Right caulking for bedding my sheet tracks to teak caprails

[rkarakai21]

Any wooden boat shipwrights or marine service techs lurking with lots of experience bedding hardware onto teak?

Im re-bedding my aluminum sheet tracks, they are screwed down and through bolted through a 2 inch thick teak caprail and the bolts run right through the fiberglass and wood bulwarks to the inside of the boat.

My question is regarding what sealant should be used between an aluminum track and an oily hardwood such as teak. I have had opinions flung around suggesting it doesn’t matter, just use sikaflex or equivalent, as well as people saying to use a polysulfide such as lifecaulk. So I found most the stores have the mahogany life caulk but it recommends you prime the wood with lifecaulk primer first, of course none of the chandleries have this primer, just the sealant.

In my personal experience bonding woods like ipe and lignum vitae I’ve found with a good dose of acetone before glueing or epoxy just about anything can be made to stick.

That being said, these are long sheet tracks with tons of fasteners and I’d rather do it right and not have to rip it all up in 2 or 3 years.

Have at me with your opinions.

Can you use lifecaulk without the primer?

Thanks

Ryan

[LakeSuperior]

You are essentially using the caulk as a gasket. Think the track compressing the caulk. Therefore, IMHO the primer is not necessary. It is different when you are trying to bond the caulking to the wood like the sides of teak deck seams.

I am more of a fan of the Sikaflex brand than polysulfide based products. That is because ultimately, the urethane based products are far superior.

[rkarakai21]

Thank you.

[Bowdrie]

Yes, what LS said about 'gasket/compression/primer' is true.
A trick with the gooey stuff is to not tighten the fasteners all the way up tight at first.
Let the stuff cure, then give the screws/bolts the final turn, (or 1/2 a turn,) that way you're not squeezing out what you want in there.
Take it easy on the torque when fastening anything to wood/fiberglass, you have to have room for the sealing product.