Replacing seacocks

[ghostlymoron]

The seacock on one of my cockpit drains has a problem. The handle turns but the ball doesn't. I have a spare and am now on my drying mooring so I could change it between tides. How can I replace the ballvalve without disturbing the skin fitting? My concern is that I will replace the seacock but create a leak between skin fitting and hull which will only be apparent when the tide comes back in.

 

[Skysail]

You are right to be concerned, it is easy to break the seal on the hull. Usually the skin fitting will have 2 lugs inside the hole, you need to get a purchase on them to stop the fitting turning. There is a special tool for the job called a step wrench, but you might be able to improvise one with a piece of hardwood.

see http://www.diybob.com/diySeacock.htm

 

[VicS]

If you are going to do it between tides be sure to have a wooden bung handy just in case things go wrong and the tide does not feel like waiting for you to finish.

I would not bank on doing it without disturbing the skin fitting.
Be prepared to renew both.

 

[gandy]

We replaced two a couple of years ago, and the skin fittings stayed put. I wouldn't like to have banked on it though.

 

[Gunfleet]

I favour having the boat in a field before you do this.

 

[TradewindSailor]

Even if you break the seal on the through hull, you shouldn't get much water in, well within the capacity of you bilge pumps. You could then reset it in the next tide if tightening the seacock nut doesn't work.

 

[davel]

I replaced one a couple of weeks ago for the same reason (handle turns, ball jammed). The whole arrangement of thru-hull, seacock and pipe stub was seized together and proved impossible to free. I ended up having to grind off the mushroom cap on the thru-hull. All in all this took about 4 hours and needed access to an electricity supply (actually via a generator). I'd not want to do it on a tidal mooring unless I felt confident it was all going to go smoothly or I had a plan B !

 

[oldsaltoz]

length of flat bar or tyre lever with a big shifter will help hold the fitting in place, if possible hold both the inner and outer fitting yourself rather one person inside and one out, you will get a feel for the balance of pressure required.

 

[higler]

Had a similar experience not long ago, I did it but a bit awkward. If the thread in between the hull and fitting is long enough its possible to put a stillson on the thread to hold it then unscrew the fitting. It can damage the thread but being bronze it wont fail the nut should you wish to remove it at a later date. It may be an idea if your on a drying mooring to run your boat on a hard beach or whatever at high water then you should have plenty of time to do it properly?

 

[saltwater_gypsy]

Just another pennyworth.
Heating the old ball cock with a hot air gun will soften any sealant which may have been put on the thread.

 

[vyv_cox]

A little gem for removing seized skin fittings, originally posted by Skipper Stu. Tap a pice of wood into the skin fitting bore. Use a hole cutter the same size as the through-hull part of the skin fitting to cut off the flange, with the piece of wood to take the pilot drill. It takes about five minutes to get through the flange, when it and the seacock can be removed. A decent battery drill will do it comfortably: mine is an Aldi special costing £37, it will do a dozen of these jobs.

I would plan on replacing skin fitting and seacock, if they unscrew easily keep the skin fitting for a spare. Rebed the new one and fit the seacock. You should easily be able to do this in a tide.

 

[JordanBoon]

I replaced one a couple of weeks ago for the same reason (handle turns, ball jammed). The whole arrangement of thru-hull, seacock and pipe stub was seized together and proved impossible to free. I ended up having to grind off the mushroom cap on the thru-hull. All in all this took about 4 hours and needed access to an electricity supply (actually via a generator). I'd not want to do it on a tidal mooring unless I felt confident it was all going to go smoothly or I had a plan B !

Is there anyway i can chage my seacock without leaning the boat against something, taking it out the water. I have a 27ft Dufour with a 6ft Fin keel, my sea cock for toilet water output is either jammed or broken, eitherway it needs replacing.

any info would be great

 

[Tranona]

Short answer is probably no. It is probably seized because of build up of deposits because it has not been operated regularly. Very difficult to unstick as the deposits tend to be on the seaward side.

Easiest way to replace is as described above. Grind off the outer flange of the skin fitting and fit a new bronze skin fitting and DZR valve and hose tail. Worth replacing the hose as well when you have it all apart. Obviously boat has to be out of the water to do this.

 

[pvb]

I recently replaced the through-hull and seacock on the heads outlet. In the absence of a proper step wrench to hold the through-hull, I raided my socket set for a big socket which just fitted in the hole in the through-hull, then used an angle grinder to make two little slots in the rim of the socket which fitted the little ears inside the bronze through-hull. This worked a treat.

 

[philwebb]

Seacocks

I replaced mine today. They were stuck, but when heated up with a blowlamp they gave up easily. As suggested by a previous poster, held threaded bit with large pump pliers and turned seacock with very large adjustable spanner. Did this on a scrub berth between tides.

 

[wotayottie]

Why not do the skin fitting at the same time? Wont takemuch longer and willmake sure everything is OK

 

[steveallan]

Assuming the valve is stuck in the open position, is it possible to fit the new one on top of it? You could then replace if / when you lift out for the winter.

 

[youen]

through hull fittings

How long does a through hull fitting last.When do you know is time to change them and the seacocks.What is said by the surveyors and insurances.Thanks

 

[vyv_cox]

How long does a through hull fitting last.When do you know is time to change them and the seacocks.What is said by the surveyors and insurances.Thanks

It's not wise to generalise too much as there are certain factors that can accelerate corrosion considerably, like hull material, shore-power problems, misguided attempts to link them all electrically, and others. However, I know of plenty in the 40 year region, still working fine. Mine are all 25 years old, including a ball valve that might be expected to fail in fairly short order.

There was a thread here not long ago that described a surveyor's suggestion that 10 years was the limit. AFAIR nobody agreed with him. It's easy to see whether fittings are stil in good condition, so a time-based replacement seems totally unnecessary.

 

[Tranona]

Agree that there is no typical life. Two of my original 1963 cone type seacocks are still perfect - the third was replaced because the cone wore oval but was otherwise sound. Have just replaced an ordinary DZR ball valve after 17 years - still working perfectly, but was too small for my new engine.

Replaced one in a grp boat after only 8 years because it was seized and the spindle weeped. Main problem with ball valves is seizing through lack of use and the mild steel handle rusting. Keep them clean and dry (not always easy) and operated regularly and they should have indefinite life.