PVC repair-coupling leaks

[oldee]

I found a leak in the connection of a 3" PVC drain during wet testing. I cut out the bad fitting and replaced it with a length of pipe that has a regular coupler on one end and a repair-coupler on the other. These pipes will not move lengthwise so a regular coupler can not be put on both ends. The repair-coupler has no center ridge so it can slide completely over one pipe and after the pipes are aligned it can be center over both pipes. I have tried this four times, cutting out more sections but I always get a leaky joint.

I install the pipe and regular coupler on one end before installing the repair-coupler. I put glue on the ends of both pipes, the repair-coupler and more glue on the pipes. I shove the repair-coupler on one pipe so it doesn't stick out, align the pipes and pull the repair-coupler back over both pipes. I try to twist the repair-coupler a quarter turn; the results vary but with regular glue I was able to twist it OK.

I have tried both Oatey Heavy Duty PVC Cement (green) and Oatey Regular PVC Cement (gold). The heavy duty stuff is thick and doesn't give me enough time. Once it dried so fast I couldn't pull the repair-coupler back over both pipes. Another time I was able to center the repair-coupler but it took a huge effort. The regular glue was much easier to work with but in all cases I ended up with a leaky joint. I test by filling the pipe with water after two hours of dry time. There is no pressure other than the weight of the water. This is what my inspector wants me to do.

Could it be too cold? Its about 50F in my attic where this problem is.

Is there a better technique? I noticed it leaks on the side of the coupler were the second pipe is attached. The pipe that I slid the coupler complete on before centering is OK.

With the heavy duty cement I cleaned the pipes with Oatley Cleaner (yellow). With the regular cement I cleaned the pipes with 100-grit sand paper. Could this be a problem?

Has anyone used these PVC repair-couplers? I doesn't seem like it should be this hard. I'd rather not use the rubber things.

...old-ee

[William.Deans]

Greetings,

a) there is nothing wrong with using a Fernco ("rubber things") b) if the glue works on the regular coupler it should also work on the repair coupler regardless of temperature c) is there a very small diameter mismatch? Try taking a regular coupler and removing the ridge to make it into a repair coupler. d) WORK FASTER. I know it is hard but don't let the thing sit around for the glue to harden. e) Does it always leak on the same side of the repair coupler? For instance, does it always leak on the side you slide it onto or the side you slide it off of? You might try sliding it 2/3 onto the side it always leaks from instead of 1/2 onto each side.

Hope this helps, William

[SQLit]

3 inch PVC in the attic? If it is not a vertical pipe then there is something different about your installation than what I am familiar with. 2 hours at 50 F pretty short time frame. Better let it sit over night.

What color is the pipe? If it is black, ABS then you maybe using the wrong material and cement.

[oldee]

Thanks for your prompt replies.

The pipes are the same nominal size. When dry the coupler fits real snug on both pipes, it takes some effort to slide it on either pipe.

I'm not sure if it always leaks from the same side. Sometimes it leaks on top, sometimes on bottom but I can't remember which pipe I slid the coupler on first except the last time. The last time I did it it leaked from the second side.

It is a vertical pipe. Its actually in the stairway on the way up to the attic. Its not in heated space.

I'll let it sit longer.

This is white PVC pipe.

...old-ee

[Bob]

fits real

either pipe.

Sometimes it leaks

pipe I slid the

it it leaked

way up to

You can try a bead of PVC cement on the outside of the leaking pipe after it has dried. If you can somehow create a slight vacuum in the pipe while applying this, it will suck cement into the void and do a better job of sealing. I have had some success using this method. YMMV.

Bob

[RicodJour]

You cleaned the pipe, but did you use primer? Cleaner just cleans, primer cleans and softens the PVC making for a better weld.

Fernco couplings would be a good, quick solution for you.

R

[hwm54112]

Use primer instead of cleaner. Primer comes in clear or purple and is very different from cleaner. Using primer eliminates need for cleaner, softens pipe and retards initial setting time of glue substantially. Glue pipe, then fitting, slide fitting on. Glue pipe again and slide into place, twisting fitting back and forth or rotating constantly as you slide it until centered.

[CJT]

FWIW, my plumber told me always to use the purple primer followed by the green-can clear cement. I have, and I've never experienced a problem. Follow precisely the instructions on the cans.

Works for me; I hope it does for you.

[DanG]

The most simple solution would be to use no-hub band clamps on both joints with no glue.

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[Don Young]

[oldee]

Thanks for your suggestions.

I had been using cleaner and primer interchangeably. I didn't realize they were different. On this joint I used cleaner or sandpaper.

hours for 10% of rated pressure and 20 hours for 100%. I calculated the wet test pressure to be 2.6 psi; it has 6' of water above the joint.

I tried RicodJour's vacuum and bead suggestion. It sounds like a great idea. Since the pipes are plugged for the wet test, I put a small board on the remaining opening at the top of the pipe. I opened a drain an easily hooked up my shop vacuum before apply some glue to the joint. I'll test it after it dries.

...old-ee

[wkearney99]

You have a drain running through an attic? What're you doing about making sure it doesn't freeze?

[CJT]

How often would you expect a 3 inch drain in an attic to be full of water?

[oldee]

The vacuum / glue bead suggestion worked. My leak is gone. Thanks Bob! I unintentionally suggested this was somebody else's idea in my last post. I created a vacuum in the pipe with a shop vac while I applied glue to the bad joint.

I'm finishing my attic and installing a bath. This pipe will eventually be in heated space. Of course almost all houses have vent stacks in the attic, put they don't get wet because they are above all fixtures.

I expect my pipe to be full of water one more time during the rough plumbing inspection.

Thanks for all of the suggestions, old-ee.

[RicodJour]

Not exactly. Depending on where the vent is it can carry rain water caught at the roof vent. I found that one out the hard way on one project - eight years after the fact. The plumber hadn't glued the PVC correctly and had used some silicone caulk to "fix" his ineptness. Eventually the caulk failed and the leak showed up as discoloration on the drywall ceiling near a wall.

The pressure test is overkill for a vent, but I understand the reasoning and don't know of a better way to accomplish a watertight test.

R

[Bob]

Thanks Bob!

Glad I could help. You are welcome.

Bob