MattBower

I agree, Steve. That's why I told him to temper unless he wants an unsharpenable blade with a chippy edge. Migration does happen fairly fast, but it's not as big a deal in san mai where you have relatively thick layers and you're not folding and welding repeatedly. WIth an acid etch, you can often see the carbon "transition zone" along the weld seam.

This is good stuff. Thanks for posting. But your shop is way too clean and organized. ;)

I don't know. Probably. Ultimately the thing to do is test some post-tempering blades to see if you need to adjust your process. The temperature is less important than the effect, especially since you're using mystery steel. One thing I can tell you is that home oven temperatures are not very stable; they can swing pretty wildly. My best advice on dealing with that is to preheat an aluminum roaster pan full of sand, and bury the blade in that for tempering. The thermal mass of the sand will tend to even out the temperature swings.

I would flatten that out and establish the bevels with drawfiling, as Rich suggested, then move to abrasive paper or stones. For filing, my usual method has been to clamp the blade to a piece of angle iron in the vise. The problem is that you then have to work around the clamps, and you also have to support the blade so that it doesn't flex during filing. Just recently I tried something new, which I'll call UFMTM("Universal Fixturing Material"). A couple small, properly placed chunks of UFMTMwill secure the blade to the angle iron and give you free access to the entire upper surface, as well as keeping the blade from flexing. A little heat from a torch will break the bond, and scraping/sanding will remove the residue. (Do the heating part outside.) It is a little slower than clamps (takes an hour or so to cure), but I can live with that. I don't work that fast anyway. I probably wouldn't do this during the fine finishing phase, because the residue on the blade can be fairly tenacious and it might be a pain to clean up with fine abrasives. But for coarse filing this seems to be working pretty well.

Well, the 1912 Sears catalog lists Peter Wrights above 85 pounds at 10.5 cents per pound, so $26.25 for a roughly 250-pounder. Depending on what basis for comparison you choose, that's something like $2500-$3700 in 2009 dollars. A brand-new Nimba that size costs $1650. A 275 pound Peddinghaus is $1730 from Kayne & Son. A 275 pound Refflinghaus is $2400, and that's about as expensive as it gets.

He means san mai construction. Forge welded envelope of low-carbon steel around a high carbon core.

Or why didn't this piece get as hard as I expected? Is it because I used a too-slow quenchant, because the carbon is low, because I over-normalized, or because it needs to soak for a while at the austenitizng temperature in order to get the carbon fully into solution? And so on, and so forth. Knowing what you have helps eliminate a lot of variables.

I don't know anything about steel prices in South Africa, but I can get five feet of 1/4"x1-1/2" 1080 from Admiral Steel for around $20, and I'll know with pretty good certainty what I have and what condition it is in. Then I can look up (if need be) how to heat treat it properly, without having to guess at what it is. And I can make quite a few knives from that. The thing is, learning to heat treat well -- if you choose to do your own heat treating -- is a huge part of making good knives. And as long as you're rolling the dice with regard to what steel you have, you're also rolling the dice as far as proper heat treating. It's harder to learn that way. Did it crack because I overheated it, or because of a mechanical flaw that it incurred in its former life as a spring? Or was it because I used the wrong quenchant for this steel?

Only if you want it to be virtually unsharpenable with hand tools, and prone to chipping along the edge. If you've never had the pleasure of working on something well over RC 60 with a stone, it's a treat!

Wow. In my (admittedly rather uninformed) opinion, that's art! I'd be proud to have it on my mantle, and even prouder if I'd made it.

The part about melting the copper to puddles surprises me; copper generally doesn't behave very well when it's molten. Regardless, though, that's nice work, and I love the fact that you were able to make it work with what you had. The only reservation I have about using this piece as a wedding bands is that copper alloys generally don't make great jewelry; they turn your skin green. (I made a quarter mokume cross for my second oldest, and she complained about that.) Do you have a plan for that?

Note: I do not bother with annealing. For the simple steels I use, I find the normalized condition adequate for stock removal. And in steels with greater than about 0.8-0.85% carbon content, the traditional overnight anneal in wood ash, vermiculite, etc., can cause problems.

My process goes roughly like this: (1) Forge as close to shape as I can get it, bearing in mind that my hammer control is mediocre, and that I still often end up with deeper scale pits than I'd like --or than I would've predicted from looking at the forged blade. Finish with a normalizing cycle or two after forging. In the simple steels I use, normalizing means "heat slightly above critical and allow to air cool into black." (2) De-scale using ferric chloride (fast, somewhat hazardous) or vinegar (slower, quite safe), abrasives, or some combination of these. (Lately it's usually a few minutes in ferric chloride, followed by a scrub in hot, soapy water with a Scotchbrite pad.) (3) Stock removal to refine shape, using a combination of grinders, files, stones and/or sandpaper, up to about 220 grit. (I don't go much higher than that because the heat treating process is likely to cause a few scars on the blade, at least the way I heat treat.) I leave the edge of the blade at least the thickness of a dime prior to quenching. The thinner the edge, the more prone it'll be to crack. On the other hand, stock removal on a hardened blade with hand tools -- which are mostly what I use -- is truly no fun, and the thicker the edge the more stock removal you'll have to do. So you try to find a reasonable compromise. (4) Normalize a couple more times to remove residual stresses from stock removal, straightening as necessary during the process. (Stock removal can leave a surprising amount of stress built up in the steel.) (5) Apply clay & allow to dry (if applicable). In some cases I've been known to apply a homemade anti-scale compound (basically a boric acid paste). I have never tried to combine the two (clay & anti-scale). (5) Harden. For me, this generally means quenching in a fast oil (Parks 50) from 1500 F, as close as I can gauge it. Your process will depend on your steel. (6) Temper immediately at an appropriate temperature for the steel and the intended use of the blade. I typically temper twice, for an hour each cycle. Because I temper in the kitchen oven, whereas I do most of my forging half an hour from home, I often do a flash temper cycle with the forge (spine down, watching the temper colors run) or with a propane torch immediately after quenching. That really isn't ideal, but I'm extremely paranoid about leaving a blade sitting around full hard any longer than I absolutely have to. Even if a blade survives the quench, it can crack spontaneously minutes or hours later, if it isn't tempered. Martensite formation causes a lot of internal stress in high carbon steels, particularly ones that aren't very deep-hardening. So, to me, an untempered blade is like a ticking time bomb -- but no one knows how much time is on the clock. I want to get it "defused" as soon as possible. (7) Go back to work with stones, sandpaper, and potentially other abrasives (buffing compound, pumice in oil, etc.), to the desired finish. This is by far the most miserable part of the process for me. Wrap the blade in masking tape (I sometimes used duct tape -- whatever I have on hand) to protect it during the next step. (8) Form and attach fittings, handle, etc. (9) Remove protective covering and sharpen blade. (10) Make sheath.

I don't trust myself to forge them in, especially on both sides of a blade. My hammer control isn't that good, although you could certainly make something along the lines of a guillotine tool to do it. I have used scrapers, and they do a surprisingly quick job of it -- depending on the size and depth of the fuller you want. (And old file can make an excellent scraper.) I made a very simple one, based on this one by Alan Longmire, out of barely-tempered O1: http://forums.dfoggknives.com/uploads/post-510-1169572794.jpg http://forums.dfoggknives.com/uploads/post-510-1169572685.jpg Obviously, that's not a very flexible design. Tai Goo made kind of an intermediate version: http://img.photobucket.com/albums/v453/taigoo/fulleringtools.jpg

Grant, I've seen a couple charts in different engineering/metallurgy texts that say 0.3% C can reach 54-55 RC. To me that seems a little hard to believe in the real world (outside of something like H13, with really high alloy content), which is why I hedged my bets a bit.

Nice!

Mix up some 10% brine, or Superquench if you're feeling ambitious, and re-HT using that as your quenchant. The theoretical maximum should be over RC 50, but you'l need a very severe quench to get anywhere near that.

Good idea. Thanks!

So you're bound and determined to go with gas, huh? I think that may be a mistake for someone with a budget as limited as yours seems to be, but so be it. It'd be helpful to know what tools you have. Drill press? Electric hand drill? Do you have a variety of bits? Do you have access to any taps? Flaring tool for copper tubing? Here's a good thread. http://www.iforgeiro...-and-made-this/ Please remember that propane is very flammable, and heavier than air (so it will collect in low spots). Leaks can be dangerous. It'd be a great idea to get an adult involved in this project.

Well I got a replacement pin vise from McMaster (they told me to just throw away the first one, but I think I'll use it as a handle for needle files), and just drilled a #70 hole through a nickel silver key for a car I no longer own. Took a while, but I think this'll do just fine for my current purposes. Thanks for the advice, folks.

Correction: I just looked at a couple metallurgy texts, and process annealing is something else.

That's how you normalize most simple steels. (I believe the metallurgy texts often refer to this as process annealing, so I don't think you're entirely wrong to call it annealing. But that's not what most smiths think of when they use the word annealing.) Annealing, in carbon steels up to about 0.8% carbon content, usually involves heating above "critical" and very slow cooling from that temp, often in a container of wood ash, vermiculite, etc. (That method can cause problems on steel with more carbon than about 0.8%.) Non-ferrous metals such as silver and copper are often annealed by heating to a high temp and quenching. And in this respect stainless behaves more like non-ferrous stuff than it does steel.

I'm thinking those might be splitting mauls. Same principle, though. That's quite a forge they have.

I've only done quarter mokume a couple times, and I just degreased with alcohol, then applied flux paste. Most of mine were clean and new, and on this I didn't bother with a more aggressive cleaning. I may have taken a Cratex wheel in a Dremel clone to one or two that needed it, prior to degreasing.

Propane is indeed propane. In a gas tight propane cylinder, the pressure depends on the temperature of the LP, not the size of the cylinder. So I can't see why running the torch off a BBQ cylinder would be any more of a problem (besides the fittings issue) than running it off a 1 lb. bottle. Those little torches may not even be designed to run properly on lower pressure, regulated propane. Might as well at least try it.