subjective topic. It is what it is.
   Miles Undercut - Sunday, 07/29/07 01:10:04 EDT

I am working on plans for my first cole forge, and i am trying to find out what kind of blower i need. It will be a brick and steel sidedraft forge, I made my firepot out of 5/8" steel roughlya 10 1/2"x10 1/2" square 5" deep with 1 1/2" tuyere and a 2" dia disk of 1/4" steel with 5 1/4" holes drilled in it welded 1/4" above the tuyere. I am looking for advice on how many CFM I need to move to feed my forge. Any advice on what I should look for, and advice on forge design would be greatly appreciated
   steeltoe - Sunday, 07/29/07 03:31:38 EDT

Steeltoe, The blower size varies with the forge and work size. The necessary CFM varies between 150 and 500 (small to very large blacksmith's forge). For the effort you are putting into this forge you should purchase a good forge blower from BlacksmithsDepot or Centaur Forge. I think the imported blowers sold by BlacksmithsDepot are better as they are designed specifically for this purpose.
   - guru - Sunday, 07/29/07 08:24:42 EDT

Stable Oxides: Nip, I think Dave covered the stable oxides thing. Generally the harder something is to oxidize the more stable the oxide and the longer lasting. In the case of your stainless it is a very thin layer. It is NOT the same as the scale that forms when heating stainless to forge and flakes off just like common steel scale. The variations in strength are chemistry and physics and are what they are. If it all made sense the would be no mystery in life and no need for religion.

Why is aluminium oxide as a crystal (saphire) as valuable for its beauty as diamond, sought after, collected and protected and both used to make common grinding wheels, disks and belts that we use for a while then throw away? Why do blacksmiths burn something just a step away from diamond as fuel?

Why do gold, silver and copper resist oxidation while a close relative lead oxidizes rapidly? Why does magnesium easily burst into flame while aluminium (which is very similar) does not. Why does zirconium which is nearly as dense as steel let neutron radiation pass easily ans steel does not? Why is it that I have not heard of the new controversy that says Earth is not part of the Milky Way but anothe galaxy colliding with it?

Science answers pieces of these questions but the rest are the mystery's of the Universe. . .
   - guru - Sunday, 07/29/07 08:51:07 EDT

ThomassP In induction heating the low scale factor is indeed due to the short heat time. However one does see scaling in the coil, unless there is a protective atmosphere. One item of note, the scale is conductive, and needs to be blown out of the coil if the coil design allows buildup. It will alter the field, and can short out the coil. In industry where large billets are heated, the heat times get longer to allow heating to the core, and scaling can be an issue. The bigger the billet the lower the frequency used and the greater the issues with heating of stuff around the coil as well. We had to be very careful about things like handrails made of steel close to coils. I have seen the paint blister on handrails about 6' from a big billet heater coil. The handrail is heated from the field. We would put very large low Ohm resisters to ground to bleed the energy from the rails. We also had to be careful as to bolting on the coils etc. We usually used 316 SS bolting, but when torgued, the 316 bolts became slightly magnetic and would heat to melting in somecases.
   Ptree - Sunday, 07/29/07 09:24:12 EDT

The divergent properties of similar metals is due to the differences in the valence electron configuration of the various metals. A study of the periodic chart of the elements will either blow your mind or give you religion. One element is separated from its neighbor by only one electron (and matching configuration in the nucleus). Add or subtract that electron and you get another element with different properties. Utterly amazing to me.
   quenchcrack - Sunday, 07/29/07 09:49:29 EDT

I apoligize for my behavior.
   troy - Sunday, 07/29/07 14:42:52 EDT

troy-- Fret not. What I want to know is, if this alleged universe that the estimable Guruissimo refers to began with the Big Bang, and so one would imagine there was no universe for things to explode in before that... then where, exactly, was it that this Big Bang went boom? Hmmm?
   Miles Undercut - Sunday, 07/29/07 15:44:37 EDT

Miles, If there is a big bang in a place where there is no universe would anyone hear it?
   Ptree - Sunday, 07/29/07 17:05:22 EDT

In the infinite randomness of bistro mathics of the Universe that preceded the current Universe. In other words __it happens.
   - guru - Sunday, 07/29/07 17:10:53 EDT

Metals, smetels. . ask why Ebony is black as coal and Dogwood is pink and nearly as hard? Why is Southern Yellow Pine soft but stronger than oak? Why do my most important tools rust and the least important seem rust proof?
   - guru - Sunday, 07/29/07 17:15:07 EDT

Miles, the big bang contained not only all the matter in the universe, it contained all the empty space. THAT is what is so hard to get your head around. The big bang was the origin of EVERYTHING. It expanded into nothing. Of course, I personally believe that the universe sits on the back of a huge turtle.
   quenchcrack - Sunday, 07/29/07 18:36:13 EDT

answers to great ponderable questions. I like Lucy Van Pelt's answer to these type questions "BECAUSE IT IS!"
   JimG - Sunday, 07/29/07 20:08:21 EDT

You know.. I am off-line for a couple of days and I come back to find a discussion of the creation of the universe... that doesn't really surprise me... What does surprise me is that no one suggested a really Big Old Blacksmith forged it :D
Just adding to the insanity,
   Daarian - Sunday, 07/29/07 20:57:26 EDT

dont blacksmiths burn something a step away from diamond as fuel because that step takes millions of years? (under normal conditions)

and doesn't powdered aluminum and iron rust burn rather hotly when it is eventually ignited?
   - newbiesmith - Sunday, 07/29/07 21:24:57 EDT

   - Dave Boyer - Sunday, 07/29/07 22:58:07 EDT

Is it correct that cast Iron that cools slowly turns into black Iron with graphite as a alotroph of carbon instead of cementite? Why is this? And how slow is slow?
   troy - Sunday, 07/29/07 23:26:58 EDT

Has anyone heard of a oil/water furnace?
I read in a survival book that if you set up something so that you have and equal amount of water and oil driping into a fire that that is the hottest type of fire, and very efficient.

Also, can hydrogen be used as a heat source for forging, I know there used to be hygdogen torches before oxy/acetylene.
Any info on that?

(Thanks Matt for the info on your oil forge!)


   Hayes - Sunday, 07/29/07 23:39:46 EDT

quenchcrack-- and as the little old lady said, it's turles all the way down.
   Miles Undercut - Monday, 07/30/07 00:16:21 EDT

Actually, Daarian, my ancestors, the Finns, have just such a theory- that a blacksmith is pretty much responsible for it all.
Do a little research on the Kalevala.
   - ries - Monday, 07/30/07 00:31:40 EDT

Jimgepa, Clay is in the process of moving to Somerville, Al. starting this week. The move, building a new shop, etc, will keep him "tied up for a while". His new e-mail will be tirehammerman@tirehammer.com and he will have a tirehammer.com website hopefully in the near future.
   Ron Childers - Monday, 07/30/07 07:37:33 EDT

If you can truly get your brain to accept infinity as a philosophical value and that everything else is infinitely less then you might be able to start pondering "the imponderable"
   - guru - Monday, 07/30/07 07:49:15 EDT

Oil/water: Hayes, It may make a lot of steam and warm you faster (assuming you do not have a proper vent and are breathing all the noxious fumes) but the fire temperature will be lowered by the energy required to evaporate the water (just like burning green wood, wet fuel). In a survival situation where you NEED the heat during freezing temperatures the water may freeze followed shortly by you if its in your fuel lines. . Like the old saying "keep your powder dry", keep your fuel dry as well.

Hydrogen fire is currently quite expensive. Yes you COULD heat steel with it. However, there are two problems. It burns VERY hot and tends to burn the steel and as a non-carbon based fuel it may not form a protective atmosphere to reduce oxidation. The advantage of carbon based fuels is they just happen to burn at JUST the right temperature and create a protective covering the reduces decarburization.
   - guru - Monday, 07/30/07 08:13:32 EDT

And prior to light, heat, and motion, there would be nothing to measure against, regarding time. ┬┐Que no?
   - Time non-existant - Monday, 07/30/07 08:25:19 EDT

The time post was sent by me.
   Frank Turley - Monday, 07/30/07 08:28:33 EDT

Reis, I really like the notion of a blacksmith starting it all. I will indeed do the search.
   ptree - Monday, 07/30/07 08:51:52 EDT

The energy of the cosmic hammer striking the cosmic anvil with the seed of the know universe, a singularity, between causes the big bang and everything else thereafter. Thus intelligent design is by the original blacksmith. It follows that intelligent life will exist only where eons of swampy conditions and a cooling, shrinking planet has created coal in order that the smiths of those worlds can create technology and ponder the original smith at the speed of light. . .
   - guru - Monday, 07/30/07 10:32:22 EDT

Well, glad we're unscrewing the inscrutible at last. Hey, Ptree, can you use Molykote on the inscrutible to keep it from siezing?
   Alan-L - Monday, 07/30/07 10:36:12 EDT

SETI: Search for Extra Terrestial Intelligence or years worth of hearing "the music of the stars" hunting for a signal.

I figured that as soon as the folks out there got our broadcasts of the Three Stooges and Gilligan's Island they put a radio silence quarentine on our section of space.

Remember that iron itself is just old star poop; personally I'm more concerned by how we will end than how we began having a bit more control over that...

Oxides: there are adherent oxides and un-adherent oxides. If an oxide holds tight and does not pass O2 then it protects the surface. If it doesn't hold tight and or passes O2 through it then it will fall/get pushed off and the oxidation will proceed into the mass. Note that stainless will rust unless the surface is treated to remove free iron leaving only the compounds with adherent oxides.

Cast iron: under perfect conditions one should be able to grow perfect crystals out of a melt; but this is usually a very slow and expensive proposition---I have seen crystals grown under multimillion year cooling rates; ver impressive but not to useful to try to duplicate in the lab.

Ptree, note that I had mentioned inert gas and vacuum WRT heating.

   Thomas P - Monday, 07/30/07 11:22:17 EDT

"Is it correct that cast Iron that cools slowly turns into black Iron with graphite as a alotroph of carbon instead of cementite? Why is this? And how slow is slow?"

No. Cast iron is on the hypereutectoid side of the phase diagram. That means that there is more carbon in the melt than can be dissolved by the iron or exist as cementite. It will pretty much always be cast iron with graphitic carbon as flakes or nodules. However, this questions reeks of "homework" so you better research my answer carefully before you turn it in. :-)
   quenchcrack - Monday, 07/30/07 12:38:39 EDT

Nippulini - the tire hammer workshop was near Titusville, PA. 22 tirehammers produced & yes he said that brought the total to 258, anvil made out of 7 & 1/2" rounds. Clay figured weight for the hammers at about 1000 lbs versus more around 750 for the typical hammer he produced. The workshop was the 13th, 14th, & 15th of July. My hammer was #10 of the 22.

QC - re: turtles - all I can say is Wizzard! (Good series.)

Induction heating - oh you mean the furnace we use to melt tool steel, monel, Co-6, Co-25, Nickel-X, 300, 400, & PH grades of stainless, hastelloy, etc.

Ptree - The Kalevala (translated into English) was a good read. There was a fantasy-sf series in the 1970's that was loosely based on stories from the Kalevala. I think the author's name was Emil Petaja
   - Gavainh - Monday, 07/30/07 17:32:34 EDT

ThomasP, i saw inert gases in the mention of melt, but the forge was supposed to oxidize in the trip to the anvil:)
   ptree - Monday, 07/30/07 20:21:42 EDT

I have a doubble bitted axe that I found. It is badly pitted so there is no chance of finding a name but some light grinding near the handle hole reveals it is layered steel. (damascus) Given the location I found it (family farm) I beleve it to be at least 90 yrs. old. What im wandering is if you could tell me when axe factories began stamping axes instead of layering and hand forgeing.Any info on this matter would be greatly appreciated. Also the axe is a third heavier than an axe of the same size.
   daniel - Monday, 07/30/07 23:02:02 EDT

Thomas-- Yo! A copy of SETI's greatest hits sounds grrrrooovy, baby! Send it! Does it come with an autographed picture of Jody Foster?
   Miles Undercut - Monday, 07/30/07 23:18:24 EDT

What is my best source of information on how to use a thermic lance please?
   - philip in china - Tuesday, 07/31/07 04:11:14 EDT


The chances of an axe being Damascus steel are slim to none, I'd think. Much more likely that it is made of wrought iron, with a steeled bit. That was a common method of making axes in the days before steel became chea and plentiful. One of our historians will likely be able to tell you about when that change occurred.
   vicopper - Tuesday, 07/31/07 07:53:25 EDT

Oxygen Lance: Phillip, My welding book has a paragraph on them. . Basically it says heat the edge of the work to be cut and the end of the lance tube are heated until a yellow heat and then you turn on the oxygen. . . I don't think you need to heat the work but it is more efficient. Castings a foot thick or more are cut with them and they will cut through rock as well. I THINK the ones for cutting rock have a flux coating. Those for heavy castings are just a piece of black iron pipe. Air-arc cutting torches work on a similar principal except they use the high heat created by the arc and cheaper air.

Supplies and How-To:

   - guru - Tuesday, 07/31/07 08:14:57 EDT

Guru, another good anvil find... I think... I purchased a large anvil about 160 pounds from a closing factory only thru pics. after picking it up it appeared homemade, i scraped about 10 layers of old paint and revealed a arm and a hammer logo along with the text in super condition. could you help determine value.
   tbody321 - Tuesday, 07/31/07 08:34:58 EDT


I agree with vicopper's response.

Henry C. Mercer researched early American axes as part of his book, "Ancient Carpenters' Tools." The book was first published in 1929. The single bitted axe was the common axe used until relatively recent times. On page 11 of his book, he shows a photo of three double bitted axes from his collection: "Fig. 10 The Double-Bitted Axe." The caption follows. "The three factory-made specimens here shown come from Bucks Co. Pa. and illustrate a comparatively modern 19th-century tool of the lumberman rather than the carpenter. They were used in extensive forest felling, where, minus a grindstone, they kept sharp twice as long as the single-bitted axe. The handle had to be straight, so as to work both ways."
   Frank Turley - Tuesday, 07/31/07 09:23:35 EDT

Daniel, both Vicopper and Frank are correct. The closest you can get to the transition from steeled wrought to stamped monosteel date without knowing what factory produced the axe is somewhere in the last half of the 19th century, say 1860s to 1890-ish. That goes for American axes in general, and as Frank pointed out the double-bit is a late addition to the toolkit. It does not appear in either of the pre-1860 tool catalogs I have.
   Alan-L - Tuesday, 07/31/07 10:31:23 EDT

One thing people forget is that there a lot of "factory smiths" out there producing items---just because it may be hand forged does not preclude it being made in a 19th century factory. Union Hoe company ran a hand forging operation into the 1990's in Columbus OH.

tbody321; if the arm and hammer are stamped into the anvil it is an Arm & Hammer anvil made in their factory in Columbus OH. Price will generally range from scrap price to around US$3 a pound with almost a factor of 2 depending on condition and your location---which you don't provide much info on.

If the arm and hammer are raised from the surface of the anvil it is a Vulcan, cast iron with a steel face, and the worth is about 1/2 to 2/3 that of a Arm & Hammer anvil and falls off rapidly with flaws in the condition.

   Thomas P - Tuesday, 07/31/07 12:25:00 EDT

Hand Forged and "Factory" Today there are many smiths in little one man or a few more shops that produce all kinds of tools. A man with a power hammer, a press, grinder and a few other tools can produce a significant line of tools. Bruce Wallace produces a variety of tools for a hardware retailer and tongs for a larger forge shop. Big BLU manufacturers forged hammers, punches and drifts as well as power hammers. Quite a number of micro forges and not so small forges are making tools for the blacksmithing community. Then there are the smiths that make various decorative iron items in production. Just because you are small doesn't mean your operation is not a "factory".

   - guru - Tuesday, 07/31/07 19:30:29 EDT

Axes. My 1894 catalog shows one double bitted axe for sale alongside two single bitted axes.
   Frank Turley - Tuesday, 07/31/07 20:04:53 EDT

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