I would not use glass, I would use epoxy. Lighter, stronger, and you get both a physical bond, and a secondary bond. If your looking at buying supplies or especially competant materials tech support go to
bateau/boat builder central. They know what they are talking about and you can talk to them on the phone.
I would take a piece of wood, or even your foot, and press against the side of the stringer to see if the stringer skin has separated from the stringer foam by pushing in on it. If it is still connected, you won't get much flex in. Then I would drill small 1/8" hole down near the bottom of the stringer, especally near the stern, and see if water comes out. If it is real wet, I would plan on cutting the top of the stringer box, and digging out the wet foam, and replacing the foam. You can't believe how heavy those stringers become when they are wet. If it is dry, but loose, I would go with the epoxy every 12" the length of the stringer approach. It will reattach, and add a little strength. If it is a little wet, you will have to make the call. A wet transome and wet stringers/coring can add 400 pounds to these boats. I weighed my transom tearout, and was stunned at what it weighed, over 200 pounds.
If you have to cut the top off the stringer, and put foam in it, I would put 4 layers of 45 degree biaxel 6 oz cloth on it offset by an inch or so to seal it back up. It will be stronger than new.
In any case, I would run some of that down the sides/tabs of the stringers to reinforce the hull to stringer connection. This is a week link in these boats.
The connection/structure points of failure in old seacrafts seem to be
- rub rail joint for the cap/liner/hull
- stringers loose from the floor
- gas tank platform and bulkhead
- transom, they are all shot after 15-20 years
- sole/liner to stringer connection
- floor/deck/lid coring