rebuilding seacock

[shawn382]

I am rebuilding my first seacock and I would like to coat the plywood backing plate with some kind of epoxy and there seems to be an overwhelming number of products. I would like to know from other board members what products they have used and what works well and maybe even what to avoid.

My next topic of concern is whether I should use 4200 or 5200 sealant to put everything back together (thru hull fitting, counter sunk bronze screws, epoxied wood, seacock). Metweld from System Three was something else recommended. Any input?

[Larry DeMers]

Epoxy would be a possible problem. You have to put it around, but not under the seacock, as the whole seacock is made to be seated in and to compress a very slight amount, the teak pad you are concerned with. I used a single coat of varnish on the pads, after sanding them off a bit. This works great. But using epoxy worries me a little. Epoxy is fairly brittle in it's unsupported form, and the wood does expand etc. It's hard to remove in the tight spaces, and really does nothing that a simple application of cetol gloss does not do.

Regarding using 4200 or 5200. 5200 should not be used on anything that is not to be a permanent bond. Only one place comes to mind..the hull to deck joint. Everything else must be made to be repairable. So 4200 is the strongest bond you want to use. I am using 3M 101 on my heads' seacock (repaired and lubed). Works very well.

Lastly, Good Old Boat had a summary of which products to use in most marine situations. You might check their web site for the article.

Cheers,

[marka]

You might consider making new backing plates from Vynalester FRP. (3/8" thick fiberglass-like stuff). They will last the life of the boat with no refinishing required. Check the archives for sources. I did mine a couple of years ago.