When do I replace Sea-Cocks?

[forrestmichael]

Hi, the survey on my boat recommended an overhaul of the sea-cocks for the heads. My Sea-cocks look similar to blakes but are not, they have the single leaver to close and open, one is certainly the original one fitted to my CO26 the leaver was stiff but i've moved it with a bit of force and it now moves freely. My boats out of the water so i'm not sure if they leak.

From my research it seems you need to remove the inner socket and clean it up with a grinding paste (anyone know where I get this) and fill any holes (with what). Also, the external surface of te sea-cocks is green, is this acceptable? should I clean this up as well (again with what)

Sorry for all the questions but the books I have don't really help too much. I'd much rather repair than replace with new Blakes due to the cost.

 

[michael_w]

Assuming you've got cone type seacocks.

Take them apart, clean with a bit of solvent, dab of grease and refit. No need for grinding paste unless leaking badly/wasp waisted. Normally, the bolts that keep the cone in only need to be finger tight, otherwise you can't move the handle.

 

[flyingscampi]

I think every survey says the seaocks need servicing!

I've just serviced my 1980's blakes for the first time.

If your seacocks are the same design as blakes, remove the two bolts on top and withdraw the cylinders, if they're stuck gently tap them out by putting a socket extension in the outlet pipe.

Grinding paste is a bit rough, I used the fine 3M scotchbrite pads (wire wool equivalent) to clean mine up. Mine weren't heavily scored or pitted so I didn't need to fill them.

Use a suitable grease (blakes seacock grease) for re-assembly and the bolts on top should only be finger tightened.

Don't worry about the green stuff, just wire brush it off.

 

[PCUK]

Grinding paste is available from car accessory shops.

 

[Georgio]

I have used Cylinder-head valve grinding paste, I think it was purchased from Halfords. As others have said it is only necessary if the cone is badly scored.

When putting back together use a very thick waterproof grease (like water-pump grease), I think the thin stuff sold for stern-glands squeezes out to easily.

When suitably adjusted the water stays out but you can turn the handle with one finger.

 

[forrestmichael]

ok, thanks everyone, i think i can manage that, i was worried the green stuff might mean they need replacing.

I have a feeling the inlet one might not be the cone type, it had a red handle so looks newer, is there any way of cleaning these?

 

[alan17]

Sounds as if your inlet one is a ball valve type in which case there is nothing you can do with it by way of servicing. If it moves freely and is leak free then leave alone otherwise fit a replacement.

 

[nigelmercier]

[ QUOTE ]
Hi, the survey on my boat recommended an overhaul of the sea-cocks for the heads... Also, the external surface of te sea-cocks is green, is this acceptable?

[/ QUOTE ]

I'm pretty sure a boat survey is much like a house survey, if they find something which could cause them to be sued, they mention it.

Unlike the others, I'd be a little concerned about the green. This means that the brass has been dezincified, perhaps over use of Hydrochloric Acid in the heads?

 

[VicS]

[ QUOTE ]
This means that the brass has been dezincified,

[/ QUOTE ] Sorry i don't follow the logic. Can you explain.
Dezincification of brasses is usually recognisable by a pink colouration of the surface in contact with the water due to loss of zinc, leaving the copper behind