Blakes Sea Cocks

G

Gwylan

Well-Known Member
Joined
31 May 2007
Messages
3,651
Location
Moved ashore
Visit site
Anyone got a tired and tested method for getting these things 'free'. Just back from a painful and fruitless day trying to get both the heads sea cocks free.
There has been WD40, the blow lamp - with near disastrous results we will not try that again too soon. Then there was the brute force solution with escalating hammer sizes.
Now I know they are jammed open so I cannot just put it all together and hope for another season - also they should be almost indestructible, if I can get the corrosion free.
Constructive and practical suggestions for a very confined space are more than welcome.
 
They have probably seized because they have not been greased and you may have tightened the locking plates too much. You could try a drift up from outside. They are tapered cones so once they shift they will come straight out. However, I would be tempted to take them out of the boat, overhaul them properly and refit with new bolts. Will cost a bit but they should last a long time, particularly if you use the proper grease and strip them down each winter.
 
Thank you.
Seems too obvious now I look at the drawings and think about how these sea cocks actually work.
Large hammer, hefty dowel are in the truck first thing in the morning
 
Yep, well the previous owner was a bit too quick and I was too slow to catch that one.
First time I've looked at them, days before going back in the water.
They are glassed into the hull quite firmly - well it seems firm even after this afternoon's session with the largest hammer in the box. So removing the entire assembly could be a bit of a pain - hence the urge to give them a good servicing.
So, it's hammer and dowel and then give them a good cleaning - what's good for getting 20 years of neglect off them?
But we will prevail
 
Just remember to tie the handle on to the hose or the main part of the body, otherwise when it finally lets go, it'll go shooting across the boat and make a dent in whatever's in the way.

I didn't once, and it went through a scuttle. /forums/images/graemlins/frown.gif

Luckily, it was open. /forums/images/graemlins/smile.gif

Made a hell of a bang when it hit the corrogated iron of the shed!
 
Make that a metal drift- wood too springy and lump hammer. Richard, Northshore yard manager showed me that one- I'd done one, needed it out again to lap the 'closed' face and couldn't get it out. I struggled with dowel and someone pulling from inside, winced when he hit it hard, but it worked!
 
As said, re-lap in situ with grinding paste............. doesn't have to be a polished finish.

When you re-assemble use a waterproof grease, doesn't have to be Blakes. I use Finish Line Teflon based grease which is for bicycle chains. Marinestore also do waterproof grease by Aquaslip and Starbrite.

The secret is not to overtighten when you put it back together, you can move my seacocks with one finger. The grease is the seal not a metal-to-metal contact.
 
Also get in to a routeen of cloasing them everytime you leave the boat. Even the cockpit drasins need to be closed and re-opend. If you do not only will it stop them seasing up but mean you know they are working - it's too late to find them seased when a perished hose has failed!
 
Quote "Even the cockpit drains need to be closed and re-opened. "

Umm, suppose it rains heavily whilst you are away from the boat for an extended period....

I wouldn't want to come back and step into a cockpit even half full of water. Mine stay open (but the valve is moved regularly)
 
I was told by my surveyor (so I can't actually vouch for it) that should the boat sink at it's mooring with cockpit drain seacocks open then underwriters would be unlikely to pay out in full, as they would expect a boat to have been left with all through-hulls firmly shut.

Equally they wouldn't pay out for water damage due to rainwater overflowing the cockpit and entering the accomodation, as obviously they would expect some means of emptying/draining the cockpit to be in place /forums/images/graemlins/ooo.gif

Ho hum.
 
Sheff,
The 'closed' faces of our two heads ones are still quite scored.
i think they were closed for a long time afloat at some time and/or lost anode cover.

Is it worth lapping them really smooth, they work ok, and I suppose there is then the risk of seepage round the edges of the depressed face?

What think?
 
[ QUOTE ]
that should the boat sink at it's mooring with cockpit drain seacocks open then underwriters would be unlikely to pay out in full

[/ QUOTE ]

My insurance policy states that all sea cocks should be closed when the boat is left except for the cockpit drains which should be left open.
 
If they are not operated regularly, there is a danger that the cones go slightly oval to the extent that they won't bed down and may leak even if greased. This happened to my toilet outlet last year - it was actually a Rowe seacock, but same design as a Blake. It had become stiff so I backed off the plate a touch, operated it a few times, but made the mistake of leaving it open. The little weep was enough to fill the boat nearly to the bunk tops in just over a week. What a mess!

Ovality is obvious when you try to lap it in with paste as you get an area of cone where the paste is untouched. Took a deep breath, coughed up the £125, remade the hole and have a new Blakes which will hopefully last at least as long as the Rowe (43 years). The other two Rowes still work perfectly.
 
I was feeling really encouraged that I cold crack this one - now I have met the issue of ovality. Also the usual problem with these jobs that you never know how good the job is until she is back in the water and you are racing around checking all the sea cocks where water might enter.
Thanks anyway
 
Hope I haven't frightened you too much! Ovality will become obvious when you use the grinding paste. Clean all the crud out of the body, lap in with the paste, clean again with paraffin and re-assemble with plenty of grease. If they turn smoothly with no tight spots they should be OK.

Bit concerned if they are actually glassed in. They should be through bolted with a plate on the outside and a pad (which may be glassed in) on the inside. It is much easier to service them outside the boat (no grovelling in the bilges) and it gives you a chance to check the bolts and replace if necessary.
 
[ QUOTE ]
mm, suppose it rains heavily whilst you are away from the boat for an extended period....


[/ QUOTE ]

You could leave them just cracked open. That will allow rain to drain away but if, say, a hose came adrift, the boat would fill up very slowly and, with reasonable luck and decent neighbours, someone will notice when she is below her marks and give you a timely phone call.

[Personally I leave mine wide open, but operate them every now and then check them. I have good quality hoses and two Jubilee clips on each end so I don't see what can go wrong]
 
Well that was an epic day. Big hammer, suitable drift and the thing popped out after one serious, boat moving belt. The smaller one gave up with a whimper. Seemed to get the message that we meant business
Ground them in and it all seems to be just fine - relaunch day will show the true quality of our labours.
Having replaced or serviced all the sea cocks on the boat we could have a tense time after relaunch
 
Hi Gwylan did you use a metal drift? I've got a seized seacock to and I've been thumping at it from below with a sawn off broom handle and it hasn't moved at all. I was worried that a steel drift would crack the brass valve.
 
You must log in or register to reply here.

Share this page

Top