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Solution Being Trapped in Anodizing Racks

We are having a problem with solution being trapped in our racks. When the racks get get dipped into the hot Deionized Seal, the solution comes out and contaminates the tank. I am hoping that someone out there has come across this and can give me some advice as to how to prevent this. It looks like the solution is either Chromic or Alodine 1200S.

It is also coming out in my Dilute Chrome Seal, which is also a heated tank.

Randy A. Mattson
- Seattle, Washington, U.S.A.
2001

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The obvious answer is that you have some nooks or crannies trapping solution which the rinse tanks are not washing out. What you have not mentioned is how the intervening rinses are configured. You might want to consider some sort of agitation (air or mechanical) in the rinses or install some spray rinses.

James Totter, CEF
- Tallahassee, Florida
2001

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The rinses that we use are air agitated. Maybe the parts are not being rinsed properly? Is there a way that the solution can be "trapped" in the racks? Maybe the hot water brings it out. My thinking is that if the solution can go in the openings, it can come out with proper rinsing.

Randy Mattson
- Seattle, Washington, U.S.A.
2001

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Hi Randy.

Many people believe in a dip in dilute nitric acid will flush out the more troublesome acids.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
January 23, 2013