Ball valve change out

So I'm finally going to change out the failed ball valve on my thru-hull today. This valve is for the AC cooler lines. The valve size is 1".

I bought one of these doodads to stop the flow of water when I remove the valve, then I thread the new valve over the red doodad then pull it out and close the valve. Allegedly.


Questions:

Am I a fool for trying this while the boat is in the water? Will I be overwhelmed by the amount of water shooting up when I remove the valve?

Should I use some of this thread dope on the thru hull threads?


Should I have the yard on standby for an emergency haulout?

Here's the old valve


Driving to the boat now so y'all have an hour to stop me before I sink the boat. ?

This could get very interesting! Best of luck, got a good bilge pump, just in case?

I have a bilge pump. It works. Not sure how "good" it is however. The boat also has a manually operated pump as well, and a small electric pump I use for flushing that I could rig up

Also have some of those wooden plugs.

What could possibly go wrong, right?

No worries. Very little pressure involved. I've done similar work. It's not that dramatic.

I'd suggest a wooden plug and wax toilet bowl seal as a backup. Enough stuff to temporarily repair so you don't have to play little dutch boy for too long...

A cell phone within reach to call backup might be a good idea.

Worst case scenario, you break the thru hull.

Definitely use a thread compound.

Northern Spy said:

No worries. Very little pressure involved. I've done similar work. It's not that dramatic.

I'd suggest a wooden plug and wax toilet bowl seal as a backup. Enough stuff to temporarily repair so you don't have to play little dutch boy for too long...

A cell phone within reach to call backup might be a good idea.

Worst case scenario, you break the thru hull.

Definitely use a thread compound.

Click to expand...

OK, thanks for that info. I just did not know if I was going to have a three-foot geyser shooting in my face.

Yeah my big worry is the thu hull threads breaking off for some reason. Is the wax seal used in conjunction with the wooden plug somehow?

If your thru hull is 4' underwater there will be about 2 psi differential pressure on a 1" hole will be about 29 gallons per minute. So say half a gallon per second.

So 10 seconds open time is only 5 gallons.

Ten seconds is a long time.

You can just wad the wax up and stuff it in the hole. It's just a cheap and readily available form of beeswax. A dollar store foam rubber bouncy ball is another good tool to have on board.

Another question:

When I attempt to unscrew that ball valve is there a possibility that through hull could start spinning?

I don't see any good way to put a back up on that through hull. I sure don't want to put a pipe wrench on those threads

I am kind of the Murphy's law of boat repair over here, so that is why I ask

Most thru hulls have lugs cast in the ID of them. You can use a "special tool" or a piece of flat bar, or a crescent wrench handle to keep it from turning. Might be tricky with a ball valve on there, if it is not a full port ball valve.

Probably won't need it though. Between the adhesive/sealant and the clamping force of the backing but, there is likely a lot of friction.

OK, again thank you very much for all the information. If the valve does not start unscrewing fairly easily I will probably just stop and rethink this.

A little penetrating oil and light tapping with a hammer loosens up frozen threads while you are thinking.

So after all the drama and worrying, I get to dock and realize I forgot the new valve.

Unbelievable. Will try again Thursday.

Northern Spy said:

If your thru hull is 4' underwater there will be about 2 psi differential pressure on a 1" hole will be about 29 gallons per minute. So say half a gallon per second.

So 10 seconds open time is only 5 gallons.

Ten seconds is a long time.

Click to expand...

My Bernoulli chart shows a 2" hole 4' underwater will permit ingress of 157.1 gallons per minute or 26.18 gallons in 10 seconds.

To the OP ..... before you touch anything be sure you are dealing with matching thread types. Most throughulls are NPS and many ball valves are NPT. You don't want to pull a Beneteau

cardude01 said:

Another question:

When I attempt to unscrew that ball valve is there a possibility that through hull could start spinning?

I don't see any good way to put a back up on that through hull. I sure don't want to put a pipe wrench on those threads

I am kind of the Murphy's law of boat repair over here, so that is why I ask

Click to expand...

Second Boatpokers comment re: threads - Excellent and Important Point -
see Thru Hull Primer if you aren't sure what he is referring to - Repeat Excellent and Important Point

I'd suggest a large crescent wrench on the thru hull flange nut - CW on the nut is tightening it and resisting the CCW rotation of the valve.

The bar inside only works from the outside or inside possibly if you don't use the red thingy... which by the way is a "Seabung".
I've seen the video but would appreciate a follow-up re: how it really worked when you are done.

cardude01 said:

So after all the drama and worrying, I get to dock and realize I forgot the new valve.

Unbelievable. Will try again Thursday.

Click to expand...

Glad to see I'm not the only one that has done that. Did ya at least spray some penetrating oil on it to help on Thursday?

Crusty Chief said:

Glad to see I'm not the only one that has done that. Did ya at least spray some penetrating oil on it to help on Thursday?

Click to expand...

I did!

CD

Why are you changing out the valve again? Why not wait until next haul out? If you want to shut of flow to ACs lots of options to do it safer and easier than your planned method. But some like to live on the edge or even thrive on it

sunchaser said:

CD

Why are you changing out the valve again? Why not wait until next haul out? If you want to shut of flow to ACs lots of options to do it safer and easier than your planned method. But some like to live on the edge or even thrive on it

Click to expand...

The valve broke closed shut. I'm not due for a haulout for quite some time.

Also I just wanted to see if I could do it, for future reference.

cardude01 said:

The valve broke closed shut. I'm not due for a haulout for quite some time

Click to expand...

Dude...
"Closed"???..
Using the seabung requires opening the valve and inserting it thru the opening????

Don
"Bacchus"

cardude01 said:

OK, again thank you very much for all the information. If the valve does not start unscrewing fairly easily I will probably just stop and rethink this.

Click to expand...

It's not uncommon for them to spin. And the special tool is designed to be inserted from the thruhull side not through the valve. So you'd have to have someone under the boat.

You can hold the threaded section of the thruhull beneath the valve with Vice Grips.

Why not have some one jump in the water and plug/hold the thruhull.

Bacchus said:

Dude...
"Closed"???..
Using the seabung requires opening the valve and inserting it thru the opening????

Don
"Bacchus"

Click to expand...

Yeah, my plan was to unscrew the defective ball valve, shove of the sea bung in the thru hull, then screw the new valve over the sea bung.

cardude01 said:

Yeah, my plan was to unscrew the defective ball valve, shove of the sea bung in the thru hull, then screw the new valve over the sea bung.

Click to expand...

Got it! - might want an assistant to be ready for step 2?

Capt.Bill11 said:

It's not uncommon for them to spin. And the special tool is designed to be inserted from the thruhull side not through the valve. So you'd have to have someone under the boat.

You can hold the threaded section of the thruhull beneath the valve with Vice Grips.

Why not have some one jump in the water and plug/hold the thruhull.

Click to expand...

Yeah I thought about getting someone (or me) to jump in and plug it from below. It's at the marina and I'm kind of scared-- the water is pretty gross. ?

cardude01 said:

Yeah I thought about getting someone (or me) to jump in and plug it from below. It's at the marina and I'm kind of scared-- the water is pretty gross. ��

Click to expand...

However...it is much more scary and gross filling up your bilge. You should definitely be prepared to take a dip and plug the through hull from outside if the 'doomsday scenario' should occur. I can relate to those conditions as I have helped change wheels while in a slip at Acadiana Marina (a canal and basin dredged out of the Louisiana marsh and full of pet gators..pewwww) and the marina at South Pass (at the south end of the Mississippi delta...the 'urethra' of the nation). The water clarity was not measurable in visibility but viscosity!

Yikes! Gators!

Ok. I will be prepared for doomsday. Thanks.

Update:

After staring at it and cogitating a bit, I've decided to get a Groco flange adaptor for this thru hull/ball valve mount. I don't like the way the ball valve just grabs the first few threads as it is now.

I don't really want to mount the flange to my hull with screws however-- way to much for me to mess up. Really just looking for the extra threads. Maybe mount it with 5200? Why do I have to mount it at all-- just screw that sucker on the TH and then the ball valve.

This thing

Check with Parks at Hopkins Carter. They have backing plates with a preinstalles way of attaching the flange to the backing plate.


just 5200 the backing plate down.


Just for info though....getting everything screwed together and lined up the way you want it may mot happen...ie the handle for the ball cock may thread on tight in a bad position....maybe not or maybe it does't matter where you are mounting it.


Plus the flange needs a certain amount of threads,,,have enough? Maybe too many and the flange won't bottom out?


None of these are insurmountable...even with the boat in the water...just the option of time is limited while fitting and guessing...


The flange adapters are pretty slick...what I used...so I wouldn't have to worry about what you are going though now with a 1 piece thru-hull.

cardude01 said:

Update:

After staring at it and cogitating a bit, I've decided to get a Groco flange adaptor for this thru hull/ball valve mount. I don't like the way the ball valve just grabs the first few threads as it is now.
View attachment 46457

Click to expand...

If it's just grabbing the first 2-3 threads then you have n NPS throughull on an NPT ball valve....... not a good thing !

If I were replacing a ball valve that broke, I would make the assumption the thru hull needs replacing as well. But then again I haul my boat every year for winter storage and replacing the thru hull on the hard is easy.

I think you are juggling with Jesus here; I would not do it this way myself, I'd wait until haulout or maybe pull a tarp across the bottom. My own experience with things that concern water is that
1. It will take twice as long as you expect it to and
2. It won't fit like it's supposed to so you will have to go back to the store and
3. The rush of water will give you a huge surprise, you will drop your gadget and it will immediately be grabbed by a bilge ferret which will take it far, far under the genset and you will not be able to retrieve it until your batteries are submerged.