Replacing seacock, whilst still afloat

[Zhivili]

Dear All,
Despite being only 18 months old, our engine sea cock has broken in that it is permanently in the closed position. I think that the shaft leading from the handle to the ball valve has sheared.
I would appreciate advise as to whether I can change this sea cock whilst still afloat. It is only 18 months old and I am sure will release easily.
Has anyone, for example experiance with freezing the spigot of the inlet pipe. You can get freezing kits, used in the plumbing world, but do they go low enough to freeze sea water ? Alternatively, does a bit of sea water in the boat matter much. Can you take the sea cock off and then quickly put a new one on ? Would a new one have to be prepared with jointing compound (in which case I can see a problem). Alternatively, would a rubber "O" ring or washer between the spigot and valve seal properly.
Local engineers tell me that we have to take the boat out, but being at Port Solent, this is going to be very costly.
Would appreciate any advise on taking a sea cock off, whilst still on the water.
Thanks all.

 

[dnickj]

you coud jump over he side and put a wooden bung in from the outside - but if it all goes wrong the only way is down an will be a lot more expensive than a lift out - you could always try the sea lift at cowes or even drying out if yu can take the ground

 

[whipper_snapper]

I would not want to risk it. But assuming you are fin-keeled, can you not find a wall to dry-out against ?


Since the seacock is stuck closed, you could remove the inlet pipe and run the engine by putting the end in a bucket of water. You just need to secure the bucket well, tie the pipe so it can't jump out, and have someone tasked to keep it full.

 

[fireball]

Hmm - I'd prefer to take the boat out .... however, if I had no choice then a bung from the underside would suffice, altough this won't work if you have a teardrop thru-hull with a grill !! ...

I'm sure there are other ways in which you could minimise the water intake, but it is blummin cold at this time of year ...

Can you not take it to some piles or beach somewehre and dry out?

 

[Orla]

You could get all the parts and tools required for the job and then dry out against a suitable wall.
If you are confident it could be done between tides.

 

[earlybird]

You will almost certainly need a sealant, PTFE tape in all probability. I can't see an "O" ring doing the job as a ball valve is unlikely to screw far enough down to compress it. IF you do try it:-
a) You will be surprised how much water jets up, and how far it sprays, even from a 3/4" skin fitting. Dress in your swimming cossie.
b) Do it when the yard hoist is available, in case you finish up with a poor seal on the threads .
c) Have a tapered wood bung to hand, just in case

I'm not recommending this mind you!
P.S. I'm assuming the seacock is very accessible.

 

[Gothik29]

I've seen a marine contractor replace a ball valve style sea cock while the boat was afloat. He basically removed the old valve and screwed the new fitting on, just very quickly......

It's a similar procedure to removing the paddlewheel log, but it's not something I'd ever recommend. If it goes wrong, it's going to be very expensive and embarrassing.

 

[KenMcCulloch]

I think it's a bad idea. Even if the job went relatively well it would be very difficult to get a proper seal between the valve and the skin fitting with water jetting in as you try to wrap tape or smear sealant around. Dry out or lift out. If you are just replacing the valve from the inside you only need to dry out far enough to uncover the fitting which may increase the range of possibilities.

 

[bazobeleza]

I swapped over a 3/4" seacock whilst at sea, but it was a very wet and messy job, never to be repeated, certainly never with a bigger valve that you,ve probably got on your engine intake.

If it needs doing whilst you are afloat why not disconnect another seacock and run a hose from that to your engine until you can either lift or dry out?

 

[capnsensible]

I changed a hull valve once by being lifted in the yard at the end of their day, in slings overnight and splashed back in at 0800. Was very much cheaper but you need a friendly yard and absolute confidence you've got all the right bits, tools,etc. Or a least some effective bluffing skills.....

 

[bazobeleza]

Have you tried taking the handle off and getting a pair of molegrips locked onto the stub to turn it, a fraction one way then back, gradually loosening it?

 

[stephenh]

Use a tapered wooden ( soft wood !) bung from the outside. I would shape it myself rather than rely on the shop bought taper.

Wrap it in one layer of cloth (something thin like cotton sheet) first - this acts as a sealent (gasket ?) but more importantly it prevents the bung from jamming in....

The main problem that I have had with this method is the fitting spinning when taking off old / putting on new - sometimes you have to have someone on the O/S to prevent this.

Dry suit stuff at this time of year !!

Dry out against a wall ?? - thats the easiest. Good luck.

 

[chanelyacht]

Minor point - if you do it in water, and it goes wrong and you sink, what's the betting you wouldn't be insured ?

 

[Zhivili]

Thank you all for your advise. Following what has been said, I intend to move the boat, by using the engine sea water intake placed into a large water container, and take it somewhere where I can dry the boat out.

What amazed me, is the sea cock has only lasted eighteen months.

Thanks for all of your advise.

Zhivili

 

[KenMcCulloch]

[ QUOTE ]
Thank you all for your advise. Following what has been said, I intend to move the boat, by using the engine sea water intake placed into a large water container, and take it somewhere where I can dry the boat out.

Zhivili

[/ QUOTE ]
Just put a hose over the side to feed the cooling water intake..

 

[saltwater_gypsy]

Since it is the engine intake sea cock, it will be well below the surface. You could sell tickets so that others can share in the drama......thats if you don't lift out.

 

[Dreamcatcher]

Wicor Marine has a scrubbing/drying berth, they are just round the corner towards Fareham.
Call Stuart 01329 237112, sorry I don't know hegiht above chart datum, we have dried out alongside before.

 

[Skylark]

Hard to believe that this is being contemplated. It'll end in tears! No other possible outcome.

Scrubbing wall seems a reasonable approach to avoid the cost of a lift. Have a wooden bung available just in case it takes longer than a single tide. Having a friendly diver standing by isn't a bad idea either.

Please let us know how you decide?

Good luck.

(is the boat 18 months old or just the sea cock? If the boat is new, claim on the warranty and get the dealer to do the work?)

 

[sailorman]

i have done it after the yard engineer ( Gorrilla ) had done the seacock up & stripped the spindle leaving the cock shut.
get prepaired
tools, suitable bung, ptfe ect.
it took about 10 mins with less that 1 Ltr comming aboard.
i did mentally fill in the claim form /forums/images/graemlins/blush.gif
well i just :- /forums/images/graemlins/shocked.gif

 

[Billjratt]

Exactly, it's going to be just a little worse than doing the paddle wheel, which is a standard procedure. If you haven't done it, you should try, then you wouldn't be so twitchy. If it all goes to excretia,you can smack in a bung, and you're no further back than you were.