I originally purchased 3M Auto Black Super Weatherstrip and Gasket Adhesive to install new gaskets in my portlights. In reading the directions just now I realize that it works like a contact cement. That is, you are supposed to coat both pieces (portlight and gasket) let dry to tacky and then install. I’m wondering how hard this is to use in practice since our portlight gaskets are round and have to be fit carefully into a channel. Seems like knowing what part of the gasket to coat with adhesive would be tricky and made more challenging by not being able to reposition the gasket.
I’ve also found online a black silicon for installing weather strips: JB Weld Black RTV 100% Silicon Sealant and Adhesive for weather stripping and other things. Would this be easier? (I also found a Permatex that said it can be repositioned.)
For those who have replaced their portlight gaskets, what adhesive did you use and how did you use it?
Jim
Last year, I replaced the gaskets in all 13 of my portholes and hatches. I used the Silaprene neoprene adhesive listed on the Atkinson Hoyle website. Atkins Hoyle’s shop is about 1/2 hour from my marina. I dry fitted, then pre cut the new gasket an inch or so greater in length than needed for each fitting, applied the adhesive sparingly in the channel as a 1/8 to 1/4” bead, then fit the gasket in the channel with the seam always on the topside of the porthole and never stretching the gasket material. As the two ends of the gasket came together, I made my final cut for a tight seam using a small wood block as a cutting surface. A bit awkward because of the need to cut upside down. I then closed and locked the porthole/ hatch while the adhesive cured. Results were good.
I simply scraped it out with a tool that more or less matched the channel. I don’t remember what tool, probably one meant for some other purpose like a thick feeler gauge with a rounded end or something like that. There wasn’t much adhesive in the channel. I’m sure my replacement was the first since 1988 when the boat was built.
Atkins and Hoyle have the material but their prices are very high. It’s common auto supply material. Nothing special at all. Comes in rubber or silicone rubber
