Metal finishing Q&As since 1989

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Haze film on Sterling Silver

 

I am being told of a cleaning problem in our washout department. Seems all the sterling silver we put through our washout line comes out with a haze on it that has to be dry wheeled off. We had the haze on the surface analyzed and were told there were residual salts from the polishing compound on the surface. I am trying to figure out what is going wrong. Our system consists of a soak tank, ultrasonic tank with Oakite [Chemetall], then first rinse and finally second rinse followed by a hot air dry. The only tank with ultrasonic action is the ultrasonic clean. Before I spend a lot of hours designing experiments to weed out all the variables, has anyone had this problem or know of something obvious that washout is doing wrong. I just found out that we are dry wheeling thousands of parts and living with this but I think that's ridiculous.

Tino Volpe
- Cumberland, Rhode Island

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I would look at high temperature and high pH first.

  
Tom Pullizzi
Falls Township, Pennsylvania