Seacock maintenance/repair whilst afloat.

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James_Calvert

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The recent post on seacocks got me thinking. What to do when they fail? The worst I've had is a Blakes nearly seize up... I removed the cone, popped in a wooden plug whilst I regreased it and put it back in again. Only possible because it wasn't quite seized, and the Blakes design is pretty robust and unlikely to fail elsewhere during the process. But what about if a gate valve had stripped its internals, or a ball valve had seized? OK I guess with my annual maintenance regime, at least I could get a gate valve apart, but there would be little point unless I had an identical spare from which to rob the innards (and I don't). And a ball valve has no serviceable parts anyway does it? So the only option would be repair by replacement. But I wouldn't want to do this whilst afloat unless I knew I could get it off easily, without damaging the skin fitting. So perhaps I ought to be including gate valve/ball valve removal and replacement in my annual maintenance regime? Or else accept that if one of these fail I can't safely do anything about it whilst afloat.
What does the forum think?
 
James_Calvert said:
The recent post on seacocks got me thinking. What to do when they fail? The worst I've had is a Blakes nearly seize up... I removed the cone, popped in a wooden plug whilst I regreased it and put it back in again. Only possible because it wasn't quite seized, and the Blakes design is pretty robust and unlikely to fail elsewhere during the process. But what about if a gate valve had stripped its internals, or a ball valve had seized? OK I guess with my annual maintenance regime, at least I could get a gate valve apart, but there would be little point unless I had an identical spare from which to rob the innards (and I don't). And a ball valve has no serviceable parts anyway does it? So the only option would be repair by replacement. But I wouldn't want to do this whilst afloat unless I knew I could get it off easily, without damaging the skin fitting. So perhaps I ought to be including gate valve/ball valve removal and replacement in my annual maintenance regime? Or else accept that if one of these fail I can't safely do anything about it whilst afloat.
What does the forum think?
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The worst that happens with most is that they shear off - therefore a softwood bung will sort things out temporarily.

I have careened a yacht in its pontoon berth to change a seacock - but it was a Sadler 25 and I used the spinnaker halliard to a nearby strongpoint to get the appropriate amount of 'lean on'. It wasn't difficult - but I am not sure I could do it with the 11 tonnes of 39' boat we have now.
 
James_Calvert said:
TOK I guess with my annual maintenance regime, at least I could get a gate valve apart, but there would be little point unless I had an identical spare from which to rob the innards (and I don't).
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I have one gate valve on our boat and it is in a non-critical, non-thru hull position. I do have the innards for a replacement, so why not get them? I'd remove all the gate valves. Period.

Otherwise, I think your idea of routine preventive maintenance is the proper and cautious approach.

If one goes, there are wood bungs, nerf balls and other "stuff it in the hole" ideas out there.
 
I lubricate and check all my through hull valves, every year.

Recently some acquaintances with a 7-year-old Sun Odyssey DS had the raw-water inlet come apart in their hand (fortunately after the boat was on the hard), breaking off above the fixing nut but below the valve. Apparently a not-uncommon failing with BenJans of a certain age. Bavs don't use brass so they're in the clear.
 
Gate valves should never ever be anywhere near a boat, I am sure by searching the forum you will find out why. Replace as soon as you can.
 
charles_reed said:
From the bits of work I've done on Bavs, they use good quality components, whatever comments people make about them.
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It is my recollection from the YM seacock campaign that Bavaria was one maker who used dezincification resistant seacocks. I don't recall whether it was DZR or bronze but I don't remember any failures. Perhaps Nigel could check some of his ball valves for the CR mark?
 
Thanks to all who commented. To summarise: the skin fitting itself is a potential failure point, but in the worst case I should still be able to plug it. Preventative maintenance is good practice for gate valves. If I keep them, some spare innards would be a good idea.However, as I expected, the received wisdom is that I should still replace them as soon as I can, notwithstanding the fact that the existing ones have survived some 26 years without failure as a result of adequate annual maintenance.
Nonetheless, I know I 'll want to replace them sometime. So, to return to the theme of my original questions, lets assume they are now bronze or equivalent ball valve types, is there any useful annual maintenance regime, or should I just make sure I can easily get them off the skin fittings for when they eventually seize up and/or shear the connection with their handles? Or realistically, can I just fit and forget them for the next 20 to 30 years?
What do Bav owners, with their acclaimed quality fittings, do?

(Obviously I don't need any advice on maintenance if I replaced them with new gate valves...)
 
I've changed a 3/4" one whilst afloat but it was seized shut so no water ingress when pipe removed, only when it was off the skin fitting and producing around 2-3ft fountain. SWMBO wasn't too happy to say the least but I would do it again to save the cost of lifts.
 
In theory most ball valves can be disassembled for checking but there is little maintenance that can be done. The ball turns in plastic seats but I doubt if you could buy new ones as the whole assembly is so cheap. The ball on many, apparently even on bronze bodies, is either chromium or nickel plated brass, which could deteriorate after years. One of mine, on the galley sink drain, is probably 27 years old and still works OK.

It's the threaded parts of the skin fitting and hose tail that are most at risk, as these are thin sectioned. Dezincification here can penetrate right through quite quickly. Heave on the hose and see if these break off, as I know many on these pages have done by accident.
 
vyv_cox said:
... there is little maintenance that can be done... one of mine ... is probably 27 years old and still works OK...It's the threaded parts of the skin fitting and hose tail that are most at risk, as these are thin sectioned. Dezincification here can penetrate right through quite quickly. Heave on the hose and see if these break off..
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Thanks Vyv, useful advice as ever, meant to acknowledge it earlier. James
 
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