How to free up seacocks?

[JesseLoynes]

Hi,
Wondering if anyone knows any good techniques for freeing up the seacocks on our yacht?
We bought our fab little 6 tonner a few months ago, and I've been working through the odd problem and repair as we go, but I'm now a little stuck with the seacocks.
we have a baby blake in the bows, with two seacocks; for in and out.
Both are shut, and have been that way, I believe, for 3 years!
Now having removed the odd through-fitting when replacing planks over the years on other boats, I know that over time the bolts can become quite brittle and the planking quite soft.
Ruthie is currently on a mud berth, afloat for about 6 hrs of each tide, so I'm being very careful when it comes to applying leverage to open the seacocks.
Does anyone have any experience or good tips for freeing seacocks from inside the hull, without doing any damage?

Any ideas or tips would be fab.
Plus it would greatly extend our cruising capability for the bank holiday! /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

 

[tobble]

IT may not work on something that's been seized that long, but apply heat to the body of the seacock, probably with a heat gun, or gently with a blow torch - the body gets hot and expands before the cone does. This worked when I stupidly over tightened my blakes seacock, but that was imediately after I did it, and about 10 mins before it was due to be lifted back in the water!

if not, spray on the proprietry penetrating Lubricant, leave for some hours and try to tap it out from below using a hardwood drift. I say tap, I was hitting mine as hard as I could with the small area to swing in, and it didn't do any damage to anything. of course that's if you're either out of the water or have gills...

from inside the hull, you could support the body with molegrips for example to allow you to apply more wiggle.

p.s. I assumed you were talking about the cone type blakes seacocks rather than ball or gate valves.

p.p.s I successfully re-bedded my sea cock using a coarse polishing compound (Farclea rapid I think, or may have been the finer G3) instead of the actual bedding compound...

 

[captainslarty]

Ullo Capt´n , Nice boat !
Best thing really is to replace them.
I realise the time constraints ´tween tides, so heres how I do it.
Get yerself a hole cutter, not the B&Q ones, the real McCoy metal solid cutters with attachment.
Hammer a wodden plug into the hole, from outside... Chissel the plug off level, then use the hole cutter to remove the flange, cutter is a tad bigger than than through fitting, or, a tad smaller than the flange if you see wot I mean.......

Anyways, prior to all this, prepare new through hulls, new seacocks etc, bit of sikoflex, and do the whole thing in one, best to replace everything in one. sleep happy, happy is good, good is better, and better is restful.
Trying to remove the old seacock from the throughull can be stressfull tween tides, and no guarantee, so out wit´old, in wit´new.. so to speak.

ps. use sika on the threads, dont use thread sealer or ptfe...
Joe.

 

[rjp]

I had the same problem as you, though my boat was ashore at the time. I took the whole lot out to the bench where I clamped the body of the seacock in a vice and using a large adjustable spanner on the square end (after removing the handle) found it shifted quite easily. It was just held by caked up grease really and was in good condition despite being over 30 years old. (This was after I had broken the handle trying to shift the thing in situ using a lever on the handle!!)

Lap it in with a bit of valve grinding paste, clean thoroughly and reassemble with a smear of waterproof grease and will probably be as good as new. It shouldn't be necessary to replace in my opinion unless very badly pitted or there are signs of dezincification when it will be a definite pink colour. These things are made out of DZR which is pretty resistant.

John

 

[Krusty]

A liberal application of ACF (Anti-Corrosion Formula) and a few days patience, then gentle tapping might do the trick. I have found it highly penetrating and very effectice on alloy and bronze parts, including winches.
It is used a lot on aircraft and motor-cycles: You might find ASAP Supplies have it: (Google).