After reading along for several months I finally have some
questions. First when mixing investment for casting must you use
the black rubber bowl or can you use any type bowl? My rubber
bowl is small and sometimes I want to mix more than it can hold.
Second what is the best way to finish casting? In the class I
took, after removing and grinding off the sprue, we used a series
of Cratex wheels and then polished the casting. I have read that
you can finish castings in a tumbler but am not sure of the
process or what media to use. I have stainless steel shot and
burnishing liquid. I am sure these are basic questions and thank
you all for your help.
After reading along for several months I finally have some
questions. First when mixing investment for casting must you use
the black rubber bowl or can you use any type bowl? My rubber
bowl is small and sometimes I want to mix more than it can hold.
You can mix in anything (that will fit in your vacuum bell jar).
For large pours I commonly use tupperware…
Second what is the best way to finish casting? In the class I
took, after removing and grinding off the sprue, we used a
series of Cratex wheels and then polished the casting. I have
read that you can finish castings in a tumbler but am not sure
of the process or what media to use. I have stainless steel
shot and burnishing liquid. I am sure these are basic questions
and thank you all for your help.
Tumbling is really only useful for pre-polishing. You still need
to mechanically remove the rough parts with files, sandpaper,
rubber wheels. etc… The stainless steel shot is purely for
polishing. We used to cast alot of charms and tumbling was the
only way to affordably polish them (we weren’t worried about
small parting lines), and is a several step process with steel
shot being the last step. I have been known to tumble entire
trees of castings just because it makes the tree look so much
nicer!
Jeffrey Everett, jewelry craftsman
Handmade 18K, 22K, and platinum gemstone jewelry.
Diamond setting, rubber/metal molds, casting, lapidary
Die and mold engraving, plastic patterns for casting.
Jewelry design, cad/cam, milling, scroll, filigree, & more.
P O Box 2057 Fairfield IA 52556 515-469-6250
You can use a stainless steel mixing bowl. As far as tumbling,
it is great for pieces with crevices, intricate surfaces. The
tumbler acts as a burnisher and will semi-finish the work. We let
ours runs for several hours to get maximum benefit.
Just jump in!!!.. As I was told… each to his/her own liking!
Just continue to try various wheels, speels, roughes, loughes,
etc… and keep the ones u prefer and seem to give u the best
results!.. we all have a different ‘hand on the wheel’ and now I
think thats what matters… … see something that looks
interesting … give it a try …
