Depends
If it's leaking under the frame, I would pull and rebed the whole thing. If it's the foam gasket that is the problem, Pompannette(the mfgr) is higher than hell. Dont know bout Thrifty which is another good source. BUT read in either Cruising World or maybe on here(go to archives) about someone using that insulation with one sticky side for windows and doors. Said it stopped the leaks. For the price diff, it's a no-brainer. GOOD LUCK