Milky film on bronze pieces after ultrasound

Cloudy/Milky film on bronze pieces after cleaning them in ultrasound

Hi, folks. I have used an ultrasound machine with a heater to try to
clean polish out of the nooks and crannies of bronze piece after I
polish them.

Unfortunately, when I remove the pieces from the ultrasound they
have a milky cloudy film finish on them. The only way to remove that
milky finish is by taking the polishing wheel to the piece again
thereby dirtying it up again. So, I’ve basically retired my
ultrasound machine except for stainless pieces, which do not get
that milky finish on them. I’ve noticed my silver pieces also tend
to get a dingy/milky finish on them when I take them out of the
ultrasound too.

Any solutions to this problem? I’d like to be able to use the
ultrasound because, theoretically, it will make my cleanup faster
and easier. But if I have to re-polish after removing from the
utlrasound it defeats the purpose.

Thank you.

The question that comes immediately to mind is: “what HAVE-YOU in
the ultrasound? What solution?”

Gary Strickland, GJG

The solution you are using is causing this… what are you using?

Russ
The Jewelry CAD Institute…

If you use cleaning supplies in the ultrasound’s water try another
and/or turn down the ultrasound waters temperature to ~80 C. But I
think the problem is with the cleaning supplies.

Cloudy/Milky film on bronze pieces after cleaning them in
ultrasound 

emulsified oil from the polishing compound, most likely. The heated
bath, water, and air emulsify the oil left from polishing. Try other
cleaners added to the bath. Never use too much cleaner in the bath,
ultrasonic works better with less. If it is a persistent problem,
presoak the pieces in Simple Green solution or similar to break down
the oil. Following ultrasonic with a steam clean is effective at
removing the emulsified film.

Dan Culver

Are you using an ammoniated solution?

The question that comes immediately to mind is: "what HAVE-YOU in
the ultrasound? What solution? 

I have used ammonia and water. And I have used a purple fluid
supposedly made especially for ultrasonic machines and cleaning
jewelry. Unfortunately, I’ve had the same result with both mixtures.

The purple is called Oakite and if you leave the pieces in there too
long it will become contaminated…try just a little bit of time or
dipping it in and out of the ultrasonic.