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Helium Tank Aluminum Foundry Answered

I was looking through the internet, and was linked to this page. There they used a freon can for the foundry shell, but I thought those small helium tanks would work too. I kinda knew that a dremel wouldn't cut through it, but it is just what I put on there. I used Inkscape and GIMP to make it.
Also, does anyone know a good source for fire clay? I've heard that masonry supply stores are a good bet. Another thing - does anyone know a good page on a cheap, simple, charcoal foundry?

I made a .gif animation describing my ideas, below. In the animation, I meant to put the part about cutting the hole for the blower in the beginning, too (after I cut the top off).


I was on budget casting supply, and it said that it was $174 for just TWO bags of castable refractory! Is this normal? Where did you find $25 castable refractory, and how much was it?

Budget Casting Supply is for small orders, not cheap orders : P This is one of the times where the phone book works best-anything mailed is going to cost a fortune. Minnesota Clay (pottery supples), 55 pounds castable refractory $33 (KAS4-55)

No kidding... ...$173 for two 55lb bags of castble refractory..... .....is alot. I've never even had that much free money to use.

Instead of castable, you could rig up a foundry out of clay or fire brick. Not as portable, but cheaper, especially if you can find an incinerator being re-lined or taken down for free brick.

Isn't fire brick expensive? On Ebay I saw 3 bricks for $22. I don't even know where i'd find an incenerator.

Soft firebrick is expensive ($5-7 each new at Minnesota Clay) but the hard shouldn't be (I got a bunch off e-bay for a dollar each). To find an incinerator, look for a building with a tall smokestack : ) If you want, you can go a different rout-go to the hardware store and get a tub of furnace cement and some perlite or vermiculite. The furnace cement will be a thick paste, add some water to it for something more like pancake batter (it doesn't take a lot), then mix in the perlite or vermiculite until it's nice and thick but doesn't quite fall apart. Now you have castable refractory : ) If you are careful, and the paste is fairly thick, you don't need the inside form, just paste it inside your can. Not sure how much you would need for a freon can, but about 1/3 of a pint tub made an 1 1/2 inch think layer inside a coffee can. You can protect the soft perlite or vermiculite with an extra layer (1/8 to 1/4 inch) of just furnace cement watered down and painted on. Perlite melts a bit above aluminum temps, so if you plan on moving up to copper alloys, you might want to use vermiculite. But, perlite comes in small bags (about 1 cu. foot) where vermiculite comes in big bags (8 cu. ft) around here.

I live in south Florida, and noone has fireplaces or furnaces around here, so I don't think and hardware stores will have refractory cement. I probably just make my own.[]

there's a few instructables on metal casting and melting, one using a pizza can and some charcoal

Pottery/ceramic supply will have fire clay(~$11-$17 for a 50 pound bag). It may be cheaper/better off just buying castable refractory (~$25).

cheapest and probably simplest. Backyard metalcasting and ABCmetalcasting have lots of info.

As long as you are cutting cylinders, the bottom of a medical oxygen tank works as a crucible : )