Glue up EPS with epoxy

Last time I used elmers and applied to both sheets before bonding together. this time I am using a 6" fiberglass stringer between the sheets and epoxy to stick’em together. Do I need to apply epoxy to both sheets or will one side do? Thanks

Anytime you try to bond two surfaces together, you apply bonding agent to both surfaces.

Especially if the surfaces are rough, or absorb any glue.

Thanks Lee. This will be my first experience with epoxy or anything other than plain old glue. Just wanted to doublecheck. Have a little warm weather window coming, so trying to get all my mess ready.

Some knowledgable epoxy builders would say to saturate both surfaces first, then rub them together, spreading the epoxy into all the wierd spaces, filling the voids, then clamp together without pulling the two parts apart.