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I Forge Iron

Hello from GA


Slysmith

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I'm a 42 year high school science teacher.

I'm buddies with the art teacher in our school, so I can likely get him to craft crucibles for us since he is also interested in casting in metal. I have a aluminum furnace I am crafting for now and eventually I want to get fireclay and craft something that can melt copper / bronze with no problem. In time I will probably try to create something like Lindsey's furnace that lifts from above and can melt iron / steel.

I am curious about several items and I have not searched the forums yet. My curiosity includes:
--What is the melting point of firebrick? fireclay? silica sand (or slumping point)? All this verses the metals one might be melting. Would hate to have a slumping furnace.
--What compound HAS the highest melting point?
--For those that use propane furnaces, do you find the propane to be expensive in the quantities you use it? My ultimate question here is IS A WASTE OIL furnace actually worth it in effort? Most waste oil gets recycled now in my area, so I don't know how I might easily obtain it.
--Is a Coupela (sp?) actually worth it? Can you get clean metals, or does it just keep mixing in the old metals from before?
--Lost wax or greensand?
--And where the devil do you folks get nice clean ores at a decent price? I can try to recycle scrap sure... but unless it is iron, most metals I'd like to have are hard to find (Al and Cu).

Anyway, I look forward to being a part of your community and learning from the pros since I am way down the row in experience.... as in I have no personal experience.

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Welcome aboard Slysmith, glad to have ya.

Wow, lots of metal casting questions for a bunch of blacksmiths.

I've made refractory mixes before and for the time and money I prefer to buy commercial castable or rammable refractories. If you can't find one locally in the phone book or online, check with a company that rebuilds, services and installs commercial boilers they should be able to tell you where to get it.

For some of the particulars of what you'd like to do you might try one of the metal caster's fora, this is one of the more popular ones. backyard metalcasting

Cupolas work great if you're planning on pouring a LOT of iron. Copper is one of the trickier metals to cast and melts at near iron temperatures.

Al is actually pretty easy to find if you go to a small engine repair shop. Lots, most modern gas engines are pretty cheaply built and have short life spans. The scrap metal in a lawn mower isn't worth the labor to separate them so most shops have big piles out back and make periodic runs to the recycler's shredder pile which is really low paying. Anyway most shops I know of are willing to give me as many as I want to pack off. I just don't want any. ;)

When you make your metal furnace use Sonotubes, the cylincrical concrete forms. Once the refractory sets you can peel it off inside and out so it won't be damaged as it dries.

Frosty

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SlySmith, My best friend is a tech ed teacher and has gone through many casting techniques. I have seen it done on the large scale and have done a good deal of lost wax on a broken arm centrifuge, gold and other alloys. But my friend could get you the info for your sand form on investment techniques. I will ask him if he has a source of all of the info together in one place. I know he has built all the way up to his own vice out of pieces he has cast. Let me know if that would be a help. I am interested in some of the same things too. I want to make a bloom furnace and use local ore to create a bloom for an iron source in a knife project(one of these days)

Devin

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Bloom furnace... Like to hear what a bloom furnace is.

Yes, I'd love to hear what you friend has to say about all his techniques. What works, what doesn't. I'm not poor, but I can't really afford to create expensive fancy furnaces etc. Besides the making my own stuff out of "trash" is kind of fun too.

so Sonotubes? Are those the yellow cardboard things I see at home depot for casting concrete INSIDE them. Never thought about using them the other way around. VERY smart.

So can someone tell me really what a cupola is? Is it a furnace that HOLDS your iron inside and then you somehow TILT it to pour out the molten metal? When casting iron, how much of dealing with slag do you need to do? Wouldn't Iron oxide be a real problem unless you used something like the Bessimer process? I'm a long way from casting iron, but I'd love to hear about the process and what I want to work toward.

I currently have a post at:

http://www.iforgeiron.com/forum/f86/first-forge-seeking-criticism-12053/

If anyone wants to weigh in.
Thanks.

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This site is by a fellow who has been making cupola furnaces for a number years, I recommend buying his book(s) and DVD(s).

Home Iron Foundry, Small Cupolas

Below are a couple pics of the cupola at a local iron pour last June. I don't have a shot of them tapping it but NO you don't tip them over and pour. You tap a hole at a level in the lower chamber, when the ladle is full or the chamber is empty you plug the tap with mud. Special mud, usually Bentonite and silica sand.

I believe you should keep casting something like iron as a long distance goal, it takes a lot of expertise and knowledge to do it safely and safe is a relative term when you're dealing with molten metal. 10lbs of molten iron has roughly the explosive equivalent of a case of dynamite ad it most certainly CAN explode if you make a mistake. Just a few drops of water in the wrong place and things can get deadly quicker than you can blink.

Asking questions is a wise decision, have you joined the metal caster site I recommended? One like it? Have you contacted a local casting club? A local artist caster? Believe me a couple hours of hands on is worth days and weeks of research.

Frosty

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  • 2 weeks later...

What part of Georgia are you in? I'm in Atlanta and would be glad to show you my casting techniques. I don't do a lot but can certainly explain the process. What has worked for me and what I would do different. I have a gas burner and use wood and have been known to make charcoal.(Which usually gets used in the smoker or BBQ)

You have asked a lot of questions. Ore is for smelting as is the bloomery furnace. Not really what you are looking for I think. Smelting is reducing the "rock" to metal. Far too many sources for materials to waste time smelting.

Aluminum cans make great material contrary to what some people say. They have drawbacks, but are readily available.

Like Frosty said check out the back yard site for more specific info.

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