MattBower

Ordinary sunglasses? I don't know. But you can buy clip-on shade 3 lenses from the link I provided above.

Gas forges generally aren't cheap (at least not by my standards of "cheap"), and they're even less so if you buy a commercially made forge. Making your own is the budget route. There's lots of info about this in the archives here, but as far as finding someone local, try getting in touch with the Florida Artist Blacksmith Association: http://www.blacksmithing.org/

They have no protective value for IR, which is what your forge puts off. There seems to be evidence that long-term exposure to IR can cause cataracts, and that blacksmiths, glassworkers, and others who work around very hot fires and materials, suffer higher rates of cataracts as a result. Someone suggested not staring into the fire, and that's good advice. Shade 3 welding lenses provide good (complete?) protection, but they'll make it hard to see what's going on in the forge -- and the rest of the shop -- and especially to judge colors.

Didymium got to be all the rage a while back, but I'm not sure how. It bugs me that some places still sell didymium glasses specifically for forge welding. They DO NOT filter IR, which is the type of damaging light that a forge is going to produce, AT ALL, unless they've had IR protection added separately. At least that's what these guys say: http://www.sundanceglass.com/didymiumsr.htm

Ah, Phil beat me to it!

That can work, but you don't want your tuyere just floating out there in the middle of the tub. Add clay up to its level, and then build a firepot with it, like in this Lively style forge: This is a good design for blades, but it's not as flexible as a more traditional firepot and tuyere. As for the air compressor, it depends on how much air your compressor can provide. Might work, but I suspect it'll add a lot of unnecessary wear and tear on your machine. There are better tools for the job.

Again, though, how do you plan to weld on the plate if you go ahead with your plan? Just running a groove weld around the edge isn't likely to give you satisfactory results, and refacing a cast iron anvil by forge welding seems extremely risky, if it's feasible at all. I'd be very worried about melting the body of the anvil.

Crushed glass is often used as a cover for molten metal charges. It melts and forms a protective, impermeable layer between the metal and the atmosphere. A good campfire will turn soda-lime glass into soft taffy. Borosilicate (old Pyrex) will last a bit longer, but it'll still be at least extremely soft (or worse, I've never played with it at those temperatures) well below the melting point of copper. And neither one of them is good for the amount of thermal shock you're looking at. Definitely try the graphite. You can find good deals on scraps on eBay. It will eventually burn away in the forge, but it should last a good number of uses. Tutorial here. The part about turning out the ingot before it cools completely (but after it's solid) is probably pretty important for mold longevity.

Tim, did you get the PM I sent you?

How were you planning on welding on the plate?

If you're happy with the wood pellets that's fine, but if you're interested in coal I still think you should talk to the Cal Blacksmith guys. I know organizations around here that buy coal by the ton and sell it at a fraction of $34 per bag. I would not be at all surprised to learn that someone out there is doing the same thing, but it's not necessarily something you'll find advertised anywhere. It's about asking the right people.

Great suggestion. Back issues (with cover photos) here: http://www.ijpc.com/Backissues/ I had no idea mortars and pestles could be so interesting.

Just spitballin', but you might be able to incorporate it into cable "damascus" or some other type of pattern weld.

Thanks, Brian. That's very educational. I know you're right about the cold shuts, because I've slit a couple hammer heads and that happened to both of them. I didn't understand why until I read your explanation.

Thanks, Brian. That's very educational.

He slit that, then worked it around a mandrel of some sort, maybe the horn of the anvil. Slitting leaves more material to work with. (I call it slitting; some say splitting.)

I almost mentioned deoxidizing with a modern (zinc) penny or two, but I figured somebody would draw and quarter me.

Frosty, I think he's looking at Brian Brazeal's slitter geometry thread. Brian's slitters are sort of pointy slot punches. That's where he's getting that idea.

Sparks are one of the hazards of charcoal. You can learn to minimize them, but the occasional flea bite is inevitable. If it's not the sparks it's hot scale, or molten flux from forge welding. (These are especially problems if you let your tong hand get lower than the face of the anvil while you work.) Coal generally doesn't spark at all, but it does produce some pretty noxious smoke -- and it looks like you might have neighbors nearby. As far as finding coal at more reasonable prices, have you talked to the folks at the California Blacksmith Association? http://www.calsmith.org/ They may have ideas, and I notice that they run classes in Sacramento.

That will not work, at least not safely. Household ceramics are not made to hold up to the temperatures and thermal shock that a crucible experiences, or to retain strength at extreme temperatures. (They may be fired at those temperatures, but they are ramped up and down very slowly -- many times slower than what a crucible experiences -- and they are not asked to do work at firing temperatures.) And molten metal is much more dangerous than solid metal at just about any temperature. If these are copper cables, the melting point is near 2000 F -- and you need to superheat by a few hundred degrees for casting. For these sorts of temperatures you really need a crucible made of some sort of refractory material. For lower melting metals you can get by with a welded steel crucible if you don't mind contaminating the melt, but that's not a good idea for something that melts as high as copper. Are you trying to cast something to near final shape, or do you just want to melt the stuff into ingot form, then work the solid ingot to shape? If all you want to do is melt it into an ingot, you can get some scrap graphite (e.g., from eBay), route/carve/mill a cavity in it, and melt your copper directly in that cavity. In that case the graphite serves as both crucible and mold. I know a guy who makes shibuichi ingots this way. Put some charcoal on top of the wire to help prevent the metal from absorbing contaminants from the forge atmosphere. Be aware that fine wire has a high ratio of surface area to mass. That's always a good recipe for losing a lot of metal in the dross. The thicker the wire, the better off you are. And if you can get a pool of molten metal, then submerge your wire in that pool while it melts, you'll waste much less. Anything that you add to a melt must be preheated above the boiling point of water before it touches molten metal. If there's any water trapped inside when it's submerged, you may have a very bad day. This goes for your tongs and other tools, too. If you're hoping to cast to shape, I should mention that pure copper has a reputation for casting poorly.

Here are a couple resources you can mine for ideas: http://www.anvilfire.com/iForge/ http://www.abana.org/resources/education/chf.shtml

Tuyeres are forced-air-cooled, and most of this one is far from being in contact with the fire. Formation of zinc oxide smoke (the stuff that causes metal fume fever) requires heating zinc to near or above its boiling point, which is around 1650 F. I have trouble imagining the tuyere getting that hot. Even the flange is exposed to open air and benefits some from forced air cooling. If one were really worried about it (I wouldn't be), an overnight soak in vinegar would strip the zinc from the flange. I have inadvertently burned zinc. It's quite obvious when it happens -- bright bluish flame, thick white smoke. If it somehow happens, don't stand there and breathe the smoke. Shut off the heat and move upwind. It's that simple. We're not working in brass foundries, or welding galvy all day. (Well, perhaps some of us are. In that case, wear a respirator and/or take other appropriate precautions.)

Bentonite kitty litter is a good, cheap source of clay -- and you don't have to worry about screening out the rocks and so on. It also will crack, although using a bare minimum of water and lots of inert filler (clean sand) helps a great deal.

Regular concrete does not stand up to forge temperatures, and as ONR said it can spall dangerously at high heat. (The chemically bound water gets liberated and turns to steam inside the concrete.) Bad idea. If Phil says the claying recipe works, I believe him. But don't use regular concrete.

Then I'd file or, as someone suggested, chisel it, then finish with a file. A square broach would also be a good solution, but if you had that capabililty you probably wouldn't be asking the question. And setting up for broaching a hole that size isn't something you'd do for a one-off. ($$$)