Seacock and through hull plastic/ steal / other

[AJAL]

Hi all,
I would value any feedback on which material to choose when replacing seacocks and their through hulls. I have seen SV Impavidus recent youtube in which brass seacocks installed on a relatively new bavaria failed. I am thinking plastic for all my seacocks and through hulls. Any benefit in steal? Other material?
Cheers
Joel

[George_SD]

Honestly,
Marelon and Bronze are good options, provided they are properly installed, exercised and lubed once in a while. I don't have any experience with SS seacocks or valves. Any of them will last many years without issues. The brass stuff has not been great and does leach zinc which causes it to weaken significantly faster. I would not put any new brass seacocks, valves or fitting - only bronze or marelon.

This is a good thread to read/watch. https://forums.sailboatowners.com/th...enough.136999/

[double u]

Originally Posted by dr.j.levy

Hi all,
..... Any benefit in steal?

...the cheapest by far...

[Gard]

I would only conscider composits. There is a great variance in the quality of brass (even within the same brand some times). Much of the available brass is also of poorer quality than decades ago. Some sort of mishap in your electrics can also eat them up in no time. Composits from a reputed brand is more durable and reliable than the brass from the most reputed manufacturer. Although that brass is good as ever, the composits is still better.

I don't really know - this is what I've picked up from here and there. I'm under the impression that this is also the general consensus.

Even if brass is good enough in most cases (as it has been for ages and ages), if plastics are even more sound - that's what I would go for. I mean, a thru hull fitting that fails can sink your boat - or at best lead to a scary, expensive and tiresome event and clean up After all, there shouldn't bee enough of those fittings to break the bank? Buy what gives you the soundest sleep. From what I hear, plastic composits is the way to go.

[AiniA]

A couple of things to consider. First, you are talking about bronze, not brass. Brass would not last long at all in salt water. Have a look at Trudesign fittings from New Zealand, composite and strong with excellent engineering. Also they are like half the price of quality bronze fittings.

[Manateeman]

We had a Marelon seacock fail open. We would never recommend any plastic .
Just the opinion of professional boatbuilders.
The manatees

[svhydra]

hi; my insurance company informed me any thru hulls below the water line that were plastic would void my policy. might be worth looking into before you decide what to use. all the best; R

[deblen]

https://www.cruisersforum.com/forums...ll-267705.html

[HopCar]

I sold marine supplies for almost fifty years. I was a distributor for Groco, Perko, Apollo, Wilcox-Crittenden, and Forespar.

I would never put European DZR brass on my boat. I also would not use Forespar Marlon seacocks that are sold retail. The ones they sell to boat builders only are not awful. The plastic seacocks distributed by Raritan are pretty good as well.

If I was installing a seacock today, I’d use either the Groco imported or the Groco American made seacock and bronze thru-hull. The Groco flange adapter and ball valve is also a good option. I’d also use a Groco backing block.

[goboatingnow]

Originally Posted by HopCar

I sold marine supplies for almost fifty years. I was a distributor for Groco, Perko, Apollo, Wilcox-Crittenden, and Forespar.



I would never put European DZR brass on my boat. I also would not use Forespar Marlon seacocks that are sold retail. The ones they sell to boat builders only are not awful. The plastic seacocks distributed by Raritan are pretty good as well.



If I was installing a seacock today, I’d use either the Groco imported or the Groco American made seacock and bronze thru-hull. The Groco flange adapter and ball valve is also a good option. I’d also use a Groco backing block.

Good quality DZR made to appropriate standards has a service life measured in decades but we’ve already had tens of pages on this

If you are in Europe there are a number of high dzr and bronze sea cock fittings that can be sourced maestrini make easy some of the best fittings on the planet and are distributed by SVB and others. These are proper BSP threads etc.

[deblen]

Brasses and bronzes – Cox Engineering

[smj]

Marelon are fine as long as you follow the manufacturers recommendations.

”MAINTENANCE:FORESPAR[emoji768] MARELON[emoji768]Thru-hull/seacocksarecorrosionfreeandpro- vide great peace of mind in that regard. They are relatively maintenance free. Generally, lubrication is not required. What is required is to open and close them on a regular basis (4 times a year minimum). ”
If your unable to follow the recommendations the answer would be to negate all under the waterline thru hulls?

[goboatingnow]

Originally Posted by smj

Marelon are fine as long as you follow the manufacturers recommendations.

”MAINTENANCE:FORESPAR[emoji768] MARELON[emoji768]Thru-hull/seacocksarecorrosionfreeandpro- vide great peace of mind in that regard. They are relatively maintenance free. Generally, lubrication is not required. What is required is to open and close them on a regular basis (4 times a year minimum). ”
If your unable to follow the recommendations the answer would be to negate all under the waterline thru hulls?

What’s the implications for insurance as it was mentioned to me that installing plastic in replacement of metal has insurance implications

For a boat subject to the RCD , it would require the fittings to pass ISO tests for fitting and assembly strengths.

[Matt Johnson]

The Forespar 93 series seacocks meets ISO and ABYC standards.

[smj]

Originally Posted by goboatingnow

What’s the implications for insurance as it was mentioned to me that installing plastic in replacement of metal has insurance implications

For a boat subject to the RCD , it would require the fittings to pass ISO tests for fitting and assembly strengths.

Never had a problem with insurance, but the last 5 boats we’ve owned have no underwater thru hulls.