Bronze or Stainless Steel Thru-Hulls ?

[Hampus]

Replacing all the through hulls and ball valves. What should we go with, bronze or stainless? Stainless is almost 5 times as expensive as bronze...

/Hampus

[rtbates]

Use SEACOCKS, not ball valves..
Spartan Marine, Bronze and Stainless Marine Hardware, Seacocks, Portholes, Thru Hulls - Spartan Marine Hardware and Accessories, sells bronze seacocks/thru hull. Mine, on Seraph, are 26 years old and function like new. Ball valves are for HOME plumbing..

[witzgall]

Some of our bronze thru-hulls are original 1985. Do you plan on keeping the boat for over 25 years? For a fiberglass boat, bronze is up to the job.

Chris

[Hampus]

Thank you!

I'm not a big fan of drilling all those holes through the hull. One big hole is more than enough and less scary than one big and four small ones. Ball valves is what is mostly used here in Europe and it's even hard to find regular seacocks. I think I'll go with bronze thruhulls and bronze ball valves.

/Hampus

[mike d.]

bronze is the way to go stainless is not good for under water use. lack of oxygen will cause crevice corrosion in the stainless and they will fail almost certainly. stainless needs a steady oxygen supply to maintain it's integrity like aluminum when exposed to oxygen/air it creates a thin film of oxidation on the surface to maintain it's shine if polished or dull finish when not

[s/v Jedi]

Stainless steel ones are for steel boats.

cheers,
Nick.

[James S]

When I put my cockpit drains in I installed two 2" SS thru-hulls with SS ball valves...I did this because I could get them locally and not the proper bronze ones...this was poor planning on my part since most all boat stuff I have to import.
However both these are about 6" above the water line (when at rest)...I always told my self I'll change them out later...but I may just keep them.

[S&S]

Underwater rated ball valves are fine. Spartan makes a good product but I'm slowly replacing all my "cone" seacocks with ball valves.

If your boat is glass or wood, they should be bronze, if steel, steel; if aluminum, marelon.

[barnakiel]

Bronze on wood and plastic. SS on a steel boat.

The ball is often chromed on bronze seacocks (Groco, Apollo).

b.

[David M]

Originally Posted by s/v Jedi

Stainless steel ones are for steel boats.

cheers,
Nick.

...also aluminum boats.

[s/v Jedi]

Originally Posted by David M

...also aluminum boats.

Yes, that used to be the way but I think they switched to Marelon for all new boats now.

cheers,
Nick.

[Laidback]

Marelon comes out TOP just ahead of Bronze

[David M]

My boat has 13 stainless steel thruhull valves. I will NEVER use Marelon again. Last I heard, the CFR's do not allow plastic valves on Subchapter-T boats. My boat has ORV status which means I am exempt from the no plastic valves rules and I still will not use Marelon.

[Hampus]

Thank you for your replies!

How do I test the integrity of bronze thru hulls? Changing all the thru hulls and valves involves a lot of $ and the ones that are already there might, for all I know, not be older than one year, they could also be 30. I don't want to "waste" money replacing what doesn't need to be replaced. There are other holes to put those $$ in.

/Hampus

[S&S]

Originally Posted by Hampus

Thank you for your replies!

How do I test the integrity of bronze thru hulls? Changing all the thru hulls and valves involves a lot of $ and the ones that are already there might, for all I know, not be older than one year, they could also be 30. I don't want to "waste" money replacing what doesn't need to be replaced. There are other holes to put those $$ in.

/Hampus

if the body isn't turning pinkish you're fine from an electrolysis standpoint- they're supposed to be greenish. If they aren't leaking, at haulout remove and grease the cones and reinstall- they're fine. They're seacocks right? Not gate valves or some other such horror?