Blanking old seacock

[Rivers & creeks]

This winter we re-routed the forward sink drain and don't have time before launch to remove the old blakes through hull fitting. We can close off the valve and plug the hose that's on it but for a belt and braces before we come out of the water again next September, is there a way of plugging it from the outside?

 

[sailorman]

can you get a compression blanking cap from a plumbers merchant

 

[Rivers & creeks]

Maybe but I don't know what one of those is!

 

[Tranona]

Remove it completely and fill the holes. However it is safe to leave it there (closed of course), perhaps with a short length of hose with a bung in it.

 

[Poignard]

I have been sailing around for years with a redundant Blakes seacock that has nothing connected to it. Just move the lever to the shut position and then tighten down the clamp plate screws so that it can't be accidentally knocked open.

 

[prv]

Just move the lever to the shut position and then tighten down the clamp plate screws so that it can't be accidentally knocked open.

You could take the handle off too.

If it's anything like mine, a couple of months without movement and it'll be corroded in place anyway

Pete

 

[nigelmercier]

I've also got a through-hull I want to block off, are there any secure ways to do it without a sea cock?

 

[Tranona]

You might find a blanking plug that screws onto the though hull. The only secure way is to remove the fitting completely and glass over the hole. Glass over the inside, cut a blanking plug that fits the hole from the outside. Epoxy into place and make good the outside. If it is above the waterline you will need to gelcoat the repair to blend in, but below the waterline just epoxy, prime and antifoul.

 

[sailorman]

Maybe but I don't know what one of those is!

http://www.wickes.co.uk/invt/420243/?source=123_75

 

[prv]

http://www.wickes.co.uk/invt/420243/?source=123_75

Not a lot of use for sealing a Blakes seacock though.

Pete

 

[nigelmercier]

You might find a blanking plug that screws onto the though hull. The only secure way is to remove the fitting completely and glass over the hole. Glass over the inside, cut a blanking plug that fits the hole from the outside. Epoxy into place and make good the outside. If it is above the waterline you will need to gelcoat the repair to blend in, but below the waterline just epoxy, prime and antifoul.

I guess a DZR blanking plug would work.

I'm a bit concerned about the blanking plug idea, I wonder if there is a way to cut a stepped or tapered plug and hole.

 

[Tranona]

That is also brass, so not sure I would rely on that underwater.

 

[sailorman]

It is not actually "under water" is it.
it is there purely to stop the ingress of water, in case of an accidental operation of the lever. also more secure that your cockpit drain hose.
i have one on a redundant Elanco seacock

 

[Deleted member 36384]

Use a short length of hose, say 4" long attached to the sea cock hose tail. Fill with grease, insert wood plug and clamp with double hose clamps. The grease just acts to prevent ant water getting in while blanked off. The sea cock is of course closed. I have an old generator cooling water inlet Blakes sea cock isolated like this. This way you have a double barrier to the sea.

 

[nigelmercier]

http://www.wickes.co.uk/invt/420243/?source=123_75

That is also brass, so not sure I would rely on that underwater.

It is also a compression fitting! The correct part looks like this:

They normally have a rubber insert, but I guess it could be fixed with epoxy.

 

[Tranona]

I guess a DZR blanking plug would work.

I'm a bit concerned about the blanking plug idea, I wonder if there is a way to cut a stepped or tapered plug and hole.

The plug is only to fill the hole. The watertight integrity is achieved by glassing over inside. You could just laminate glass cloth circles into the hole as they will bond to your internal laminations. However a plug cut from ply then soaked in epoxy or lay up a flat square of GRP and cut a round plug is neater and easier. Another way is to make up a pad for inside with a disc attached to it the same size as the hole and laminate that to the hull inside.

 

[prv]

It is also a compression fitting!

It's a compression fitting because it's a response to a different question

Sailorman originally suggested a compression fitting in post number two. Not a very useful suggestion, as most underwater plumbing does not involve the kind of copper tube that compression fittings clamp onto, but it's in response to that suggestion that Lazy Kipper asked what a compression fitting was and Sailorman answered by posting the picture.

The discussion about a screw-on blanking plug for your orphaned skin fitting was entirely separate

For what it's worth, until I got around to plumbing in the hoses all my seacocks (except the cockpit drain) had a male BSP blanking plug screwed into them, with PTFE tape.

Pete

 

[sailorman]

This winter we re-routed the forward sink drain and don't have time before launch to remove the old blakes through hull fitting. We can close off the valve and plug the hose that's on it but for a belt and braces before we come out of the water again next September, is there a way of plugging it from the outside?

It's a compression fitting because it's a response to a different question

Sailorman originally suggested a compression fitting in post number two. Not a very useful suggestion, as most underwater plumbing does not involve the kind of copper tube that compression fittings clamp onto, but it's in response to that suggestion that Lazy Kipper asked what a compression fitting was and Sailorman answered by posting the picture.

The discussion about a screw-on blanking plug for your orphaned skin fitting was entirely separate

For what it's worth, until I got around to plumbing in the hoses all my seacocks (except the cockpit drain) had a male BSP blanking plug screwed into them, with PTFE tape.

Pete

I gave him an answer based on his question.
i have an "Elanco" skin fitting blanked off with a compression blanking cap

 

[Tranona]

However your answer is not a lot of use for Lazy Kipper as he has a Blakes seacock. So the only way your compression fitting would work is to have a plastic tube on the spigot with a copper tube inside it and then the compression blanking plug. Seems a lot of redundancy when the seacock can be made watertight in the way suggested by others.

 

[Boo2]

You might find a blanking plug that screws onto the though hull.

http://www.wickes.co.uk/invt/420243/?source=123_75

Don't think that will work with the OP's Blakes seacock ?

Aiui, the preferred method is to file or grind out the hull inside and out with a 12:1 conical taper (ie width is 12 times the GF thickness) then lay up GF inside and out so the plug formed is self-bonded and cannot fall out even if it does not stick to the hull's older layup. Process is described in the West Systems book which is a free download on their website.

I would not use a wooden plug in the hole left by the seacock because I'd be scared of unseen rot eventually finding its way through.

Boo2