Who has had experience with this. My 1978 23's are leaking. I took out the main starbd one. Is it possible to get the plexiglass out and re-bed? It looks like you would have to disconnect the frame. What is the very sticky gray bedding compound they use to bed the frame to cabin wall? Is it best just to buy new ones? Thanks for your opinions. This is the biggest PITA of all the work I've tackled on this boat.
Port lights which are made of, lexan, Plexiglass and other plastics require a caulking that doesn't contain harmful chemicals. The gray caulking you describe is probably Butyl Tape. I like Butyl Tape for bedding hardware such as tabernacles and lifeline stanchions. I used it last year on my bow stem chainplate and mast tabernacle.
It may be good on a forward hatch I really don't know. I used Dow Corning 795 on my forward hatch frame. I'm told that boat manufacturers use DC 795 on plastics such as hatches and port lights but it has been my experience that this stuff is very messy to work with. I was told just the other day that Sikaflex 195 is very messy to work with.
I had a leak coming in from the Lexan lens on my forward hatch and I was beside myself trying to figure out what to use in adhering it back on my Gray Marine plastic forward hatch until I talked to a friend of mine who had replaced the lens he had accidently broke on his Pearson forward hatch. He told me that he used Dap Silicone Rubber Adhesive Caulking. He said to make sure I got the Silicone Rubber. He also said to clean the area good so that it can adhere. Don't use Acetone!
I went down the club on Friday and removed the hatch cover from my boat and took the lens off with two putty knives. I used a torch to heat them up. I used a wood chisel to scrape the old residue out and followed that up with my Dremel tool with a drum sander. Then I cleaned the frame and lens with denatured Alcohol. I applied clear Dap caulking and that lens seems to be adhered well. I really don't expect it to leak. My friend told me that his lens never leaked and we're talking about a lens that is not screwed to a frame. It's adhered to the plastic frame.
Years ago I had my two large cabin port lights off and I'm pretty sure that I used a similar caulking and screwed them back in place.
All I can tell you is that if I ever need to caulk any type of plastic hardware on my boat, I'm going to use Silicone Rubber Adhesive Caulking.
For certain types of metal hardware I like Butyl Tape for certain types of hardware and 3-M 4000 or 4200.
