I need to reseal my portholes on my 1984 Catalina 30. The aluminum on the cabin side of a couple of the portholes also appears to be blistered as well and that seems to be where the leaks are coming from. Do I need to replace the interior part of the porthole with a new frame or is there some kind of epoxy or bonding agent that I can use to repair the aluminum. What kind of material should I use for a gasket? Is there a gasket that is made specifically for this porthole based on year and boat manufacturer? For instance through Catalina Direct or do I hand cut it to fit? Is there a sealant that is used instead? Thanks for any help or directions to various links that might be able to instruct me.
Second the recommendation to use butyl tape. It's a bit more work but does the job and, if done right, you'll never have to do it again.
One caution, if any kind of silicone was used on the ports you will have to do some serious cleaning and sand done to clean glass since the fiberglass absorbs the silicone oil from the old caulk and nothing will stick to it.
The water is always bluer on the other side of the ocean.