Sea-cock change - whilst afloat...

I use PTFE tape for sealing threads and don't use two jubilee clips - that's just a ruse to sell twice as many as you need. I do use high quality, all stainless ones though.
In your case, I'd leave it till you're out of the water but keep a suitable bung handy.
 
My heads outlet seacock failed this summer, and it was just short of 16 years old (age of the boat), started leaking whether closed or open. Didn’t investigate too much, pulled the boat out and replaced all the underwater seacocks and skin fittings. Would also not fiddle with it until next lift. Agree with point that if jammed the surveyor should have noted it- in fact would expect a comment such as ‘all seacocks operated as expected’, or otherwise to be in the survey report
 
I would do it next time she is out.
If you do it afloat be sure to have a very large set of stilsons at the ready, and an electric blow torch or a flask full of boiling water and some rags ready. If its tight you can wrap the rags round the seacock and pour on the boiling water - heat may help loosen things up a bit
 
icarusbop said:
My toilet outlet 1 1/2" sea cock has failed in the open position, it's not leaking - I just can't close it...
I'm considering changing it out, with the boat still in the water! The plan so far is to heel the boat so the outlet is above the waterline, put in a bung for good measure and change the cock out with the boat in this position.

I am only changing the sea-cock, not the hull fitting and there is an elbow fitted between the skin fitting and the sea-cock - so due to the angle of the sea-cock there is very little (if any) chance of the skin fitting rotating when I undo the sea-cock. I'm confident the skin fitting will stay secure.

For obvious reasons, I want to be as prepared for any "unforeseen eventualities" as possible.

I'm unsure if I should use PTFE tape or loctite 55 thread tape for the thread seal. There is a lot of support for both options, but I've never tried the loctite 55 cord before.

Any other ideas or suggestions much appreciated.

Regards:

IcarusBop
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A good friend did it with a bog seacock. He sent the bride underneath with a wooden bung, tapped it in lightly. Then did the biz with the valve. Then she removed it. It gives an extra margin of safety.
Stu
 
skipper_stu said:
A good friend did it with a bog seacock. He sent the bride underneath with a wooden bung, tapped it in lightly. Then did the biz with the valve. Then she removed it. It gives an extra margin of safety.
Stu
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The extra margin of safety being the bride or the bung?
 
The OP asked for advise re changing it while the boat stayed in the water , like most here , if he plain to pull the boat out I agree he should wait till he does,
but if he has no plain ,say for another year or two , then there no reason as long as he take care why he can't do it while the boatin the water ,
what make it a bit safer in the OP case is , the sea cock is connected to an elbow and not straight on to the hull fitting ,
so unscrew it as long as he take some care shouldn't disturb the hull fitting or break the seal between the fitting and the hull .
of cause if he as any fear that the fitting has corrosive then he should be looking at hauling out ASAP .
This isn't the job for the faint hearted , and if he can bung the fitting even better ,
And a good size salami kept handy , don't laugh a friend kept his boat afloat for sixty miles with a salami .
 
Last year I replaced all the seacocks (and throughulls) of my boat. For the threads I used Loctite 577. Of course that's a liquid, not a thread but it's good alternative for this job.
 
Thanks for all the support and suggestions.
The vote is split about 50/50 for leave it until the next lift - perhaps I should have put vote option on the post...
There are disadvantages to doing it out of the water also - you don't know if it's going to leak when you re-launch, raising the possibility of lifting back out again (at extra cost).
Also - I don't plan on lifting soon, and wonder what the risk is if I leave it in it's current state, perhaps this would give the insurance a get out the pipe failed and the vessel sank?

Peoples main concern is rotational force on the skin fitting might affect the seal, since my skin fitting has an elbow between it and the sea-cock, no rotational force will be transferred to the skin fitting. Only angular force - this can be countered by a large stilton wrench on the elbow itself to reduce and force transferred to the skin fitting.

I'm still considering giving it a go - with an extra check in the process; once the boat is heeled and the hole bunged (for good measure) I can test the fitting to see if it looks like it might come off without too much effort (give it a tweak) - if it looks good I'll chop the pipe and quickly change the fitting, once the new fitting is on the new pipe can be sorted later. If it looks solid and needs more effort to remove the old unit I can back out the plan and wait until my next lift.

Still working on options and required parts / backups parts / backup backup parts...
 
I replaced a sea cock whilst out of the water last winter. Didn't think I'd disturbed the skin fitting but after launching I had a small leak necessitating lift out, rectify and relaunch. Cost me quite a lot but if I'd done it whilst afloat I'd still have had the same.
 
Did mine last week(out of water for obvious reasons.). remove screws internally, outside small bar with hammer two/three small hits and out she came. sanded and new grease, will be fine now. could never budge it from inside with handle.

Steveeasy
 
icarusbop said:
Peoples main concern is rotational force on the skin fitting might affect the seal, since my skin fitting has an elbow between it and the sea-cock, no rotational force will be transferred to the skin fitting. Only angular force - this can be countered by a large stilton wrench on the elbow itself to reduce and force transferred to the skin fitting.
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Or the elbow bend or skin fitting is so de-zinc'd that something breaks when you start applying force.
 
lpdsn said:
Or the elbow bend or skin fitting is so de-zinc'd that something breaks when you start applying force.
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One would think if the OP is going to take on a job which involve chancing it while in the water , he the type of guy who could tell by looking and tapping the fitting before removing it , and if it was that bad he haul out ASAP .
He said already in his posting , he will slowly see if it will move easily before doing the job , reading post #32 the OP comes over as someone who had a plain .
What the worst that going to happen , if he break the fitting as long as he bung It from the out side or at the very less have some thing he can stop the leak from the inside he not going to sunk .
If the break the seal between the fitting and the hull , he get a small drip nothing that some sealer won't slow down ,
There been a few cases I know where owner have sailed the rest of the season with a slight slip of a leak .
Anyway both cases mean he have to get hauled out .

The job is bein done in the Marina what I would suggest is do the job on a working day , if in the worst case you do need to be hauled out you can .

Not sure if you going to heel it over enough to get the water level below the fitting tho ,

This is not a job for everyone , but with some care and if you not the type who going to have an heart attack when some water pop through the open fitting , there no reason why the job can't be undertaken .

Of cause if the OP was plainning to be hauled out soon he be just as well to leave it tell then .
 
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I don't doubt that seacocks can and are changed whilst in the water and i'd suspect they are done afloat for a reason. If it's leaking, looks like it might fail, stuck closed etc. But, in he case of the OP, it's stuck open, not leaking and not causing any problems.

So, the real question should be "why do it afloat, as opposed to waiting until the next lift out" ?

No matter how small the risk of something going wrong, it's a risk that does not need to be taken.

But we're missing something here. If the ball valve is stuck open, it's almost certainly going to be calcium buildup or maybe even a family of barnacles stopping it closing. If the OP is correct in his belief that he can careen the boat enough to get the skin fitting clear of the water he can stick a bung in it. Then use a hot air gun on the hose to remove it. A scrape around to remove the worst of whatever is in there, followed by a dose of something to dissolve the rest and there will likely as not be no need to change the fitting at all.
 
PaulRainbow said:
I don't doubt that seacocks can and are changed whilst in the water and i'd suspect they are done afloat for a reason. If it's leaking, looks like it might fail, stuck closed etc. But, in he case of the OP, it's stuck open, not leaking and not causing any problems.

So, the real question should be "why do it afloat, as opposed to waiting until the next lift out" ?

No matter how small the risk of something going wrong, it's a risk that does not need to be taken.

But we're missing something here. If the ball valve is stuck open, it's almost certainly going to be calcium buildup or maybe even a family of barnacles stopping it closing. If the OP is correct in his belief that he can careen the boat enough to get the skin fitting clear of the water he can stick a bung in it. Then use a hot air gun on the hose to remove it. A scrape around to remove the worst of whatever is in there, followed by a dose of something to dissolve the rest and there will likely as not be no need to change the fitting at all.
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Paul your idea is good and with a bit of luck might work unless it rusted in place or he ends up braking the handle ,
but unless he try he won't know .
You first point tho , the OP as said he as no intention of haulout any time soon , and althought the seacock is in the open stage and he can use it , he is unable to close it when he leaves the boat .
Ok he could bung the fitting every time he leave the boat for any length of time :)
 
sailaboutvic said:
Paul your idea is good and with a bit of luck might work unless it rusted in place or he ends up braking the handle ,
but unless he try he won't know .
You first point tho , the OP as said he as no intention of haulout any time soon , and althought the seacock is in the open stage and he can use it , he is unable to close it when he leaves the boat .
Ok he could bung the fitting every time he leave the boat for any length of time :)
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The boat is only 14 years old Vic, so i'd think there's a reasonable chance it'll free off, whenever he decides to do it, i'd at least try freeing it off. Not sure what he means by not planning to lift out anytime soon, i'd expect it to need a lift out early part of next year for antifoul, as it was surveyed in March this year, unless there was a delay in launching.

Fair point about not being able to close the valve when leaving the boat.
 
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