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Can sealant surfactants be removed?June 4, 2021
Q. We have some clear and black anodized (Type II) parts that get assembled with glass components using UV curing adhesive and we have a high failure rate. Temperature cycling is what initiates the failure so adhesives with more flexibility when cured are being tested, but my research indicates that the surfactants used with Nickel Acetate seal can interfere with the bond so I wish to test that variable as well. So the question is, can the residual surfactants be removed in a cost effective manner without otherwise affecting the parts?Chris Maugham
- Delray Beach, Florida
June 5, 2021
A. The seal is hydrated aluminum oxide. The coating is aluminum oxide. Anything that will remove the seal will also attack the coating. So, no, you are stuck with this batch of parts. On the next run use generic homemade reagent grade nickel acetate. Most all proprietary seals do have surfactants for very good reason, however not for you. Also, follow the anodizing with a rinse, then 5% nitric acid to flush the aluminum sulfate out of the pores, then another rinse, then dye and/or seal.
Robert H Probert Technical Services
Garner, North Carolina