I took out my R33 windows which leaked badly, dismantled them, put some weatherstripping from Lowe's in the grove where the glass (1972 boat) fits into the aluminum channel, then rebeded them back on the boat. The butyl tape (roofing) I put on the outside between the flange and cabin sides when rebeding them is 100%, but the Lowe's weatherstripping in the channel groove lets in just a few drops of water. I will take them all out again this spring and try another material in the channels the glass fits into.
I also am thinking of abandoning the stock windows, glassing over the holes completely and installing ports which open, and are smaller, safer in heavy seas. A lot more work and expense.
The main factor here is strength. I just don't know how strong the stock glass (safety glass with a laminate in it like a car safety glass) really is. Any ideas on this?? Thanks!