Posted by Adam Vincens (12.16.236.106) on July 01, 2008 at 15:02:20:
Hello, and thank you for a great resource. I have been trying to solve an issue with a silicone adhesive adhering to an anodized part. The adhesive is applied and the part is cured, and the part performs well (good adhesion and is air tight) until the part is exposed to water. After a few minutes submerged or under constant stream, the adhesive fails at the surface (adhesive failure) and water intrudes the part and the bonded pieces (both anodized aluminum) are easily separated.
I know that water wets the surface of the anodized part, and I have also found that cleaning the part with acetone prior to applying the adhesive improves the performance.
Could this be due to the sealing part of the anodizing process? What is typically used to seal the anodizing? Does acetone modify the surface of the anodized part? Should an anodized surface be hydrophobic for good adhesion to silicone?
Your help is greatly appreciated.