Hi everybody- I’ve been lurking for awhile and learning. I’ve
been doing gold and silver fabrication for many years as a hobby.
My pieces are one of a kind some with gold granulation. I
occasionally will cast some pieces, but often get fins or lines
or burs where the mold halves meet. Final finishing these by hand
can be very tedious and time consuming. I’ve tried rotary
tumblimg with steel shot, and get a good polish, but the defects
remain. Can I use other polishing media in the tumbler to remove
these annoying blemishes? Thanks to all-- Irv B.
Irv,
To remove parting lines from castings I usually use an abrasive
wheel. If you throw your castings in a tumbler to remove the lines
then they will lose that much detail all over the whole piece.
Unless your designs aren’t that detailed. I usually use a 3M
deburring wheel. They sell them in larger sizes for a buffing
machine, but I cut one up into little circles in sizes to use on a
flex shaft. Either way it is gets rid of the lines quickly and
leaves a nice, smooth surface. There are probably other abrasive
wheels out there, too, that you can use to the same effect.
What about cleaning up the waxes before you cast them? Save much
more time and also material. Janine in still raining California
I occasionally will cast some pieces, but often get fins or lines or burs where the mold halves meet.
Hi Irv,
I assume the fins or burs are present in the wax so my suggestion
would be to make the repair in the wax before casting. Since most
of our castings have a lot of detail, I repair any minor flaws
from wax injection before I casting. If major flaws, simply inject
another wax model. Try to cast waxes as near perfect as possible,
it is much easier to fix flaws in the wax than the metal. Hope this
helps.
Charlene
Charden Designs
Monterey Bay - California - USA