Hello, I just got an old 85 Viking Mini Gasser and the top vent had leaked a bit so the previous owner ripped the inside roof out to fix but never finished. What do I use for insulation between roof and the luan panel? Any help on this would be great. This is my first fix up project ever and I could use the help. Thank you!

 

Normally they are laminated (glued) together with proper thickness foam insulation. Double check Lepage's PL-300 adhesive, I believe it's the right number for gluing foam insulation. Clean both surfaces well for better adhesion and more strength.