Hi Wil
I haven't been on the forum for a while, so I missed your question.
I first coated the entire 4 mm plywood sheets with thin glass and epoxy. Then I cut the sheet into pieces.
In the photos of my build you can see that I use a temporary wooden strip between the chine batten.
This used to clamp the two layers of plywood together with screws during the drying of the epoxy.
I used stainless staples for attaching to the chine batten.
Is this an answer to your question?
Greetings Jan