We are having problems adhering silicone rubber to our aluminum substrate. There is a bond check after molding, but we find this to be ineffective, since we are finding failures at customer sites. The problem does not affect some of our HCR materials, but only injection-molded silicone parts. We have investigated our aluminum substrate cleaning process many times. Applying bonding agents also seems to be working, since we are seeing problems with bonds to the silicone rubber. Any help will be appreciated. @ Ask The Experts

Silicone Fabrication Q&A

We are having problems adhering silicone rubber to our aluminum substrate. There is a bond check after molding, but we find this to be ineffective, since we are finding failures at customer sites. The problem does not affect some of our HCR materials, but only injection-molded silicone parts. We have investigated our aluminum substrate cleaning process many times. Applying bonding agents also seems to be working, since we are seeing problems with bonds to the silicone rubber. Any help will be appreciated.

Answered September 20th, 2010 by Expert: Brian Higgins

Our experience shows Nusil MED 6-161 to be the best primer for this type application. Use of this primer and making sure you have a clean surface is the most important factors in achieving a strong bond. Also, wiping off excess dried primer residue is important.

Brian Higgins

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