Pretty vague thread, beyond talking about "Through The Roof" stuff - which is pretty vague in its description, at least at Through the Roof!® by Sashco - Roofing Sealant & Caulk
Is there something in there I'm missing? It's got that "Marvel Mystery Oil" style to it, light on what it is, heavy on promise.
Epoxy sounds a lot better. I know I can paint it, I know I can put it on a vertical seam if I use fast drying stuff, and I know it's going to seal a tight/small steam where two pieces of fiberglass join together. The fiberglass isn't cracked, it's just old seams that are a bit weepy at the joint.
I also have used Eternabond type tape on a few metal seams from the roof lift, and it does seem to work well. Perhaps it will work on these seams.