For the vacuum infusion I need a airtight foam hull, so screwing down from inside through the foam is not recommendable. The strips are mounted "dry" and the join between is filled with an epoxy bog afterwards. So this is the place to screw down temporary small Formica strips to hold the foam against the battens. Then the self tapping screws are fitted from the back and these are holding the foam down till the inner laminate is ready.
