I want to squirt some expanding polyurethane foam into a section of mdf box cladding covering some copper water pipes to cut down on draughts (an insects) from getting into the kitchen. Since I want to be able to remove the cladding if necesssary, what can I use as a release agent to prevent the foam from sticking to the inside of the cladding? The stuff seems to stick quite firmly to prety much anything.
I'll remove the section of cladding before applying the foam, but then replace it before the foam has set, to get a reasonable seal between the two.