Seacock: Bronze or Marelon

[captmikecoin]

I need to replace a broken bronze seacock. Should I replace it with bronze (hard if not impossible to find in Greece) or Marelon which is also difficult but may be available?

All advice gratefully received.

Mike

[SVTwilight]

I replaced all my bronze seacocks with Marlon 9 years ago and never looked back. Much less maintenance and totally reliable. Just regularly use the lube the recommend.

[KISS]

This might be of some use in deciding:

What Marelon Is

Basically, bronze is stronger, but Marelon avoids corrosion issues (incl. galvanic).

[HopCar]

I'm not a big fan of plastic seacocks but a lot of people use them without problem.
Forespar makes two styles of Marlon seacock. The one they sell to the aftermarket has a triangular base and I think the stem is undersized and can break.
Flange Mounting Seacocks

The other one they market to boat builders. I couldn't find it on their website but it has a round base and seems much better made. Even though Forespar doesn't try to sell this to end users, any Forespar dealer can order one for you.

If I were replacing a seacock today, I'd use Groco products. I think they are a good value.
Seacocks by Groco and Apollo Conbraco

Priority mail shipping from the USA to Greece might not be too bad. Send me a PM if you'd like a quote.

[Cheechako]

Bronze. Never Marelon for me. Been there, done that.

[zboss]

What about a bronze through hull and a marelon ball valve?

[HopCar]

Zboss, a lot of people put ball valves on thru-hull fittings but it's a weak
installation. The thru-hull is unsupported and could break. The threads don't match and there is only a few threads holding the ball valve to the thru-hull. This would be an even weaker installation with a plastic ball valve.

A real seacock with a mounting flange, wether Marlon or Bronze would be much stronger.

[kas_1611]

We got rid of our cheap brass seacocks a couple of years ago for Marelon ones (with the exception of the engine water intake which had to be metal so became DZR). Marelon is not maintenance free as you still need to watch for signs of corrosion on the bolts but as trying to get genuine Bronze ones proved to be almost impossible due to the quantity of cheap freshwater brass around I went with something I could trust not to corrode.

Top Tip: Freshwater brass or domestic plumbing valves and fittings will not have CR embossed in them and will generally have red handles. DZR will have CR and Green handles. Not seen genuine Bronze so can't say what they have.

Sadly due to the inadequacies of the EU Recreational Craft Directive (RCD) stating that underwater fitments should last at least 5 years builders have been cutting costs and fitting the cheaper brass rather than more suitable alternatives. Brass may last 5 years but there have been cases of thru-hulls etc falling apart from de-zincification after a very short time.

Any of the online chandleries should be able to post you a ball valve to any EU country for a few quid

Originally Posted by SVTwilight

I replaced all my bronze seacocks with Marlon 9 years ago and never looked back. Much less maintenance and totally reliable. Just regularly use the lube the recommend.

What is the recommended lubricant? Is it Marelon specific or something generic?

Cheers

Keiron

[TKDSailor]

Originally Posted by captmikecoin

I need to replace a broken bronze seacock. Should I replace it with bronze (hard if not impossible to find in Greece) or Marelon which is also difficult but may be available?

All advice gratefully received.

Mike

We've been using Marelon for years with no problems- bronze is NOT GOOD on steel boats due to corrosion issues.

[savoir]

Originally Posted by kas_1611

We got rid of our cheap brass seacocks a couple of years ago for Marelon ones (with the exception of the engine water intake which had to be metal so became DZR). Marelon is not maintenance free as you still need to watch for signs of corrosion on the bolts but as trying to get genuine Bronze ones proved to be almost impossible due to the quantity of cheap freshwater brass around I went with something I could trust not to corrode.

Top Tip: Freshwater brass or domestic plumbing valves and fittings will not have CR embossed in them and will generally have red handles. DZR will have CR and Green handles. Not seen genuine Bronze so can't say what they have.

Sadly due to the inadequacies of the EU Recreational Craft Directive (RCD) stating that underwater fitments should last at least 5 years builders have been cutting costs and fitting the cheaper brass rather than more suitable alternatives. Brass may last 5 years but there have been cases of thru-hulls etc falling apart from de-zincification after a very short time.

Any of the online chandleries should be able to post you a ball valve to any EU country for a few quid




What is the recommended lubricant? Is it Marelon specific or something generic?

Cheers

Keiron

Superlube does a great job on Marelon. Strip and rinse the parts every two years. Check the O ring for perishing and if it's OK smear it with a little Superlube. Dab a tiny bit of grease on the bearing under the handle.

Assemble and forget for two years except for giving every handle a wiggle every few months.

[Cheechako]

Originally Posted by zboss

What about a bronze through hull and a marelon ball valve?

The opposite would be preferred to me. It's the valve that is often the issue. I replaced a Marelon assy once and the thru hull is tough as nails. I had to cut it out with a hack saw blade piece at a time. Couldnt get it with a cold chisel and hammer.

[s/v Jedi]

https://youtu.be/l5ajZ3nfzzQ

check his related videos as well

[savoir]

Perko ball valves are made of nylon inside a bronze casing. Not sure if that's all or some of them. It makes cleaning so much easier and eliminates pitting of the ball.

[reed1v]

We always preferred solid bronze for two reasons: Strong, and a good way to detect stray corrosion inducing currents on the boat. Someone mentioned they had brass seacocks. That would be a disaster and should be immediately replaced. A lot of cheap boats have old fashion galvanized gate valves which really should not be on any boat.

[seasick]

We've heard and read of vessels having their bronze seacocks blown off by lightening. I have heard this is not an issue with Marlon valves. I don't know if such a rare occurrence should factor into your choice of materials. We have had both. When the Marlon valves stick at sea, they worry the heck out of me. I wouldn't try to force them as I might with a bronze valve.