Brown spots after tumbling

Jewelry Discussion
1

Hello, I have consistently been having a problem post tumbling that
consists of a brown filmy type of residue that appears about 2-3 days
after my final tumbling in porcelain is complete. I originally
thought this was due to my applying silver black to the pieces prior
to going in the tumbler, but it appears only on some pieces and not
just where it has been applied. Could this be due to my water? Any
ideas or suggestions would be much appreciated. I am using a
vibratory tumbler. Thank You! Alana Berg

2 
   Hello, I have consistently been having a problem post tumbling
that consists of a brown filmy type of residue that appears about
2-3 days after my final tumbling in porcelain is complete.

Alan, In order to attempt to answer this question I must first ask a
couple. What metal are you finishing? Are you using the same media
to finish gold and silver? During your mass finishing process, do
you use carbon steel either on your parts or in the same finishing
machine? I am already assuming that you are using tap water since
you question it. Renting a DI unit from culligan is a pretty
inexpensive alternative to tap water and its issues. (not a water
softener that uses salts but a DI unit).

Best Regards,
J. Tyler Teague
JETT Research
(Jewelry Engineering, Training, & Technology)