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For fluorosilicone rubber molding on aluminum, must it be done immediately after anodizing?

We are having a bonding issue with fluorosilicone rubber on metal. The question is if we use a dichromate seal on our part do we have to have the part molded within 8 hours ?

We have a customer that is trying to tell us that we have to mold the fluorosilicone within 8 hours of dichromate seal.

I believe the answer is false.

I need third party verification.

In my opinion if you have a good anodize and a good mold it does not matter if it is 8 hours, 8 days or 8 weeks.

Tom Zeitinger
Buyer - St. Lous Missouri.
December 14, 2009

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Immediately after anodising, the surface has an open pore structure.
The pores will close slowly under normal atmospheric conditions or rapidly when any of the alternative sealing processes is used.
For optimum adhesion, it is common practice to specify that the final rinse is at a relatively low temperature, no sealing is applied and bonding (paint, adhesive etc) is applied within a specified time limit; 8 hrs is common.
Once the surface is sealed, it unlikely that any further delay will significantly affect the bond strength.

Geoff Smith
Hampshire, England
December 17, 2009