"Spehro Pefhany" wrote in message
...

A friend is cleaning brass prior to reloading in an ultrasonic cleaner
using an old formula-

1 qt H20
1 cup vinegar
1 Tsp salt
1 Tsp soap

Seems like a couple of the pans have corroded through on different
brands of unit- destroying the ultrasonic cleaner. The brass should
not be in contact with the pan (there's a stainless basket, or plastic
in the 3rd one he's trying).

Any reason why this would happen? There's not that much difference
between (presumably 400-series) stainless and brass on the
electrochemical series.

Thanks for any leads..

--
Best regards,
Spehro Pefhany

The vinegar salt mixture is essentially poor man's hydrochloric acid.
It is chewing the heck out of the stainless.
It is probably also corroding the brass.

In any case, definitely get rid of the chlorine.
Try citric acid or sodium bisulfate.
But my real suggestion is to separate your brightening and cleaning
operations.
Use the acid to remove corrosion without the ultrasonic machine. Then clean
in the ultrasonic with a mildly basic cleaner to neutralize any acid
residue.

Paul K. Dickman