Seacock warning, probably most relevant to Australians

[GILow]

Originally Posted by Quadrille in JB

Last week I noticed that my generator was not pumping its usual amount of water through the exhaust. The sea strainer was clean so I removed the hose from the GROCO seacock. The valve’s handle action felt fine but water flowed freely in both open and closed positions. The shaft had apparently broken with the valve in the mid position. I worked it open further with a Phillips screwdriver so the genset would get adequate flow. This will be #1 on my replacement list at the next haul out. Valve is about 5 years old. So much for quality bronze valves.

That’s exactly the way my unbranded version failed.

[GILow]

Originally Posted by Manateeman

Hi. Marelon is the Forespar name for Zytel. I was fooled into thinking it is a reliable seacock and I’m a boatbuilder with 60 years of experience. Please. Just google the failures...broken handles, frozen open, frozen closed. No lubrication fitting. Hidden stainless pins. Some people who haul every year and work these valves back and forth...some have no issues.

Boatbuilders very rarely discuss major errors even among other builders but I made a huge mistake with marelon seacocks. Please, please read the prior threads. Jedi and another member sent me information as we have an aluminum hull. We will use Groco stainless flanges. Use the best ball valves you can afford.

I’ve used Apollo seacocks without fail on glass hulls. Please stay clear of marelon. Regards, Mark the manatee

Caution noted. I will do some more reading.

[GILow]

Originally Posted by HankOnthewater

Hi Gilow, I have a tub full of bronze fittings and seacocks, came with the boat, have even some of the stuff Jedi posted. No, it is not the variety you complained about. I believe all made in USA and France. If you let me know via PM what size you want, will post that, because I never going to need it all.... that is if you want to stick with bronze.

Thank you, but I think it would be best if I sailed over to check the fit on site. That will save on postage too.

[GILow]

Originally Posted by JPA Cate

Strong, reliable and foolproof.



....mmmmMaybe not damn fool proof, though.



Ann

As we all know, anytime they make something foolproof someone just goes and invents a bigger fool.

[Wotname]

This thread sort of reminds me of the other threads along the lines of - do you close your seacocks regularly

It would seem to me that those who do would have less of these surprise moments (failed seacocks etc).

[Manateeman]

One last suggestion. Professional Boatbuilder (proboat.com) articles can be searched by subject. For example - seacocks.
Here one can easily source the collective professional expertise and opinions of builders and marine surveyors. Letters in response to articles, also contain much valuable information. Workboat and National Fisherman are also excellent.
I have never seen a seacock failure in true bronze seacocks from Buck Algonquin, Apollo, Spartan, Perko, or Groko, in any glass vessel where the seacocks were properly installed. My personal preferences : serious backing plates, thru bolted and no bonding wire. For aluminum, TIG welded 1/2” backing plates, isolation gasket, Groco flange and a quality ball valve. Again, I regret using marelon.
Advice from a USCG qualified vessel safety coordinator, and old boatbuilder.
Mark the manatee.

[GILow]

Originally Posted by Wotname

This thread sort of reminds me of the other threads along the lines of - do you close your seacocks regularly

It would seem to me that those who do would have less of these surprise moments (failed seacocks etc).

The thing is, I do close them. Religiously. I don’t have comprehensive insurance so I’m paranoid.

But closing the handle, as it turns out, was doing nothing other than rotating a shaft stub.

Perhaps the mantra needs to become, close your seacocks AND THEN check if they are actually closed by loosening their hose clamps and pulling off the hose?

[Wotname]

Originally Posted by GILow

The thing is, I do close them. Religiously. I don’t have comprehensive insurance so I’m paranoid.

But closing the handle, as it turns out, was doing nothing other than rotating a shaft stub.

Perhaps the mantra needs to become, close your seacocks AND THEN check if they are actually closed by loosening their hose clamps and pulling off the hose?

The exception proves the rule eh .

Curious - did it feel the same as the others?

I suppose one can tell if the seacock is open or closed without removing the hose???

You experience makes a good point in looking more deeply than just turning a handle - a good thing to remember!

[Oceansailor]

Bronze seacocks fail as they are not 100% bronze. More or less all manufacturers uses a brass stem and a brass ball in a bronze housing. The brass parts acts as an anode and corrodes. Stem breaks and you get the handle in your hand. If anyone knows a manufacturer that actually do not use brass parts I’m interested. I have so far not been able to find anyone....

[Wotname]

Originally Posted by Oceansailor

Bronze seacocks fail as they are not 100% bronze. More or less all manufacturers uses a brass stem and a brass ball in a bronze housing. .........

If you are referring to bronze ball valves, then it isn't too hard to find them with either bronze balls or stainless steel balls.

Here is one but there are many others.

https://www.zetco.com.au/item/180-10...f-lever-handle

[GILow]

Originally Posted by Wotname

The exception proves the rule eh .



Curious - did it feel the same as the others?



I suppose one can tell if the seacock is open or closed without removing the hose???



You experience makes a good point in looking more deeply than just turning a handle - a good thing to remember!

In retrospect, it was moving a lot more freely. If I’d questioned it I suspect I’d have put it down to being a bit worn.

[deblen]

And now..to really confuse things,I am posting this link regarding some bad experiences. I post these comments for information only. / Len


DEfective Seacocks - Page 2 - Trawler Forum

[millsie]

If there are other metals as through hull fittings ,
that is shafts, p brackets, Y brackets , Trim Tabs engines etc

Then the bronze Seacock will be scarificed if not at the same potential as the bonding on the vessel despite having no shore power.
the only exception is on some older wooden vessels.

[David B]

On this, and in view of the mention that stainless steel valves are now commonly available at chandleries, does anyone have any issues/experience using stainless seacocks?

[Wotname]

Originally Posted by millsie

If there are other metals as through hull fittings ,
that is shafts, p brackets, Y brackets , Trim Tabs engines etc

Then the bronze Seacock will be scarificed if not at the same potential as the bonding on the vessel despite having no shore power.
the only exception is on some older wooden vessels.

Curious, what is the galvanic circuit when using un-bonded seacocks?