thru hull fittings bronze or plastic

[diverdad69]

currently my girl has plastic thru hulls and I want to replace them all, any thoughts? I also need to replace the valves mine were the old blockish gate valves, plastic too. they looked like they still worked but again, while shes out on the hard things are changing

[sailingdog]

DiverDad—

Are they plastic (which is bad) or Marelon (which is good)? Marelon is perfectly good for underwater use and doesn't have the issues with galvanic/electrolytic corrosion that Bronze does. Many higher end boats are being fitted with Marelon for this reason.

I also doubt the valves are gate valves. AFAIK, there was never any manufacturer of a plastic or marelon gate valve. All the "plastic" valves I've ever seen were ball valves.

Don't use plastic for through hulls unless it is way above the water line. Marelon is not just plastic—it is glass reinforced composite... and is far stronger and more durable than the nylon or PVC plastic fittings.

It would help if you said what kind of boat you had, and how many through-hulls/seacocks you were looking to replace. Maine Sail has an excellent post on installing through-hulls properly on his projects page.

[diverdad69]

saildog, i have 5 thru hulls, 1 at 1 1/4, 2 at 1 inch and 2 ant 1/2 inch. also my craft is an 76 irwin. the valves are brown and square, and gate valves made by a company called brakham i'll look into the marleon ones and see how they price out compared to bronze.... thanks for the link too

Sean

[sailingdog]

Glad to help. I'm guessing that Brakham is long out of business. Forespar makes some very nice integrated through-hull seacock setups out of Marelon.