My son and I are building a 16 ft double-ender with transom from Roger Fletcher's book, and enjoying every minute.  My son planed all the scarf joints and we made the side panels, frames, stem and transom before he went back to school out west.  I've since assembled the sides and installed the frames and transom. He's coming home for a week of break and I want to get some supplies in so we can work together.  But I have a couple of questions about fiberglassing, which I've never done.

1. We didn't put fiberglass on the inside for strength, but reading through the posts, it seems that fiberglass inside is the best for impact.   Does it do any good to glass the inside of the 1/4 sapele sides between the frames? If so, what weight and weave would you use?  (My son will use the boat on the rivers of Oregon and Washington, and he's new to wood boats, but not to rowing in rivers).

2. What weight and weave of glass is "good enough" for the outside of the sides to provide abrasion resistance. And the bottom?

I've learned an awful lot from this site; it has made the process enjoyable and rewarding for a complete newcomer. I'll post some photos of the fun up to now soon.  Just about to set the chines.  Have to plane em down just a bit.

David