sand casting

Green Sand Casting in the Home Shop
Introduction
Do you remember how much fun it was to play in the sandbox when you were a kid? It was so
much fun to take a shovel and a bucket and build castles and fortresses. Now all you can do is
watch the children playing in the sandbox, unless you don’t care what the neighbors think.
There is a hobby that will give you the opportunity to play in the sand again: green sand casting
in the home shop. Casting aluminum at home may seem like an odd hobby, but it can be a safe
way to make the metal objects that you need or want.
The process is fairly straightforward: you make a pattern of what you want to cast, then use the
pattern to make a sand mold, and then pour molten metal into the mold. After the metal freezes
you end up with the piece that you want. Usually. Some of the time it takes a couple tries to
find the technique that works best for a particular piece.
My journey into metal casting started because I wanted a metal lathe but couldn’t afford one. A
man named Dave Gingery wrote a series of books in the 1980s showing how to cast aluminum
and zinc, and to use the castings to build a metal lathe, metal shaper, horizontal mill, drill press,
and several accessories (See Sources). After finishing the series I continued to find items that I
could cast, such as decorative items, drawer pulls, and sundials.
One of the most difficult things about operating a foundry at home is obtaining the proper
materials. If you happen to have a foundry supply company locally, chances are they really
don’t want to deal with a hobbyist (trust me on that one). They don’t seem to like dealing in
small quantities or they have reservations about their legal liability if you hurt yourself. And the
shipping costs associated with buying items such as sand from distant vendors can be
prohibitive.
That’s why Dave Gingery offered alternatives to actual foundry supplies. Coarser sand can be
used, and fire clay and water can be used to make green sand instead of using oil based binders.
Baby powder or foot powder can be used instead of parting dust. There are a lot of alternatives
available. The downside to alternatives is that sometimes the quality of your casting could
suffer. But this can often be solved with a little time and a file.