CPVC glue joint - gets wet inside while curing

[Vdawg]

Hi,

I was replacing a CPVC shutoff under the sink and turned off the house water supply first. I cut off the old valve and let the water run out of the pipe and dried everything. I created an assembly of a coupler, a 3 inch extension and the new valve (to allow enough stub for another replacement if necessary since the old one was only left about a 1 inch stub from the back of the cabinet.

Anyway, I glued the new assembly together, then glued the assembly to the wall stub where I had cut off the old valve, and held it for a 15 count. Seemed solid at that point. About 1 minute later, I saw water dripping from the open valve. I have TWO whole house shutoffs turned off and know they are holding as other faucets are open.

As soon as I went to the garage, I heard the hot water heater on, so I think it started to heat the water, which expanded. I do have an expansion tank, but the water expanded back towards the kitchen and bubbled out the new valve, meaning my new joints got wet about a minute after gluing them. I immediately turned off the water heater breaker to stop the expansion, but there is obviously water now in that valve. The joints still seem solid, but they didn't have the typical 20 minute cure time I would normally wait before turning on the water.

Is this joint now compromised and a disaster waiting to happen? Should I cut it all off and replace everything that was glued, which includes the valve? Doing so will probably mean cutting out part of the cabinet back to get enough stub to work with that wasn't part of the most recent gluing, so I'm hesitant to do that unless it's really necessary.

Thanks!

 

[Jeff H Young]

well its midnight now Im guessing you made decision . let us know what you did. I would have went shark bite because of the time of glue to dry even more when humid or wet

 

[Sponsor]

 

[Vdawg]

Yeah, I have SharkBite shutoff valves on my garage sink and they've worked well for 7 years. Even though I do like SharkBite parts, I always worry about them popping off, so the garage is ok if that ever happens. For under the kitchen sink, inside a nice cabinet... I'd like something a little bit more permanent.

So, I ended up cutting off the joint(s) that got wet. I was able to retain a little less than an inch in front of the cabinet panel , sanded it with 400 grit sandpaper to get rid of the excess glue on the outside, and rebuilt the assembly (coupler, extension, valve). This time I used a wet vac to suction out the line and got quite a bit of water. I turned off the water heater so it wouldn't expand any further. Then I let the pipe sit for about 15 minutes and it stayed dry inside so I figured there wasn't any water that was going to "bubble up" again. Just to be sure, I stuffed a ball of white bread in the pipe (a trick a plumber friend of mine taught me years ago), then glued the new assembly to the stub. I had to remove the escutcheon plate to get enough clearance, but I think I can get a split escutcheon back there if I want to later. Everything dried nicely for about an hour. Twirled a tissue into a thin string and stuck it in the open valve port (3/8 outlet) and it came out dry, so it seems the water did not come back this time while it dried!

Attached my supply line and opened the water main valve. All is well -- no leaks after several hours now, so I think I got it all working well. And I have about 2 inches of extension pipe between the coupler and the valve if I ever need to replace this valve (although they actually do unscrew from the part that's glued behind the CPVC adapter portion which is nice).

The original plumbers had actually used CPVC glue-on stops in all the bathrooms but not under the kitchen sink or for the toilet shutoffs. They're all compression fittings. Go figure. The CPVC stops under the bathroom sinks were the ones with the integral "crimped on" hoses, which had started to rust after about 7 years in place, so about a month ago I bought a bunch of CPVC glue-on stops at the big box and was able to unscrew the old valves, leaving the original CPVC adapter and metal female threaded part on the pipe stub, then screw the new valve into the existing female part -- the threads were the same. The new valves had 3/8" compression fittings instead of crimped-on hoses, so I could replace all the hoses and valves with hoses that could be replaced separately in the future. AND, the new valves are all quarter-turn instead of multi-turn like the old ones.

I used the same CPVC glue-on quarter-turn valve under the kitchen sink today. This kitchen cold-water shutoff feeds an undersink filter, so it gets used twice a year to replace the cartridge (I think the cartridge housing actually has a built-in shutoff but I close the supply valve anyway). The old multi-turn valve wasn't quite shutting off all the way, so putting a new quarter-turn valve in there is a big improvement. And I can replace the valve part in the future, if needed, without cutting the pipe -- just like I did in the bathrooms earlier this year which worked well.

 

[Jeff H Young]

Good To hear its holding well. glueing pvc and cpvc im super careful too. just had some 1 1/2 pvc 10 fittings irrigation. bought fresh glue took all precautions all went good too.
CPVC never caught on that big here from my view. Florida seems like it was way more common.
Ive had some of those 1 piece angle stop /supply lines that were push fit I couldnt get them to release. I used a shark bite x mip adapter and screwed a stop on made it easy for next guy!

 

[Vdawg]

Still dry over night, so I'm feeling better about it now.

I did also think about doing a male adapter and screw-on angle stop combo, but since I had already used these CPVC glue-on valves (8) on my bathroom sinks and had good luck with all of them, I figured I'd just stick with them. They are actually SharkBite brand, even though they don't use the push-fit connection which helps me sleep better. Since they essentially have a screw-on connection between the CPVC adapter and the valve body, the valve body can be replaced without cutting the pipe (see photo) which is what I did in my bathrooms earlier this year. I guess one downside to these is that they do have a rubber gasket between the CPVC adapter and the screw-in valve body which could wear down over time and leak, but that could be easily replaced as well.

 

[Jeff H Young]

should be good! might want to have a spare or 2 on hand.

 

[Vdawg]

Thanks! I actually did buy an extra at the store yesterday. The nice thing is they appear to be standard threading. The ones I replaced in the bathrooms were the same type of glue-on CPVC with the metal female adapter. But they weren't SharkBite (can't remember the brand now). I used SharkBite brand with the same type of assembly when I replaced them, removed the adapter from the new one and screwed the body into the existing adapter on the pipe -- fit perfectly!

 

[Reach4]

nyway, I glued the new assembly together, then glued the assembly to the wall stub where I had cut off the old valve, and held it for a 15 count. Seemed solid at that point. About 1 minute later, I saw water dripping from the open valve. I have TWO whole house shutoffs turned off and know they are holding as other faucets are open.

It gets wet inside, after the glued pipe has been pushed into the glued socket while dry, but was not pressurized for a good while? I would not worry a bit. I am not a pro.

 

[Vdawg]

Yeah -- the 3/8" port on the valve I was installing was open, so it didn't build up any pressure... just bubbled out continuously, most likely as the water heater was heating up and expanding the water in the tank.

 

[Tuttles Revenge]

OK.. just learned something that Oatey didn't tell me over the phone when I called them (per their instructions to call for cure times when doing repair work.. honestly they didn't sound like they knew their product)

https://www.flowguardgold.com/handling-aged-pipe

**Of course the chart that they link to on the specifications page for the above product.. doesn't include the above product.

***And the glue on angle stops are the best to use. You can change them out without having to glue on new ones. The glued on collar remains, but just change the rubber seal with the new stop.

 

[Vdawg]

Luckily, I used a mini-hacksaw to take off the old valve -- I couldn't fit the ratcheting cutters in there anyway, and needed to get as close to the old valve as possible to keep as much stub out remaining to work with. I did use the ratcheting cutters on the new CPVC stick I bought to use for this job, but since it's new I feel ok with it. But they do visibly distort the round shape of the pipe when they initially start the cut. I probably need to get some new sharper ones. Mine are about 10-15 years old. After reading that article, now I'd never used them on existing/installed pipe anywhere. I saw a YouTube video of a guy using an imp cutter on a CPVC pipe and it seemed to work. Not sure if there's any downside to that. Looked like a clean, square cut though.

I wonder how many years they consider CPVC to be "aged?" I'm sure environmental conditions matter as well. Mine is about 7 years old so hopefully not there yet!