Back in the early 80's I had the pleasure of working with some folks who worked on the Windecker Eagle , the first FAA certified all composite aircraft . They used the following technique for bonding fiberglass to aluminum :

First , clean the aluminum with a solution of 50/50 MEK and the epoxy with which you are going to use in your laminate .

Second, wet sand the aluminum surface to be bonded using the same solution and 80# wet -dry paper .

Third , wash the residue off with clean MEK epoxy solution.

Fourth , wash MEK off with pure epoxy .

Finally , proceed with lay up as needed.

 A few notes : Use properly activated resin for all phases , never allow surfaces to dry (be exposed to air ) , when the wet solution " sheets out " and does not bead up you have a clean surface ,we have tried this with several resin systems and it works quite well.

Rob Lueck

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