Ultrasonic Cleaners have different strengths. If you purchase a unit that is made out of plastic, the plastic itself absorbs the ultrasonic power which reduces cleaning power. The better units are made of all stainless steel including the basket that holds your part.
If removing lettering or paint off of the reels is a concern, then lower bath temperatures are recommended. The other factor in all of this is the cleaning agent you use. Some cleaning agents are a lot more aggressive then others. You should use alkaline based soaps. Try using a lower bath temperature along with a small amount of soap, maybe a 20-1 dilation ratio to start.
One more thing that will help you, Keep an eye on how long you are cleaning for. The longer you are in the bath, the more chance you have of removing something that you don't want to.
Hope that helps!
Frank
[edit]Edited due to violation of our FAQ's[/edit]
