Seabung

nornie lees · May 05 2015, 15:43

Hi All. I have a seized seacock, which I cannot free up. Has anybody tried/used the Seabung? Its an umbrella design which is placed through the seacock, holding the sea water back, whilst you remove the seacock. Its all about cost's really, saves lift prop and splash £? Advertised in force4 catalogue £50

rgds Ray

JEN-et-ROSS · May 05 2015, 18:20

Is the 'seabung' not designed to only be used in an emergency?
The way I see it your seacock would need to be jammed 'open', but rather a lot of water would enter between whipping the hose off and inserting the thing.
OK, so far so good.
Now would come the real test. Once you've repaired/replaced the seacock. How do you screw the seacock back onto the skin fitting without having to push the Seabung out and losing it?, an awful lot of water can be expected to enter the boat.
I think I'd break the piggy bank and request a haul-out, or am I missing something obvious ?......Bill

JEN-et-ROSS · May 05 2015, 18:37

I've just watched the SeaBung Video clip on YouTube. I bet they had the boat in the slings when they did that !!, but it did work.
Though I'd still haul-out as it wouldn't go as smoothly as that if I was doing it.

Salty · May 05 2015, 18:40

You could try leaning against a sea wall or piles in an area that dries out at low water. Make sure you have good secure moorings on the shore side and that the next high water is higher than the previous and have something to stop up the hole if you are not a quick worker.

tiger79 · May 05 2015, 18:54

Why not simply wait until you next need a liftout? If it's not leaking, it's not going to be a problem.

Symphony · May 05 2015, 22:50

More than likely it is seized because of lack of use and a ring of deposits has built up around the ball. Suggest you take the pipe off (if it is seized in the closed position and fill it with penetrating oil and leave it a few days. Use a tube on the handle to give you extra leverage and you may well find that you can get it free.

The bung thing does not deal with the big problem of changing valves from the inside and that is actually undoing them from the fitting. All nice and easy when the valve and fitting are new and easily accessible as in the video, but not in most installations where you cannot get at the fitting with a suitable tool and the fitting has been stuck on for years. You end up turning the skin fitting and potentially causing a leak. The best way to replace is when on the hard and grind off the outer flange of the skin fitting so you can remove the whole assembly from the inside and replace with all new DZR fittings rather than the original brass.

BillGiles · May 05 2015, 23:37

Getting extra leverage on the handle might not be the wisest thing to do if the boat is in the water. Try explaining that to your insurer!

Symphony · May 06 2015, 09:28

The seacock is pretty robust bit of kit, but you obviously need to be a bit sensitive to the amount of pressure you apply, but the chances of breaking anything are pretty low - unless of course the fittings are completely dezincified. Never had a problem using a box spanner as a lever to effectively double the length of the handle.

Ripster · May 06 2015, 11:45

Quote from: Symphony on May 06 2015, 09:28
The seacock is pretty robust bit of kit, but you obviously need to be a bit sensitive to the amount of pressure you apply, but the chances of breaking anything are pretty low - unless of course the fittings are completely dezincified. Never had a problem using a box spanner as a lever to effectively double the length of the handle.

I have changed a few fittings and valves etc and have also used a box spanner to get a little more leverage if the valve ball is too stiff to move just with the lever. Never had an issue, but then I have never forced one beyond what I felt was reasonable for the size of the fitting. Changing the valve whilst still afloat is definitely possible (seen it done on a large MOBO once) but there is a considerable risk that the fitting seal to the hull will break away whilst attempting to unscrew the valve. Of course you can often brace the fitting from the outside, using the internal lugs to avoid this - but more difficult in the water and there is still the risk. I am with others and would urge a lift out to be safe.

nornie lees · May 06 2015, 12:35

Hi All. I believe having read your posts leave it to next winter, but hows this for a temporary solution, add a new seacock on top of the seized open seacock. All I need do is remove elbow and hose, add new seacock and replace elbow, hose. The position of the top end seacock is 100mm above sea level. The worries I have is doing nothing, as when sailing on port tack my bilges will fill with sea water coming up through toilet pan.

rgds Ray

JEN-et-ROSS · May 07 2015, 11:05

If the water enters when on a port tack maybe a 'higher' anti-siphon loop on the pipe is necessary, but in the meantime a second seacock piggybacking until winter would be a very good idea. It wouldn't cost any more as the 2nd new one would simply replace the old one.

Incidentally I replaced all our seacocks a couple of years ago ( with Forespar Marelon ones ) when the handle of one sheared off in my hand. As suggested above by Symphony, I ground the skinfittings off from the outside. In doing so I had the chance to examine the pink blotchy de-zinced cut surface of each seacock, so I wouldn't advise using undue force.