"Treedweller" wrote in message
...
I'm looking to make some simple one-sided castings from tin, pewter,
zinc, or other easy metal. I've tried sand casting (distorted when I
poured in the metal) and carving a wood mold (moisture boiled out and
created air pockets).

Silicone molds may be suitable for this, although a bit much for just
one-sided castings.

Plaster, cast around a greased pattern and baked in the oven (at 500°F for
an hour or three) will hold up to all white metals. Better still, if your
mold fails, you can grind it up and viola, Plaster of Paris ready to use
again!

Wood will only work for solder (basically pewter), the cellulose and etc.
decomposes (burns) much above 400 or 500°F, releasing gas.

What was wrong with your sand casting? Sand, properly bonded and tempered,
will do anything from mercury (heh, well, if you cooled your mold with dry
ice first) to steel and beyond. If it can be melted and poured, chances are
it's been put in a sand mold of some sort at some time.

Greensand can be made very simply from sand with a little clay and water to
make it sticky, if you don't know how it should feel it will take a lot of
adjustment to get the right mixture but it's the simplest, easiest to use,
and oldest (i.e. ancient) route.

Anyone willing to save me some of my next few obvious mistakes? If I
go for soapstone, where can I get a small piece cheap? will the Satin
Cast work well (I ordered some)? Any other suggestions? I've sen
rubber mold products, but would expect it to melt when exposed to
molten metal.

Silicones are available which withstand up to 800°F, these are a bit
expensive; a cooler-rated one can be used, although you get shorter life out
of it.

Tim

--
"California is the breakfast state: fruits, nuts and flakes."
Website: http://webpages.charter.net/dawill/tmoranwms