MattBower

FWIW, a traditional vermiculite or wood ash anneal from well above critical, with steels like O1 and 1095 (in the .85%+ carbon range), can cause problems. Given sufficient time as austenite, the carbon will tend to clump up into big, nasty carbides that can make drilling and filing a real bear. Go to any bladesmithing site -- probably including this one -- and search the archives, and you'll find plenty of guys wondering why they're ruining drill bits on "annealed" 1095, O1, etc. It's because they used the old-fashioned, slow-cool anneal from well above critical, and formed big, highly wear-resistant carbides in the steel. (It's probably worse in 1095, because there are fewer alloying elements in the steel to keep the carbon from moving around, compared to O1 and other tool steels. Regardless, big carbides also aren't necessarily good for the blade if you don't get rid of them before or during the final heat treatment, which isn't the simplest thing to do.) If you notice the recommended annealing temp for O1 at the link Frank provided, above, it tops out just barely inside the recommended hardening range. There's a reason for that. One of my earliest blades was made from O1, and despite repeated tempering cycles at increasing temperatures, I had a really difficult time sharpening it. Not that it wouldn't get sharp; it just took an incredibly long time -- I'm talking many hours -- with my coarsest stone to get it to start coming around. (And no, the edge I started with wasn't all that thick.) I now suspect that was at least partly the result of bad heat treating practice that left the steel chock full of great big carbides. What I'm saying, essentially, is to be very careful when you're annealing high carbon steels, or you could end up making matters worse. A better solution than the traditional anneal is a sub-critical anneal or spheroidizing anneal, but that's not so easy with very simple equipment. http://www.steeluniv...g/3630-0050.htm

Sure, ceramic would do for melting and impact. It's the surviving the launch part that might be a little hairy -- your slow, constant acceleration observation is dead on. A trebuchet might be the thing. You're right that just chucking it into a lake probably wouldn't be very exciting. I have some thoughts about what might make it exciting, but maybe I shouldn't plant ideas in the head of every teenager who wanders by this thread. (I say this as a guy who spent his share of time as a teen making napalm, striving to make ever-larger firecrackers with black powder, playing with an O/A torch when no one was looking, and just generally doing some things that, in retrospect, may not have been great ideas.)

I have ordered puzzles from these guys, who sell tavern puzzles among many other kinds. http://puzzlemaster.ca/ I've often thought that these would be fun smithing projects, but the tolerances have to be pretty tight on some of them, and without instructions I can imagine spending a lot of time trying to get everything just right. It could be especially problematic if you didn't already know how to solve the puzzle before you set out to make it!

"Almost yellow" in sunlight is probably too hot. The traditional blacksmiths' color descriptions seem to assume a relatively dim shop, at least in the immediate area of the forge. Was the steel sparking when you pulled it from the fire?

Thomas makes a good point about hot filing or rasping. It works very well. Not as well as a good grinder, but many of us don't have good grinders. :)

I took him to be saying that he started with more material than he needed for a blade of the size he wanted, and needed to cut it down to size in order to begin forging -- or perhaps during forging, after he realized he'd started with too big a blank.

Try water hardening again. Make sure you get it to a shade above non-magnetic (non-mag is 1414 F, and I want you to shoot for 1500-1550 F for the quench), and get it out of the fire and into the quenchant in a second or so -- no fooling around in between. If that doesn't make it skate a file, then it's probably just too low in carbon to get really hard. The brittleness you're experiencing indicates some hardening, but it could also be related to large grain size from overheating. Normalize two or three times prior to hardening to reduce the grain.

A cutoff hardy will work, but I prefer a hot cutter. Some other options: hacksaw, band saw, or angle grinder with cutting disk. A bench grinder can be useful for refining the profile, if you don't have a belt grinder. Edit: Oh, yeah -- files! Can't forget good files.

I almost suggested written instructions on how to post the vid, left with someone who won't be present for the event. You know . . . just in case. Of course that doesn't mean that some little part of my brain hasn't spent the last few hours wondering what kind of container you could use to launch molten Al from a trebuchet. It'd have to be able to completely contain the molten metal (spillage seems like it'd be a bad thing) and survive the shock of launch, but break open on impact. Or at least that's my vision. :ph34r:

I have used boric acid as an anti-scale for heat treating. Make an alcohol-boric solution, paint it on, and let the alcohol evaporate. The resulting boric coating is somewhat fragile, so treat it gently until the boric melts in the forge. I was pleased with the results, although I've only used it a couple times. Boric acid starts to attack steel around 1600 F, so it wouldn't be any good for high alloy tool steels or stainless steels that harden well above that temp.

I got out a year before you. I wouldn't have trusted those PASGT flaks to stop any bullet you'd encounter on a modern battlefield, despite the rumors that went around about them. But a blade flung by a buffer? Might not stop it entirely, but I suspect it'd limit penetration quite a bit. Still, this would be an excellent excuse to make and wear a real, functional chain mail hauberk. lol

Somebody be sure to shoot video of that!

If you're saying the steel crumbled when you hit it, you may have overheated it. Welding temp varies inversely with carbon content (more carbon = lower welding temp), and some steels don't respond well to being forged outside a narrow range. When you say the steel was at "almost" a yellow color, what kind of ambient light are we talking about? Dimly lit shop? Bright sunlight? It makes a tremendous difference.

Welcome aboard, Dan, and thanks for what looks like the most valuable first post that I have ever seen on this or any forum! There's also a good backyard foundry tutorial at AlloyAvenue.com (formerly the Backyardmetalcasting.com forums): http://www.alloyaven...y-Tutorial-Book I don't know if you've seen that one. A source of reasonably priced crucibles is Legend, Inc.: http://www.lmine.com/mm5/merchant.mvc?Screen=CTGY&Category_Code=crucibles I have Colin Peck's book. I built a forge based on his burner design. It was waaay overpowered. :)

If you do that, be sure it's marked as pewter. I bought a "pewter" mug to have a source of pewter for casting, only to discover that it did not melt like pewter. I'm guessing it's some sort of Al alloy.

Yeah, that seemed pretty weak. It's kind of like leaving the waiter a tip of twenty-four cents . . . in pennies.

Didn't see it, but I knew he'd gotten into blacksmithing. He showed up here a couple years ago asking questions about a big Nazel power hammer he had bought.

That guy -- the Chinese iron-flinger -- is nuts!

Clearly those guys didn't have adequate training, but I'd expect whoever set up the lab (and I'm sure it wasn't them) to know a little better.

I've thought about buying an old flak jacket to wear while buffing and grinding. Seems like it might be overkill . . . but then again . . .

I'm not sure what's burning, but it looks like they may have a metal plate about 1/4" thick on the part of the bench where they're working, although even that doesn't seem adequate to me. You can see a square, gray, metallic looking, plate, roughly 2'x2', sitting on the bench in the closeup right before the eruption. The ingot mold seems to be on top of it. Again, that still doesn't seem like enough to me. That mold will get hot, and so will the plate.

I wouldn't expect that it would take much tin to put a wash on a pot. If you have a store nearby that sells stained glass supplies, you can buy ammonium chloride (sal ammoniac) there. I'm pretty sure you can buy tin cheaper than that McMaster link has it -- although it certainly won't be cheap, even at the best possible price. McMaster's prices are pretty high on a lot of items -- which in my view is justified by the fact that you'll probably get your order tomorrow. I used to have contact info for a guy who was selling tin at much more reasonable prices than most. I'll try to dig it up.

Ah, I didn't see your added comment about blades. That does indeed make a difference. If you're interested in forging blades, the list gets even smaller -- although it's still pretty lengthy. Dr. Hrisoulas' books are excellent resources.

I agree completely, Thomas, and that's a worthwhile point to make for the sake of any casual Internet surfers who might happen upon this thread, read it less-than-carefully, and draw the wrong conclusions. But to be clear, I think the original poster's question was not, "where can I find junkyard steel of type X?" Junkyard steel charts are very problematic for answering that sort of question. However, I believe his question was, "where can I find a reference that tells me what kind of steel would be good for making item Y?" And I think the junkyard steel charts would actually do a fair (if somewhat limited) job of that, although the steels they list for many applications are often much higher-end than what industry typically uses.

No, I don't know of a single, concise resource that contains what you're looking for, although Machinery's Handbook does have a table that suggests steels (often expensive ones) for various applications. That will get you in the ballpark, as will the various junkyard steel charts. But the first step is to start becoming familiar with steel terminology, the basic properties of different types of steel, and then the more common alloys and their specific properties and common uses. Mod note: Link removed at the request of Anvilfire.