MattBower

Good tip. There's a boiler repair place near me that sold me some insulating castable once. I wonder if those guys use ceramic board.

High Temp Tools sells Insboard 2300 by the square foot. http://www.hightemptools.com/inswool.html Ward Burner sells Insboard 2300 and 2600 by the square foot: http://www.wardburner.com/otherproducts/ceramicfiberproducts.html

In theory, you could get 30 or 40 pounds of nails, forge weld them all into one big lump of steel, and forge that into an enormous sword-like object (or even a real sword!), But with very few exceptions, it'd be a pointless waste of time, effort, and a whole lot of frustration.

I backed out of a long post that I had composed earlier today, for more or less the same reason. Look, ramsies, if you want to learn something about metal casting, you'd be well served by reading both of the following links a couple times. They'll give you enough background to be able to start asking good questions, maybe: http://www.iforgeiro...-for-beginners/ http://www.alloyaven...y-Tutorial-Book There are also some excellent books out there, which you can probably get through inter-library loan if your local library doesn't have them. Steve Chastain's stuff is good: http://stephenchastain.com/shop.htm

You could melt aluminum that way. The drum probably wouldn't last all that long. A 55 gallon drum would be vastly oversized for this. I suggest you google "Gingery charcoal foundry" or "flowerpot furnace."

So we're talking typical leaf spring dimensions. The sword you envision would weigh approximately 25 pounds, assuming each leaf is only 30" long -- most I've seen are longer than that. Even allowing for massive scale losses during welding and forging, you're looking at something two or three times as heavy as a real, functional great sword.

It's certainly not impossible. How large is each leaf?

I'd say what Bowie demonstrated at the Sandbar Fight, more than anything else, was a preternatural ability to absorb punishment and keep functioning. :)

Thomas, some of the files I've had tested have run 1.2%-1.3% C! (The modern Nicholsons do appear to be 1095 with a dash of chromium, though.)

That's a good looking first knife. You should be proud of the effort you put into it. However, "carbon steel" from Home Depot is almost certain to be either A36, which may be hardenable in oil if you're very lucky, or 1018, which won't harden in oil at all. If you did manage to harden that blade, put it down to serendipity. I second the advice to get yourself some real blade steel. Heat treating is among the most critical skills to learn if you want to make knives, and practicing on A36 won't teach it to you.

Thomas makes a good point. I am so used to muddling through on my own that I rarely think to recommend finding someone who can coach you through a process. But if you have that opportunity, by all means take it!

I'd say that you're starting exactly where you should: by learning to make simple monosteel blades. Once you have an anvil, start learning to forge monosteel blades, and to make simple forge welds. Then maybe try a little san mai. In the meantime, you can be reading up on pattern welding. Welcome to IFI!

Well, yeah, as I said before, you need to burn at least a gallon of oil an hour. I can see from your flame that you're nowhere even close to that. Just opening up the air, alone, isn't going to help you. You also have to deliver enough fuel to the forge. And you're not. I hate to say this, but I don't know of anyone who has successfully used a Babington design for a serious forge or furnace. They seem really clever in theory, but in practice they're very finicky. I suspect the reason you're having trouble with the flame blowing out is that you have your atomizer ball in the air stream, so at a certain point the blower air is bound to interfere with the drip. Also, I saw some calculations that someone had done a while back, and the amount of oil that you'd have to flow across that tiny hole in order to vaporize a gallon or more an hour just isn't realistic. Did you consider one of the cruder oil burners (such as the "Brute" or "Moya" designs) that rely on gas to preheat the forge, and drip oil directly into the blower air stream just before it enters the forge? They are indeed crude, but they work. Another option would be to buy a siphon nozzle to replace the Babington ball. Like this guy:

I can tell you that the 5000 degree stuff is not what you want for a forge. It's a magnesium oxide-based fireproofing material. Back before I knew any better, I bought a bucket of McMaster's 3000 degree "extreme temperature ready-mixed cement." It seems similar to Mizzou and other dense castables, but why pay to ship water? I don't think they have anything equivalent to ITC-100. Plistix 900 is supposed to have a similar effect at much lower cost, but I've never used it. You can buy it from Wayne Coe and others.

OK, a few observations. First, it looks like your internal dimensions are roughly 6"x6"x15", or 540 cubic inches. Let's round down to 500 for the one "corner" of the interior that's cut off. That's a pretty decent sized forge. Diesel fuel contains in the ballpark of 140,000 BTUs per gallon, or about 36,800 BTU/L. Waste veggie oil contains a bit less. So if you're burning a liter in 2-3 hours, you're probably putting in something less than 12,000-18,000 BTU/hr. Ron Reil says you want about 450 BTUs (per hour) per cubic inch of forge volume to hit welding heat in a presumably well-insulated forge. In a forge of your size that'd be 225,000 BTUs per hour. That seems excessive to me, but the point is that you are not burning nearly enough oil right now. That's why your forge isn't getting hot. You should aim for a gallon per hour to start experimenting, and adjust from there. Second, I notice that your blower is choked way down to a tiny pipe at one point, presumably because that's the size valve you had on hand, or could easily get. That's no good. That's probably why a big flame is smoky: even with the valve wide open, you're probably not pushing enough air into the forge. You still haven't said what sort of blower you have, but even a blower that's designed to deal with high back pressures (most aren't) is likely to struggle with that arrangement. Get rid of that valve and open up the tuyere so it's at least 1.5" pipe from the blower all the way to the forge. You have to let that sucker breathe -- and you're going to need the extra air in order to burn enough oil to get the BTUs you need. You'll have to find another way to control the air flow. I'm a little confused about how your forge is set up. Which side are you accessing your work from? Is it the long side, or the "door" at the opposite end from the burner? Finally, out of curiosity, how are you atomizing your oil? I realize you're using compressed air, but how does the air atomize the oil? What does your spray nozzle look like?

Oh, and once again: how much oil are you using per hour, ballpark? And what are the internal measurements of your forge? Guesstimate if you have to.

If "big flame smokes" that's because you are not adding enough air to keep up with the fuel. Anytime you see or smell smoke, that's a sign that your fire wants more air. You need to make adjustments relatively slowly. Add a little oil until you start to see a bit of smoke; then add a little air. Then add a little more oil, and a little more air, and so on, until you're getting the heat you want. (Making incremental adjustments will also help you avoid flooding the forge.) If the flame you have now isn't heating your forge to the temperatures you want, then yes, a bigger flame would be better. I need to see your setup to understand your question about nozzle size. But if you mean the tuyere, yes, reducing the size of the tuyere will add back pressure to your system, which may be preventing your blower from delivering enough air to burn the amount of oil you want. What sort of blower are you using? A properly tuned oil burner is good at delivering fires-of-Hades temperatures. Most of the homemade burner designs do not run as well at medium temperatures. They tend to want to run near wide open. The amount of radiant heat that comes out of a properly running oil burner can be literally scary.

Oil flames are yellow. It has something to do with particulates in the flame, which incandesce. Don't expect to get a blue flame like propane from an oil burner. It's almost impossible -- and it's not important. WIthout seeing yoursetup, my guess is that you're not delivering enough oil. How large is your forge, and how much oil are you burning per hour? Is your forge smoking? (If it's producing smoke, you aren't providing enough air.)

Yes, there are a few things you should know: (1) HSS is tricky to forge; (2) it's air-hardening; (3) you need a temperature controlled oven (furnace) to HT it properly; (4) it's expensive and brittle, so they do not use HSS for roto-tiller tines

I have to agree that those are the nicest rebar knives I've seen.

Yeah, BBQ regulators won't cut it. You need an adjustable high pressure regulator. You can buy online or maybe get one from a big box store for a deep fryer. 0-30 PSI is probably more than enough for most purposes.

Double post.

I should have clarIfied: koftgari in a method of overlay, not inlay. It's more of an Asian and Middle Eastern technique. I don't think the Norse used it. I could be wrong.

Yes, of course 1.167". Sorry!

Those charts aren't worth the pixels on your screen, unless your chart happens to come from the manufacturer of your particular blade. In steels above about 0.85% C, a slow-cool anneal from well above critical can be counterproductive because promotes formation of large carbides that can be extremely wear-resistant (and thus hard to drill). I don't know if that's your problem, but it's one fairly common problem. I've written about this here before.