[Magesblood]

Went to a rock & mineral show today. Those shows, like air shows are very cool to me.

Anyway, there was a vendor with cast brass and copper shapes. Kinda got me thinking that I might try my hand at casting something.

I found plans on-line of how to make your own smelting furnace. Cool, very cool.

I've been looking on-line for ingots and other stuff to melt down so I can cast stuff but a lot if not all of the sites say, "contact for quote".

Is it that the cost of these metals vary that much from day to day that they can't put the price they want on their page?

Anyone have any tips on making molds of basic geometric shapes to get me started so I can go on to more complex stuff? I'd really love to do a pyramid and a sphere.

 

[aric]

metal prices really fluctuate.

I'd start out with plumbing scrap for brass/copper.
Aluminum is expensive but auto scrapyards are full of cheap aluminum parts. valve covers/engine brackets/pistons/trim parts
Iron is everywhere.

The easiest ingot mold is to find a hollow brick, some have a 1/2"x 3-4" hollow in the back

small cast iron pans make great molds for low temp metals

you can always make a mold out of furnace cement, using just about anything to make the cavity.
here is a metal pyramid candle mold.

set it in furnace cement, pull it out and you have a perfect pyramid mold

 

[Denn]

I can recommend a book- Build Your Own Metal Working Shop form Scrap - The Charcoal Foundry by David J. Gingery. This is a great little book that takes you through the basics of building a small furnace that uses barbecue charcoal to melt aluminum, making "green" sand to make your molds, and how to make patterns. This is just the first in a series of books. Subsequent books describe how to build a whole line of small machine tools (lathe, milling machine, shaper, drill press) out of the castings you make with the foundry.
Aluminum melts at a relatively low 1,200 to 1,400 degrees F and melts easily with this method. You can buy casting aluminum ingots from onliine scources, but scrap metal is easy to find and seems to work well. If I remember correctly, brass melts about 500 degrees higher and cast iron melts at 2,400 degrees. This is really hot and takes a furnace burning natural gas, propane , or waste oil. It's also alot scarier handling a pot of molten metal this intensely hot.
About fifteen years ago, I built the furnace and made a lathe and milling machine that I still use. It was alot of work, but it's really fun and satisfying to pull a casting you've designed out of a sand mold.
-Dennis