Another Changing Sea cock while afloat thread?

[Boatyarddog]

Hard to believe that anyone with repair experience would proclaim that this type of repair is " easy, or " no problem".
This is not a sea cock, it's a threaded thru Hull with a ball valve. https://www.fisheriessupply.com/plum...s-and-seacocks
If the ball valve is difficult to rotate, you will most likely turn the entire assembly and risk a leak, or worse.
If you have enough room below the valve you might be able to use a pipe wrench to hold the thru hull and loosen the valve, risky though, as the threads on the ThruHull can cave in if they are corroded.
If the valve is already loose I'd wonder why, as they usually are not.
You could careen the boat if your in a tidal area, and change it.
I'd save a few bucks and not risk the possible stress of breaking something off in vitro and have to emergency haulout.
This in vitro change out is something that works or not depending on the situation.
I'd say don't risk it unless you have a solid backup plan!
Cheers
SV Cloud Duster

[DaleM]

I have drilled a hole in the boat and installed a thru hull and valve while the boat was in the water. It is not for the faint of heart or unprepared.

In your situation you must first know if the valve will easily unthread loose without breaking the hull/flange seal on the thru hull. Second you need the correct replacement valve with the correct threads. If the previous owner has the wrong threads on the valve then removing it will damage those threads and make putting the new on difficult. I would have a spare thru hull and sealant just in case.

So how to seal the thru hull before working on it? A sponge, or nerf ball. Dive down, compress the ball hard and very firmly stuff it in the thru hull, come up and do your work and then dive down and remove. It will leak but slow the leaking. Thru hulls have ribs inside to allow a tool to hold it in place while someone turns the nut on inside the boat and that makes it hard to seal with round objects.

By the way a version of this can be used if you had any type of hole in the hull. You can also squeeze and soak the sponge in epoxy first if something punches a hole in the hull and you need a semi-permanent solution. It will probably still leak some though.

You know of course this is a crazy idea and you shouldn't do it, but you are thinking of doing it any way so good luck. So if it all goes poorly, I have publicly told you that what you are going to do is crazy! By the way before I did it I moved the boat into a very shallow slip so I could stand on the bottom. Swimming while placing the sponge in will be even more difficult and if something goes wrong, it can only sink so far!
Dale

[sy_gilana]

I have done this on a 2" head discharge valve and thru-hull fitting. The boat was a 1930's wooden vessel built in Kiel. The job was in a marina in the Azores.


These were the steps.


1 All movable weight to opposite side.
2 Careen over with bow and stern lines in line, and a halyard to adjacent dock, in order to raise the work to a more comfortable depth, to use a mask and snorkel not scuba. Also reduces immensely the flow, if any. (total about 1 cup)
3 Diver places internal wrench in from outside and holds.
4 Internal backing nut is tested for movement or not.
5 Diver places bung into outside and hammers home, it will not be re-used.
6 Hose and seackcock removed by sawing off thru-hull close to backing nut.
7 Nut now removed with hammer and chisel while locking thru-hull internally.
8 LARGER bung placed into INSIDE of thru-hull

9 With foot pressure against inner bung (A firm kick), the whole thru-hull is swiftly pushed out till the big bung seals the hull hole from the inside.

10 Diver removes thru-hull remnant off big internal bung that is now protruding.
11 Diver provided with sealant loaded and pre bunged (on outside) thru-hull and locates it on the same inner bung as in 10.
12 On a timed count, diver hammers on external bung, and inside bung is pulled inward, the whole bung-thru-hull-bung assembly slides home.
13 Inner bung removed.
14 Backing plate fixed
15 Retaining nut fitted
16 Sea cock screwed in while retaining thru hull with pipe wrench.
17 Sea cock closed.
18 Outer bung removed.
19 Thru-hull held with internal wrench (diver), nut tightened on inside.
20 Hoses and clamps fitted.
21 Boat returned to normal, sea-cock opened.


The entire process admitted one cup, possibly less of water during the process.

[Cadence]

Your idea of an expansion plug looks good. As others have said what can go wrong will.
If the seal in the through hull starts leaking make sure you bilge pump is working, it would probably just weep. What is the hose clamp below the valve?

[sy_gilana]

I just had another look at your photo.


Those ball valves come apart, without stressing the thru-hull, you can split that valve and service it. Bung the outside before you start.


Somewhere I went off course, I thought it was the Thru-Hull that needed replacing, hence my previous post. Changing a seacock is no biggie.

[TrentePieds]

I think the hose clip below the valve is a dead give away that this installation is a kluge or even a botch. Caution is called for! The OP's first post in his other thread confesses to not being an "old hand" at these sorts of things, so I can only counsel that he bite the bullet, pays what a decent valve plus through-hull will cost and pays for a short haul to do the job. The cost may be considered an insurance premium :-)

A New Zealand firm markets "Trudesign" ball valves. All nylon and exceed ABYC H-27, so they say. I have no experience with them - yet - but they sure look good on paper :-). Google them

On this job, Seasic, don't do a halffast job.

TP

[stnick]

Please take your beloved boat OUT of the water ! Install a REAL seacock one with a flange foot attatached to the hull . Not a ball valve sittinng atop a thru hull fitting ! Honest just do the right thing by your boat and yourself. ! In a couple of years just maybe that old existing thru hull fitting will rupture at the base of your ball valve and flood your boat !Please be careful . Ask a A surveyor in your area to inspect !

[Seasic]

Originally Posted by TrentePieds

I think the hose clip below the valve is a dead give away that this installation is a kluge or even a botch.

TP

The hose clamp below the valve as you see in the photo is to secure a ground wire as all the sea cocks or thru hulls are grounded this way (on this boat anyway)

I don't think it has anything to do with a botched job.


So my takeaway from all the responses is...

I am going to soak this with a penetrating spray for a few days in hopes of making it easier to remove, i will have sea cock and thread sealer on hand, if it comes loose fairly easy i will proceed and change the sea cock, if it requires more force than i feel comfortable with i will go to plan "B" and have it hauled out. If while trying to remove i do happen to break the seal on the thru hull and it weeps, i will have a plan to put a temporary seal over the thru hull from the outside and ill have it hauled out. There doesn't seem to be a tremendous amount of pressure here that would cause me to accidentally scuttle the boat before being able to apply a temporary fix in the worst case scenario.

Thank you everyone for your knowledge and expertise, my next thread will be " how do you raise a boat that sank at the dock"

[Cadence]

Originally Posted by Seasic

The hose clamp below the valve as you see in the photo is to secure a ground wire as all the sea cocks or thru hulls are grounded this way (on this boat anyway)

I don't think it has anything to do with a botched job.


So my takeaway from all the responses is...

I am going to soak this with a penetrating spray for a few days in hopes of making it easier to remove, i will have sea cock and thread sealer on hand, if it comes loose fairly easy i will proceed and change the sea cock, if it requires more force than i feel comfortable with i will go to plan "B" and have it hauled out. If while trying to remove i do happen to break the seal on the thru hull and it weeps, i will have a plan to put a temporary seal over the thru hull from the outside and ill have it hauled out. There doesn't seem to be a tremendous amount of pressure here that would cause me to accidentally scuttle the boat before being able to apply a temporary fix in the worst case scenario.

Thank you everyone for your knowledge and expertise, my next thread will be " how do you raise a boat that sank at the dock"

Sounds like you have all your $hit in one sock so hopefully we won't be seeing that thread.

[Seasic]

Just wanted to give you an update, changed the sea cock out with no problem, only mistake was taking the hose off before putting bung in... the valve was broken partially open so when i pulled the hose of it was flowing some but i was able to put a small bucket i had handy and go out and bung it pretty quick, replaced hose while i was at it, new valve has zirk fitting which will hopefully help in the future.

The newbie scores 1

[Pete7]

Looks nice a shiney. What is a "zirk" btw?

Pete

[Seasic]

[QUOTE=Pete7;2691676] What is a "zirk" btw?



Hey Pete, a zirk fitting is nipple where you can grease the valve periodically.


Roy

[stnick]

Your very lucky , and very careful . The whole deal could have gone South ! Good for you that you had fast work and good planning . !
I would not try this , but im happy it all worked out for you .