DIY cold casting

[mobile_bob]

usually these three words aren't used together in the same topic, however
in this paper i would like to relate to others a method of casting small to medium size parts
using a cold process rather a molten metal process.

it works like this

we use the cast iron chip left over from a brake lathe, selecting the best and cleanest cast iron chip we can get
to that we mix in fiberglass polyester resin which has been activated, and poor the mix into a mold.

the mix is very stiff, being about 90% cast chip by volume, it sets up in a fairly short time and depending on the
quality of the mold gives good detail.

the resulting casting is nearly as heavy as cast iron, machines very much like cast iron, will drill and tap with threads
like cast iron and in most practical ways it is cast iron but not quite a strong as cast.

to add strength one can add chopped fiberglass, and/or build up and include a steel armature which is a tech term for
a steel skeleton which purpose is much like rebar is to concrete.
one can also cast in threaded steel or any other metal inserts, air lines, fuel lines, hyd line, electrical conduit or raceways
etc. if needed.

the end result with chopped fiberglass and a steel armature makes for a very  strong casting suitable for various purposes
the only drawback being temperature limited to about 200 degree's F, although using epoxy resin will increase the temp limit
substantially.

all manner of small housings can be made in a home shop for just about anything one can think of. don't know if i would try it
but i would not be surprised if an engine crankcase could be built with the process.

simple wood molds built up on pieces, well waxed and held together with deck screws are sufficient for most purposes.

over the last few years countless commercial outfit have sprung up and make composite cast parts for industry, from tiny to several tons
in size.

just wanted to pass along this very useful information that every DIY'er should have at hand to make parts with that are difficult to
make because of lack of machine tools or need for complicated welding of several components.

for more info, google "composite cast" or "polymer cast"

bob g