Thru hull ball valve doesn’t shut off water

[skipgundlach]

Originally Posted by HopCar

Engine raw water pumps are all self priming. If his isn’t self priming he needs to fix the pump. I like to mount my strainer just above the waterline so I don’t have to shut the seacock to clean it.

That said, I have seen generators run with electric pumps that weren’t self priming but they didn’t come from the factory that way.

As you saw, it's an electric pump, probably March.

But for most propulsion engines I expect you'd find they use impeller pumps.

Some PO had moved our filter from its factory mount location (based on the holes we discovered behind the wooden mounting plate when I went to change it) and it was as another suggested, well above the water line.

Ours is not fully submerged, but I can open it and have the water level reach the top of the filter at rest. That happened when I moved the mounting assembly back to the factory level

Sorry to sidetrack, as this isn't really the subject of the thread...

[sail sfbay]

Originally Posted by marcjsmith

......... I' ve got a mag drive pump on my ancient lunaire a/c that's not self priming and everything needs to mounted below the W/L to the pump won't lose its prime..........

Off topic but I will address this issue......replace AC raw water pump with a self priming pump OR follow the recommendations in this thread to prime it:

https://forums.sailboatowners.com/th...c-pump.173414/

[Cheechako]

Near the ball is the thinnest and weakest part of the structure. Your ball is probably broken off. It's the down side to ball valves, by design.

[sail sfbay]

Originally Posted by Nani Kai

..........Anyone else ever experience this? Any bright ideas to resolve it? As long as the strainer cover stays on there’s no water ingress. All the hoses to and from the thru hull, the pump and the strainer were replaced April of last year........

Stating the obvious........I assume you double clamped the hose connections.

[CarinaPDX]

I think this is being over-analyzed. Buy a new ball valve. Back off the existing ball valve, short of coming off, then put a turn .or two of teflon tape on the thru-hull threads. Then remove the old valve and slap the new one (ball open) on the thru-hull, thread a couple of turns then close the valve, and finally tighten down the valve. It's a bit messy but it works.

Yes, this sort of thing happens. My 3/4" valve for the engine intake did exactly the same thing (and we are talking about an American valve, not European). I replaced it as described in January in Gõteborg, Sweden. The water that sprayed out was very cold, but over quickly. There is no need to dive over and plug the outside, although having a softwood plug available, with a mallet, on the inside is a good idea.

Long term the best approach is to convert to Groco flanges, as recommended earlier. That wouldn't change either this problem or this solution but is a better way to go. By all means use quality valves and make sure the threads match (taper to taper, straight to straight).

Just do it and get on with things.

Greg

[Clivevon]

Originally Posted by BillKny

Typically the “ball” has a notch, and the end of the shaft has a key that fits in the notch. One, or both, are broken. No easy fix. This is almost surely one of the cheap brass ball valves that so many European boat builders have gone to. The regulations in the EU require them to be suitable for use for at least five years, you are ahead of the game….

I would suggest you replace all the factory installed valves with proper bronze or Marelon sea cocks.

The logistics of that… I can’t help with!

+1 I would agree with that. I like TruDesign valves.

[Mike Banks]

I have used a fothering buckle on occasions. Depending on where the outlet is, this might work for you.

The "Buckle" is a piece of plywood which is flexible in one direction, I use 3 or 4 mm plywood saturated with epoxy and having lateral stiffeners of about one inch by one and one half inches to make it flexible only in one direction around the hull side over any leak. To hold it in place, a belt such as a ratchet strap or even a rope with a truckie's hitch can be used to hold the buckle against the hull. The plywood smooth side that will face the hull has rubber seal glued all around the edges, so that water pressure and the belt used will hold it firmly against the hull. Your leak is then "Fothered."

Put this buckle over your through hull and tighten it down against the hull. Sometimes you will need more than one strap. so make provision for one each end as well as a slot for one in the middle. I keep several of these patches of different sizes aboard--one never knows when a large object or a reef outcrop could damage a hull--and lets face it--nothing else is going to work that you can rig comparatively quickly.

This is nothing new, it is an old sailing ship trick. One that salvage crews use a lot when recovering a damaged vessel. In their case they use self-drilling screws to screw the buckle over the damaged hull before pumping it out.

Once the buckle is secured, you can go below decks and take out the sea cock valve. You may get a small water flow, the seals may not be perfect--but you will be able to put on the new valve before your vessel, like the sun, sinks slowly in the west.

[stormalong]

DON'T PANIC.

As long as there is no other problem you can just leave it open until your next haul out. If you are truly worried about some other failure sinking your boat do as follows:

Ball up a plastic shopping bag, remove the hose (yes there will be water coming in) push the plastic bag through the valve into the though hull to stem the flow.

Add a second valve above the bad one with a short piece of hose and hose barbs on the new valve.

Send a diver down to capture the plastic bag ball as you push it through with a long rod or dowel.

Now you have a way to close off the water flow without putting any stress on the existing fittings.

On the next haul out replace the through hull and valve. I too am a big fan of plastic fittings - no electrolysis issues. Some of the Marelon seacocks on my boat are original - 35 years old and working fine.

[deblen]

Thread drift warning


https://www.admiralyacht.com/wp-cont...at-sinking.pdf

[LittleWing77]

Originally Posted by Manateeman

There is a Marine how-to article on this but I don’t know how to post...maybe some cruiser can help.

Here you go, Manateeman (and Nani Kai):

Replacing Thruhulls and Seacocks
https://marinehowto.com/replacing-th...-and-seacocks/

Warmly,
LittleWing77

[anchorbend]

I saw a video on this little device which may be a solution if you are nervous about removing the ball valve. Hopefully they are still available.

SEA STOPPER

[skipgundlach]

Originally Posted by anchorbend

I saw a video on this little device which may be a solution if you are nervous about removing the ball valve. Hopefully they are still available.

SEA STOPPER

Very nice.

It doesn't address the potential torque issues, but if there is enough thread protruding above the nut and below the valve, you might be able to get a pipe wrench on it to minimize torque loosening...

[Uncle Bob]

Hi, I have done the wooden bung in the through hull number and it worked very well for me, no catestrophic failures and the new valve has not leaked, it's been years.

[chriswheat]

If you want to do a short haul to replace thru hulls there's a yard that I think can haul it close to you (up the Altamaha River). i forget the name of the yard but if you google Two Way Fish Camp and call them they will know. The yard is on the same property. I know I saw some cats in the yard when I was there for 6 weeks last year waiting for an injury to heal, very nice bunch of folks there. Mind the tide if you head up the river, it runs 3-4 knots on the ebb.

[Nani Kai]

Thank you all for your thoughtful and informative responses. I will respond as time allows to individual posts. I have decided to leave well enough alone at this point as there is no water coming into the vessel. I will want to replace other thru hulls I’m sure as they are the same age as well as refresh bottom paint so will do everything in November when we return in prep for cruising season. I appreciate the info about the St. Mary’s haul out option. I will look into that option as well as the yard “up river”. Both videos about replacing thru hulls in the water were educational. Didn’t know 5200 would cure underwater! Awesome. I will file the procedure shown under “we have no other option” for future reference. Between now and November haul out I will research the “seacock vs. ball valve” issue as well as the various brands preferred in thread responses. You gals and guys are the best. Always there when needed. Mahalo nui loa!