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Anybody have any thoughts on the best marine caulk to use on exterior boat seams.
I have a 25yr. old fiberglass lobster boat that has seams that need to be recaulked
around the pilothouse. My concern is future removal and non-yellowing. I'm
thinking a Boatlife product but notsure which one. Thanks
The 3M 4000 UV is a great product, but it does yellow. I used it on all my hatches not too long ago. It provides great flexibility and movement with the boat, but if water sits in an area on a joint, it will yellow.
3M 5200 will be too permanent, IMO. I used it when I put my T-Top back on and have noticed that it yellows as well.
I recently used Boatlife Life-Seal on my exterior seams. They also have Life-Caulk. I use the 3M products, 4000 or 5000 series, when I need an adhesive to bond two materials together. But I think you are just looking to seal a seam. I would not use an adhesive for that.
Boatlife- Life Seal is all I use for non adhesive applications. Both above and below the water line. Every time I pot a hole in my boat it gets Life Seal no matter where it is.
" I put that $h_t on everything"
Silicon will seep into your gel coat and make any future painting virtually impossible. Silicon has no business EVER being applied to exterior gelcoat and fiberglass. And yes there is "Marine" silicone sealant; use it inside or for things like sealing polycarbonate windows to aluminum frames.
BTW, you can paint over 5200/4200 etc, otherwise they will yellow.
The problem with silicone is that nothing will ever stick to that area again. You will never see a tube of silicone anywhere near a body shop for that very reason.
I actually think doing the seams in black might look nice if they were all sone that way from the beginning. My boat is black and white so it might look nice.
This has created several questions...do you use silicone, marine silicone or something else. The biggest question is my boat is new and needs fixed. There are several gaps under my bumper rail all the way around. How do I know what the factory used before I start applying something else? It looks like a silicone of some kind.