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Need Anodizing Defoamer

I am looking for some contact information regarding defoaming agents compatible with both organic and sulfuric acids. Thanks!

Chris Colbert
- Manteca, California
1999

Chris, normally defoamers are not required if this is Type II or Type III hardcoat. Could you give more details? Is a soak cleaner being dragged into the anodizing solution(s)?

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan
1999

Bill, the foam is thought to be arising from degraded constituents from the organic acid aided with air sparging/mixing. Carry over is most likely not the problem as all of the pretreatment chemicals are followed by 4 DI rinses. The problem is very minor on a "fresh" recently made-up bath, but begins to become a problem when the bath is approaching ~ 2/3 its useful span and gets worse as time goes on. The problem comes from the foam building up until it begins to stick to the busbar and then drips onto the parts when in the dryer.

Chris Colbert
- Manteca, California
1999

Chris, is the air supply an oilless direct drive Rotron type blower? If the air is from a compressor that uses oil it could be oil. Even if moisture trap filters are changed. Are you using an additive, is this a Type III hardcoat anodize?

bill hemp
- Grand Rapids, Michigan, USA
1999