seacocks

[fishy]

This might seem a massively silly question but I would really welcome advice. Last year we bought our first boat and were told by the insurance people that before renewal the seacocks would have to be checked, serviced and if necessary overhauled.After a year all of them appear to be in excellent condition in the sense that there is absolutely no water in the bilges and they open and close easily but not too easily. My question is can their condition be more fully checked while the boat is still in the water and what would such a check involve. Also can they be given any routine service while the boat is still in the water. With thanks for any advice because the insurance stipulation on the seacocks is the only reason we are planning to take the boat out.

 

[Avocet]

Don't know from an insurance point of view what the implications are but I guess you could always ask your insurer.

There are lots of different types of seacock. Some can't be serviced (ball valves), others can be stripped and re-built like the old "Blakes" type. The best advice I ever got from a surveyor was to withdraw a sample fastener (mine are bolted through the hull) from one of them every few years to see if it had suffered any corrosion. Boy did I get a fright when I tried it! I ended up replacing all the fasteners in all the seacocks and the stern tube and the rudder bearing! Some modern boats have the fasteners glassed-in. Needless to say, I'm not a big fan of this. Incidentally, the seacocks were all fine (after thirty years in some cases) but I guess the bolts had been acting as sacrificial anodes over that time.

 

[VMALLOWS]

Tell us what type they are.

Blakes? Gate Valve? Ball Valve?

If possible the material (bronze, brass, stainless?)

 

[tome]

This can't be done with the boat in the water. Seacocks tend to be fitted below the water line and are usually Blakes (bronze with an offset hose and handle on top) as opposed to ball valves which are usually (not always) attached to skin fittings above the water-line (bronze/brass/nylon) with a handle in-line with the hose.

The Blakes type are tapered valves and have a hole in the plug. When this hole is aligned with the port (hose) water can flow. They have a compression plate with 2 bolts and lock nuts. They have to be dismantled and the tapered surfaces need to be inspected for wear and pitting. If necessary they can be lightly re-ground with grinding paste. They are then cleaned and liberally greased before being re-assembled. They are expensive to replace. I have service instructions if you need them.

Ball valves feature a sphere with a hole drilled through it. When the handle is aligned with the hose/valve water can flow through this hole. When turned at right angles, the ball prevents flow in both directions. They are prone to leakage after a few years, especially around the spindle. They are cheap to replace.

A likely Blakes failure is the toilet outlet. This is prone to bacterial pitting, usually due to them being closed before being fully pumped clear. I cannot think of a better way of securing seacoks than to glass them into the hull IMHO. The alternative is to use bolts which can easily corrode.

I know you're keen to avoid a haul out. My boat is out of the water and I've just completed a seacock/skin fitting overhaul. We have 6 seacocks and 3 skin fittings on a 1989 boat. We replaced 1 seacock, 2 skin fittings and 3 ball valves even though the survey didn't mention it. All seacocks greased, all fitted with new double jubilee clips. Whilst you're doing this fit a softwood plug of the correct size and on a length of cord onto each hose.

Best to combine this with other hull jobs like antifouling, prop maintenance, topside polishing etc.

 

[yoda]

At a guess you have at least 5 Seacocks of some sort. You do have the option of drying out if there is anywhere handy when you can do the maintenance between tides including antifouling etc. Weigh up the costs, new valves all round againts liftingin and out and winter storage. I costed up a winter ashore and decided to spent the £500 plus on the boat, it buys a lot of new valves etc. don't be aftraid of drying out alongside a wall or piles.

Yoda

 

[castaway]

If you do take the advice to change a seacock whilst along side, nothing wrong with that. Do take the precaution to be able to blank of the hole in the hull if anything goes wrong whilst you are in that most vulnerable position.

I did a seacock last Sept and had 2 pieces of ply wood with a bolt though them so I could sandwich them over the hole it there was an emergency with the job half done. ( one inside , one outside and the bolt pulling them together and plently of cheap gunge.)

I just saves you that niggling worry.

Regds Nick

<A target="_blank" HREF=http://www.yachtsite.co.uk/fairweather>http://www.yachtsite.co.uk/fairweather</A>

 

[yoda]

A fair point, I'm so used to doing things like that I always have the blankes onboard. The last valve I did had ply blanks for over a year which showes how well a single coat of paint and marine ply can last underwater. Of course if you are replaceing one for one you have a better chance of not needing the back up.

Yoda

 

[fishy]

Thanks for all the really helpful advice on this. It is much appreciated.