I line a bucket with a plastic wastepaper basket bag and then fill
it with water. After quenching, I let it settle, pour the water off
and toss the investment, bag and all. A few years back I started
breaking out the castings dry. I let it cool for a while and take it
outside with a metal bucket, a dust mask and a leather mallet. Smack
the flask smartly and repeatedly on the side (not the ends or the
button) while turning it. The investment will break up and fall out.
I would have to recommend that it is best to do this outside only. It
creates a lot more dust than quenching and can linger inside,
probably forever, like the glass from the light bulb that blew out in
your grandmother’s bathroom in 1967.
The investment residue from whichever method you choose can go in
the regular trash. It is non-toxic and presents no hazard other than
from breathing the dust. Seal the bag so the trash guys don’t have to
breathe it either.
I find it best to let investment spills harden untouched and to break
the hardened chunks loose from the counter top or floor rather than
to try to wipe up spills. Dry investment is just easier to handle
Please use a dust mask whenever you’re working with investment or
anything else that produces dust. And the best of luck with that new
casting venture, William!