Stuck seacock

[Iliade]

Couple of comments:

Suggestion of applying heat won't work particularly well whilst the boat is in the water.

Likewise I can't see how you might introduce something to dissolve the crud jamming it, which is most likely on the seaward side, whilst still afloat.

So you're left with the various purely mechanical options. Love to know what eventually works for you. I have similar ball valves, not jammed as yet...

You'd be surprised at how well you can locally heat these things, despite the water inside.

You have to plug the outlet from the outside and wait for passive dispersion, this involves getting wet. On some boats just an arm, on others it is a full-body experience, unless you dry out against a wall.

One of the worst jobs I have had to do was rodding the things from the outside after significant pressure had been built up against the obstruction...

 

[Graham_Wright]

Due to the "propeller coming adrift" adventure on our last week long cruise, I've not been to visit Mirage as much as I'd like as she is a couple of hours away. On my last visit, I worked all the seacocks.... apart from the aft heads outlet that appears to be stuck!

It has always been a bit tight (when I purchased the boat I was concerned, as this head had been used for storage, it was truly stuck, but with some persuasion it came free), and this just happens to be the only seacock and skinfitting that has been changed by the previous owner (it's on the boat "todo" list to replace all skin fittings).

It looks to be of good quality, and dezincification resistant (I read the DR there)

Previously when its been a bit jammed, I have tugged it a bit harder, and it would free up... I feel this time I would need to apply extra leverage to get it to move. Is this a great idea? Or wait for lift out and inject some rydlymn up it and then replace with the rest.

Edit: It appears to be one these:
Aquafax Isis DZR Brass Ball Valve - Fox's Chandlery (what documents I can find here:
https://www.specifiedby.com/relianc...s-with-t-handle_specifications_1_b84903c6.pdf)

Do what my wife does - use a bigger hammer.
I did, and the whole thing came adrift. That was when I discovered that a plastic tomato sauce bottle makes an ideal bung.