Floor : Hull : Liner Structural Build ?

[FLexpat]

I have not had the liner out of my '76 23 Sceptre but I have cut the decks out. The PP was between 1/4 and 1" thick on the stringer tops - still surprisingly well bonded to the fiberglass lower skin of the deck. It appears that there is also PP between the liner and hull where they are screwed together under the rubrail. I was able to get a chisel under the putty and break larger chunks off of the stringer tops (got most of it) and ground on the rest to remove. I probably could have left the lower deck skin in and just replace the core and top but decided to do the whole tamale.