Ultrasonic cleaning machine: ever use one on coins?

KISHU1

My mother received one of these ultrasonic cleaning machines for her jewelry and on the box it says it is safe to clean coins. Has anyone ever used one and what harm can it cause? There are no chemicals involved and it can also clean CD's.

Thanks

Frank

Coxe

Does it say it is safe for emeralds (which notoriously scratch easily)? I also have an ultrsonic cleaner and never put a single coin in it. You have to be carful with jewelry in it too. Best to suspend secured by rubberbands in a way that it never contacts the sides of the cavity and also need to make sure no stones are loose in their settings.

Jdurg

The ultrasonic cleaners work by vibrating the water and the object at such a high frequency that anything not physically bound to the main object gets shaken off and carried away by the water. This would be for things like dirt, "gunk" or any loosely bonded chemical contamination. It's not like a chemical cleaner which works by removing a layer of material from the surface of the coin. Ultrasonics will just remove dirt and crud but may also alter toning depending on the strength of the ultrasonic cleaner and the strength of the "bond" to the base metal. (When I interned at a forensics lab my senior year of college they used an ultrasonic cleaner to clean the components of the GC/MS when it was being cleaned, after the ceramic pieces were bathed in aqua regia. They used a REALLY high powered ultrasonic cleaner which I would think could do some damage to some coins).

Classof67

I purchased a commercial one a while back and experimented on some junk silver. Cleaning solution is needed, and it needs to be a heated model. I really thought it would work like putting a dirty watchband in, and instantly zap the dirt. Not so. Took several hours. The coins were in the supplied wire basket, and every placed they rested on the wire, the dirt remained. It gave a very eerie looking white finish to the cleaned parts. I wouldn't use it on anything of value, and if you just want to clean filthy junk silver, I think soap and water would work better. If anyone else has experience with this, please let me know if I am doing something wrong, but my experience was a total waste of time.

JT

shmort6552

I think Coxe hit it right on the head. You to find a way to suspend them in the solution (some kind of ring??). This would prevent them from contacting the wire/sides etc.

Bruce