Reconditioning Seacocks

Stemar

Stemar

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The outlet seacock on my heads seems to be leaking slightly, even though it's well greased. AFIAK, it's a pukka Blakes, with a conic insert held in by a plate with two bolts. The bolts are as tight as they can be without making the cock hard to turn.

The inlet side doesn't leak and the rubbing surfaces are nice and shiny, while the outlet surfaces are dull.

Can I grind the seacock in like I've done with engine valves? If so is valve grinding paste the right thing to use?
 
Adjusting the keep plate...

When you've reground the surfaces and greased them, I believe it's best to follow the old advice that the bolts holding the keep plate should only be finger-tight, so the handle turns quite easily. Once adjusted, use a spanner to keep the bolts from turning when you add the lock nuts. I think the theory is that if the plate is bolted down too tight, it just squeezes the grease out and leads to leaks.
 
I removed mine and ground it with coarse and then fine valve grinding paste by fitting the rotating piece in the chuck of a lathe then, with the lathe set VERY slow, moving the bit that fixes to the boat on and off it - adding the odd drop of oil to keep things moving. - Only took a few minutes. No leaks at all since then.
 
Lap er in with fine grinding paste, clean off and make sure you have continous band of contact around the top. Slap yer grease on and finger tight only with yer nuts.
Job done and tea break time. /forums/images/graemlins/grin.gif
 
Check to see if there is a ridge on the fixed taper(Near the bottom of the running face), if there is, no amount of grinding or lapping will make the taper seat, cure. Machine a rebate on the moving taper to clear the ridge and lapp in. Just a point that the previouse posts have overlooked, Hope that this is of use to you.
Pampas
 
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I'm about to do this same job on mine. What grease? must you use the pukka Blakes stuff or will waterproof stuff do?

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Not often that the expensive pukka stuff is worth it, but it is in the case of blakes grease. It sticks like the proverbial to a blanket. I suspect it is a close relative of the stuff we used to put on the kids bums to stop nappy rash.
 
Thanks all

I don't think I'll use the lathe though. 2 reasons, though the second pales into insignificance beside the first:

1. The seacocks have been in since 1970. I suspect getting them out, ground in and refitted ain't going to happen between tides.

2. I haven't got a lathe. /forums/images/graemlins/wink.gif

Still, if I can figure out a way to attach my cordless drill, I might try that. Any ideas anyone?
 
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