what do you mean by delamanation? bigfoots won't get the traditional delamanation like other trailers as that is the thin fiberglass board delamanating from the foam and frame and it looks like a giant air bubble. it is pretty much a rare thing now but still happens.
with a big foot or NL or any other pure fiberglass clam shell design you will get actualy fiberglass failure, and the proper way to fix it is to grind it out then re-filberglass to build it up again. you could just inject resin into the part that is seperated but thats just a bandaid and no guarentee that it won't keep going. with your kind of rv it is more constructed like a boat. for repairs on the shell reading up repairs on fiberglass boat hulls would be the best advice I could give you.