If you are referring to the thin bead of caulk on the top edge of the rubrail, I used 3M Marine Grade Silicone Sealant that was recommended by West Marine. Just be sure to cut as small a bead as possible to control excess caulk and subsequent cleanup
I think it has been discussed somewhere on CSR to NOT caulk the underside of the rubrail.
OK, I’ll bite on the obvious question, why shouldn’t you caulk the underside….seems like we can all get a lot of water behind the rubrail from the bottom, too!If you are referring to the thin bead of caulk on the top edge of the rubrail, I used 3M Marine Grade Silicone Sealant that was recommended by West Marine. Just be sure to cut as small a bead as possible to control excess caulk and subsequent cleanup
So it can drain. Somewhere I did a series of posts on re-sealing the deck to hull joint on my 52DB including reinstalling and caulking the rubrail. The top of the rubrail was sealed using Sikaflex 295UV and bottom left unsealed. I thought about sealing the aft parts of the rubrail underside as water is constantly splashed there underway but then where is it going to go? The folks that did mine said they never caulk the underside as completely sealing the rubrail is impossible; it needs to drain. They did a lot of prep including a primer on the surfaces before applying the caulking.
Like TT said, it's for drainage. The tiny little bead of sealant along the top is not very good and doesn't last long. This is why it's not even sealed from the factory - although it appears sometimes it is done. I see a lot of Sea Rays in my line of work, though, and much more often than not, the top is not sealed from the factory.
