Sticking sea cocks

rafiki_

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Any thoughts on how to free off sea cocks without lifting the boat? Both engine cocks are very heavy to open, and it think the gennie sea cock is stuck open.
 
What type of seacocks? If they are brass, bronze or stainless ball valves a bit of very hot water poured over the outside of them to expand the metal a little may enable you to free them. After that just work them back and forth until they remain free, then do not forget that regular opening and closing is the best way to stop them seizing up.
EDIT: A gas torch is the last resort as many ball valves have plastic seals in them. I would not recommend trying one.
 
Almost certainly a build up of deposits around the edge of the ball and the barrel. Stiff, but movable ones might benefit from some hot water poured down them when closed then opened and closed to free them. Stuck open more difficult because the deposits will be downstream on the seawater side and best cleared by bunging up the outlet and filling with hot water from the inside. Penetrating oil may also help clear the deposits.

Solution is to operate the valves regularly to prevent build up.
 
Another thing is that the handle may be too tight. There is a slim locknut on all of ours (only 5mm wide, and 17/32" AF) which can be too close to the body of the sea cock.
 
For completeness, the 2 engine cocks feel ok now. The gennie cock is stuck. I am reluctant to get the lump hammer on it, and will probably sort at the next lift.
Many thanks for your suggestions.
 
Rafiki I carry a bag of assorted steel tubes, straight and bent, to extend the length of the handles. I'm not recommending overdoing this by attaching a 1 metre long extension or anything daft, but I find that with seacocks in recesses or under machinery your angle of attack means you cannot apply the full strength of your arm, and in that case extending the handle helps. Example here http://www.ebay.co.uk/itm/1-1-4-32m...arts_Vehicles_CarParts_SM&hash=item20b6800b3e
 
Personally I'd leave until out the water if the hot water suggestion doesn't work. You don't want to risk breaking the hull fitting especially as it could be weakened already due to any number of reasons. Make sure hose is secure with two jubilee clips and carry a bung ! Also make sure bilge pumps work and are located in the right area.
 
Rafiki I carry a bag of assorted steel tubes, straight and bent, to extend the length of the handles. I'm not recommending overdoing this by attaching a 1 metre long extension or anything daft, but I find that with seacocks in recesses or under machinery your angle of attack means you cannot apply the full strength of your arm, and in that case extending the handle helps. Example here http://www.ebay.co.uk/itm/1-1-4-32m...arts_Vehicles_CarParts_SM&hash=item20b6800b3e

Good spot JFM, the gennie lever is not so easy to access, and will look at this as a solution. Will measure up the lever for an extension. I did try a socket, but could not find sufficient access. Main engine cocks not too bad, as I can get a shoe to them when needed.
 
The solution depends on the type of cock. Blakes type need stripping, degreasing and re-greasing. Ball valves can't really be maintained except by exercising regularly. Gate valves should all be replaced.
Any thoughts on how to free off sea cocks without lifting the boat? Both engine cocks are very heavy to open, and it think the gennie sea cock is stuck open.
 
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