Check your Seacocks, Folks!

Stemar

Stemar

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Jazzcat is out of the water for the winter, so one of today's jobs is to check the seacocks. One looked particularly iffy, and the handle came away in my hand, so time to change it. I grabbed the hose and gave it a tug to see if it was going to come off without a fight. This is what happened

1643749121866.png
:eek::eek::eek::eek::eek:
It was somewhere it wasn't going to get thumped, but I wonder how much longer before it just fell off by itself and sank the boat!

All the others are plastic or survived a good welt with a hammer, but there is one more I'll change before we go back in.
 
burgundyben said:
How old is that?
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Presumably original, so 38 years.
Buck Turgidson said:
you didn't notice that earlier???
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It's the drain for the holding tank, so it doesn't get used at the moment. I knew it needed sorting out, but I didn't realise it was that bad. All the through hulls and seacocks on my old boat were bronze, and virtually indestructible, so I made a potentially very expensive assumption about this one. I'm guessing it's DZR to have lasted this long; I'd have expected ordinary brass to have failed years ago. Maybe it did, and this is the second or third.

superheat6k said:
Forespar Marelon - it does not corrode.
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I would have, but the chandlery didn't have them in the right size. I didn't want to leave it unfixed because I have a fixed lift in date and jury service coming up in a couple of weeks, which could put a crimp in my projects.
 
Stemar said:
Presumably original, so 38 years.

It's the drain for the holding tank, so it doesn't get used at the moment. I knew it needed sorting out, but I didn't realise it was that bad. All the through hulls and seacocks on my old boat were bronze, and virtually indestructible, so I made a potentially very expensive assumption about this one. I'm guessing it's DZR to have lasted this long; I'd have expected ordinary brass to have failed years ago. Maybe it did, and this is the second or third.


I would have, but the chandlery didn't have them in the right size. I didn't want to leave it unfixed because I have a fixed lift in date and jury service coming up in a couple of weeks, which could put a crimp in my projects.
Click to expand...
That is plain brass -DZR does not dezincify. Until recently skin fittings were not made in DZR as the material was originally developed for domestic plumbing which does not use skin fittings. So often you would get DZR or even bronze valves with plain brass fittings. Failure through dezincification is almost always in fittings and usually in the threads just like yours. Failure of valves is very rare as the body is not exposed to seawater, although spindles and balls do fail.

Replace with all DZR, or if you have the space consider Tru Design. Forespar Marelon is not really practical, good though they are as they are a different design and not a direct replacement for BSP type fittings. Tru Design are, although the bodies are generally larger than metal ones so might not fit in confined spaces.

I am faced with just this on my Bavaria as the buyer's surveyor has found pink patches on the outside flange of the loo seacocks. Doubt there is anything wrong with the threads - it is only 6 years old. Inevitably though insurers will require perfectly sound valves and fittings replaced. If I do it rather than the buyer, it will be DZR as I know there is not enough room for Tru Design as we looked at this when the boat was new.
 
I had a similar experience, Viv Cox put the pics on his site for an example of dezincification it was soo good, now all replaced with plastic and a relaxed care free attitude now.
 
We recently had to lift out for our owners cabin heads seacocks to be replaced along with all the hoses as the outlet was solid scale. We took the opportunity to add a diverter valve so that pure liquid effluent could be sent packing without taking a holding tank tour first. Our original seacocks and skin fittings were hefty stainless ball valves and had seized from lack of regular manipulation as we never normally close them with the heads being above the waterline. I imagine the stainless ones removed were not originals as the boat is 1986 build. Structurally the removed stuff was sound, just seized solid with scale. The job in our case was done in the boatlift by our excellent yard guys who had suitable custom tools to help but it still took some 6 hours from start to finish including a comprehensive pressure wash and the return trip to/from our berth.
 
Stemar said:
All the others are plastic or survived a good welt with a hammer, but there is one more I'll change before we go back in.
Click to expand...

Don't rely for very long on the hammer test. Surveyor 7 years ago hammer tested mine but suggested I replace them due to age. 11 months later, one broke up with little force when I tried to remove it. All underwater ones replaced with TruDesign.
 
Had a few of those on ours - at least one was that bad (split along the skin fitting threads upon non-destructive handling/inspection!). They were labelled ‘replaced 2002’.

Replaced with TruDesign.
 
Stemar said:
Presumably original, so 38 years.

It's the drain for the holding tank, so it doesn't get used at the moment. I knew it needed sorting out, but I didn't realise it was that bad. All the through hulls and seacocks on my old boat were bronze, and virtually indestructible, so I made a potentially very expensive assumption about this one. I'm guessing it's DZR to have lasted this long; I'd have expected ordinary brass to have failed years ago. Maybe it did, and this is the second or third.


I would have, but the chandlery didn't have them in the right size. I didn't want to leave it unfixed because I have a fixed lift in date and jury service coming up in a couple of weeks, which could put a crimp in my projects.
Click to expand...

Holding tanks as standard 38 years ago!

I'm very impressed

And obviously ......... questioning

Jonathan
 
Just replaced the remaining 4 thru-hulls of mine that were not already Tru design.
Having said that, the old DZR fittings seemed reasonable when I ground them out, however, I had a routine hull survey a couple of months ago and agreed with the surveyor replacement was worth it based on age (the boats' not mine...). The seacocks though were not brilliant so feeling better now.

I looked at Forespar but they seem to be much more expensive ?

Ordered them all online and got them a few days later
 
Take care with the choice of plastic, one of our members has a plastic fitting fall apart in his hands during an earlier debate, causing a flood. Sorry I can't remember which of the two it was, does anyone recall this?
 
doug748 said:
Take care with the choice of plastic, one of our members has a plastic fitting fall apart in his hands during an earlier debate, causing a flood. Sorry I can't remember which of the two it was, does anyone recall this?
Click to expand...

Although there may be some failures, I've never heard of any with TrueDesign. IIRC there was a problem with Marelon a few years ago with handles failing but think design was changed.
 
I doubt very much that the failed valve was DZR. When your boat was built, about the same time as mine, DZR was very new, developed by the plumbing industry for use in soft domestic waters. It did not reach the marine market other than Blakes seacocks for some years later. It would have the CR mark cast in if it was.
 
too late , my motorboat partially sank last winter..
The boat yard that owned it (it was a hire motorboat on the broads) built the holding tank over the old seacocks.. I didn't even know they were there..
 
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