bedding compound behind rub rails and changing bolts

[mic]

I'm about to pull the rub rails off my boat, sand them back and give them a couple of coats of redlead then put them back on. What is a good bedding compound to put between the rails and the hull? At present i think it has tar not sure if it is petrolium based or ashphelt based. Also my hull is copper fastened but the rub rails have iron galvanised bolts, should i replace the bolts with copper, bronze or should i go 316 stainless or monel.

[Scott Rosen]

Rubrails can be a problem spot for rot if water gets between the rail and the hull. It's not easy to get a perfect fit. I would seal the inside face of the rail with CPES. I would bed the rail with generous amounts of a sealant goo like one of the Sikaflex products made for the purpose. The goal is to prevent any water from getting in between the railand the hull. Don't use a stong adhesive like 3M 5200.

If you haven't had any problems with the galvanized bolts, then there's no need to change. If you've had rust bleeding or if there is evidence of corrosion, then you should go with bronze. Don't use stainless, because you may get crevice corrosion and the resulting rust stains.

[mic]

Thanks for the reply Scott, but i'm not sure what CPES is and which Sikaflex product in paticular are you refering to.

[Walcheren]

When I was in Port Townsend a few months ago visiting the Wooden Boat School I saw them use "boat felt", a tar impregnated material. This went between a wooden hull and a rub strake. Looked like a piece a cake to do. They had it in 2 or 3 foot wide rolls and just cut the right piece of. I tried to get it here in B.C. but was told it is available on the East Coast at $200 a roll. Forget that. A similar material is used in Motor Homes, comes in narrow 1" rolls. And then there is the stuff used when installing windows in metal frames. I saw that in a shipyard here where they build aluminum boats. But after all that I will use Sikaflex LOT. as suggested in these postings.

[Scott Rosen]

Sikaflex 291 is the stuff.

CPES is Clear Penetrating Expoxy Sealer. Do a search with the search thingy in upper right hand corner of the page, and you'll see plenty on CPES.

[Thaddeus J. Van Gilder]

Dolphinite is the stuff to use.

It is far and away the best, the only way to make it better is to make it fungicidal like the old stuff.

I am experimenting with adding anti fungal foot powder. we shall see if that works!