In your reply to this topic, you mention using a rotary tumbler
with mixed steel shot for up to 2 hours. How to avoid the black
rubber tumbler barrel interior from discoloring the metal?
Ah, this is always a tuff one. First let me say people do so many
different things with their tumblers and there are so many different
tumblers with different barrel types I don’t know if I can answer
all the issues, but I can address the most common pitfalls. 09 1st,
keep your steel shot and barrel clean! Dump that water after EVERY
use, then rinse the barrel and steel shot. Your equipment is an
investment so take the time to maintain and clean it.
2nd, use a burnishing compound, burnishing compounds are engineered
for this application, soap is not. Don’t over mix or add more
burnishing compound than is recommended.
3rd, and this is probably the biggest error people make with a
rotary tumbler and steel media. Do not burnish more than 6 hours.
You can only work harden the surface of metal so much, after that
you’re doing more harm than good. Compounds break down and become
ineffective, your work starts to flake microscopically and those
flakes immediately oxidize and then imbed themselves to the barrel,
steel media and your work, making quite a black or gray mess of your
work. This also happens when the solution is not changed out and the
barrel/media is not regularly cleaned.
4th, take the time to educate yourself on the mass finishing
process, Judy Hoch has a wonderful book, and we carry a great video
as well. Remember it’s fun to play with all that cool equipment.
Hope this helps.
Rio Grande Technical Sales and Support
Please feel free to contact our Technical Sales and Support team anytime