Seacock with Leaky Valve - Plug from Outside ?

[enovillo]

Last night, as I was closing the galley drain seacock, I noticed that when the handle is half way between open and closed there's a leak through the nut holding the valve in place. The nut is cracked, but doesn't leak when the valve is open or closed, only when it's half way.

Leaving the "how did this happen?" discussion for some other time, I'm now focusing on fixing the issue before it becomes a more serious problem.

I'm thinking that I could plug the seacock with a wooden peg (or something more rubbery that would block the hole better) from outside. That would allow me to change the valve without hauling the boat.

Does that make sense? Has anyone tried it? Or should I just spend the money to use the travelift for 20 minutes?

[Therapy]

I have changed the body of a valve while in the water.

Plug the hole, have everything ready and laid out to do the job quickly. Not necessary in my case but not to be ready would be foolish.

[capt_douglas]

Plug the hole. You can get damage control plugs at most marine stores. They're soft wood (probably pine) that you insert until tight and the wood swells from the moisture and seals well. You may have to cut the plug down some as they seem to be a bit long for most of my uses. You can also use a rag or damage control mat. It's a bit tense when you start undoing the bad valve but if you prepare, you'll get a bit of water and the satisfaction of doing a job right.

I'd make sure you had the replacement valve on hand before you start and have the bilge pumps ready. You might also have a second plug in case the first one doesn't work.

[enovillo]

Thanks a lot guys. It looks like I wasn't too far off the mark with my amateurish plan.

However, there's one thing I'm not quite getting: should I plug it from inside or outside?

A plug from outside the hull is intuitively more appropriate for me because the water pressure is going to help the plug stay in place. But the way you've worded your answers it sounds like you've applied the plug from inside?

[Therapy]

From the outside.

[osirissail]

I use kitchen or bathroom sink stoppers sized to the thru-hull. Tie a little string onto the ring and then insert the stopper from the outside. When the job is finished just pull the little string to remove the stopper.
- - If a leak develops while you have the seacock removed the temporary solution if to smash your thumb with the bronze seacock and stick your thumb into the "hole in the dike," Being Dutch helps. But seriously just have rags or a piece of pvc hose the same O.D. as the I.D. of the thru-hull and screw a pipe plug into one end. That is the "safety" plug should the outside plug let loose for any reason. I am not a big fan of pounding wooden cones into the thru-hull as you may warp or deform the thru-hull and not be able to get a seacock to fit back onto it.

[ConradG]

Plumber's test plugs. They are like the one hole stoppers from science class with a wing nut and plate that expands the stopper. Buy a few extra while your there and lanyard them to each through hull for the "in the event of" scenario.

Also saw a nifty spongy rubber thing by forespar for plugging but it would be too big for this ap. Sort of like those earplugs that you squish and they expand...

[GordMay]

Originally Posted by ConradG

Plumber's test plugs. They are like the one hole stoppers from science class with a wing nut and plate that expands the stopper ...

Plumbing Test Plugs & Balloons

➥ http://webstore.petersenresources.co...ble_plugs.aspx

➥ http://www.plumbingsupply.com/testing.html

Has anyone seen/used the "TruPlug", a tapered circular cone shaped plug, made of a proprietary foam?
It’s compressed by hand, and inserted into the hole stopping, or reducing the inward flow of water as the foam returns to its original shape.

TruPlug (division of Artelier Studio Llc) ➥ http://www.truplug.com/

[ConradG]

That's the one I saw! A big squishy earplug Forespar has a vidio of it working on their site...a first hand account would be nice.

And thanks Gord, those are the test plugs...Plumber's supplys and good hardware stores carry them.

[barnakiel]

Positive. Can be done if properly plugged from the outside.

b.