Can cracked PVC be repaired?

[JimK]

I noticed the other day that the collar that the flow sensor screws into (I have a SWCG) has a fine crack and is leaking a little.

I thought about just putting some epoxy (I have some marine epoxy on hand that I used to repair a Hayward Viper cleaner) on it, but someone mentioned they didn't think epoxy would stick very well to PVC.

Because of the way the flow sensor pipe was installed, very close to other joints, replacing the whole piece would be difficult, so I was hoping to be able to patch/seal it somehow.

Suggestions are greatly appreciated.

[jwhouse]

I've done a good bit of work with PVC and have never attempted to "patch" using glue or epoxy. If there's any pressure at all, I would think that just trying to patch the crack wouldn't work. I have, however, used repair couplings to "fix" cracks in pipe. These couplings are without the stop ribs inside and allow the coupling to slide all the way onto a piece of pipe. Not an easy thing to do depending on where the crack is but possible. Only problem is that the pipe would have to be cut to patch in this manner. This still doesn't help since it sounds like the crack you are dealing with is on a collar.

Good Luck Jim!

[JimK]

I've done a good bit of work with PVC and have never attempted to "patch" using glue or epoxy. If there's any pressure at all, I would think that just trying to patch the crack wouldn't work. I have, however, used repair couplings to "fix" cracks in pipe. These couplings are without the stop ribs inside and allow the coupling to slide all the way onto a piece of pipe. Not an easy thing to do depending on where the crack is but possible. Only problem is that the pipe would have to be cut to patch in this manner. This still doesn't help since it sounds like the crack you are dealing with is on a collar.

Good Luck Jim!

Thanks for the feedback. Yeah, the crack is in the collar that sticks up perpendicular to the pipe. You've got me thinking though, perhaps I could make a patch out of a small piece of PVC and attached using PVC glue? It would only need to be a very small piece since the crack is very small. I'll take a closer look at it and see if that may be feasable.

Meanwhile, keep the suggestions coming.

[jwhouse]

I would think that the key would be to have something that went completely around the collar to take stress off the crack. If you could somehow glue it then put a hose clamp around it, that might work temporarily. I would recommend changing it during the off season though.
When using PVC glue, you are essentially "melting" the plastics together and when it cures, it forms a solid piece.
Be sure if you try anything, to make sure that the glue you use is wet applications and you will need to shut your pump off for a bit to relieve pressure from the line to give the glue ample time to cure.

Here is the information link to Rain-R-Shine PVC Cement: http://www.oatey.com/Channel/Shared/...ue_Cement.html

[JimK]

I would think that the key would be to have something that went completely around the collar to take stress off the crack. If you could somehow glue it then put a hose clamp around it, that might work temporarily. I would recommend changing it during the off season though.
When using PVC glue, you are essentially "melting" the plastics together and when it cures, it forms a solid piece.
Be sure if you try anything, to make sure that the glue you use is wet applications and you will need to shut your pump off for a bit to relieve pressure from the line to give the glue ample time to cure.

Here is the information link to Rain-R-Shine PVC Cement: http://www.oatey.com/Channel/Shared/...ue_Cement.html

So you think the marine epoxy would stick to the PVC well as long as I can support it with a hose clamp?

BTW, just for clarification, there's no water squirting out, just a very, very slow drip. I only noticed it because the concrete pad underneath was a little wet. Even then it took me awhile to find the small crack in the collar.

[jwhouse]

Jim, I'm not sure about marine epoxy but something that was made for use on PVC might. As for the amount of or speed of leakage, I don't think it would matter when attempting to patch it. Any pressure forcing even the smallest amount of water past the glue during the patch phase could cause channeling in the patch spot and allow the leak to continue.
If I were going to try to patch it temporarily, my steps would probably be something along the lines of:

1) Turn pump off to remove as much pressure as possible. Also close any valves that would prevent any natural pressure from the pool itself.
2) Apply a portion of the Rain-R-Shine PVC glue to the affected area.
3) Attempt to bond the two sides of the crack together with a small piece of PVC cut off of of some spare pipe.
4) Secure it with a hose clamp around the cracked area to relieve tension from the outward pressure
5) Allow glue to cure for at least 15 minutes before reapplying pressure.

One more thing to consider would be that the reaction the glue has with the PVC during application, the more glue you use the weaker the PVC will become so this wouldn't be a "the more the better" scenario.

Remember, all this is definitely not a recommendation but merely a thought thread on the possibility of patching the crack. My actual recommendation would be to replace the collar.

[JimK]

Jim, I'm not sure about marine epoxy but something that was made for use on PVC might. As for the amount of or speed of leakage, I don't think it would matter when attempting to patch it. Any pressure forcing even the smallest amount of water past the glue during the patch phase could cause channeling in the patch spot and allow the leak to continue.
If I were going to try to patch it temporarily, my steps would probably be something along the lines of:

1) Turn pump off to remove as much pressure as possible. Also close any valves that would prevent any natural pressure from the pool itself.
2) Apply a portion of the Rain-R-Shine PVC glue to the affected area.
3) Attempt to bond the two sides of the crack together with a small piece of PVC cut off of of some spare pipe.
4) Secure it with a hose clamp around the cracked area to relieve tension from the outward pressure
5) Allow glue to cure for at least 15 minutes before reapplying pressure.

One more thing to consider would be that the reaction the glue has with the PVC during application, the more glue you use the weaker the PVC will become so this wouldn't be a "the more the better" scenario.

Remember, all this is definitely not a recommendation but merely a thought thread on the possibility of patching the crack. My actual recommendation would be to replace the collar.

Thanks for the great tip.

Would you suggest I remove the flow switch before trying the repair? Or is that likely to cause more problems when I try to reinstall it? Also, I'm guessing I should leave the hose clamp on to counteract any outward pressure? And do I need to use PVC cleaner before applying the glue?

Thanks again.

[jwhouse]

Unless the flow switch is in a place that would require the glue to be put on it, I would leave it in. If you will end up with glue on the flow switch without removal, I would take it out.
As for the hose clamp, yes, leave it on.

Hope it works out for you. Will be a cheap temp fix with very little labor involved so even if it doesn't work, the worst case scenario would be that you have to replace the collar anyway.

Let me know how it turns out.

[JimK]

Unless the flow switch is in a place that would require the glue to be put on it, I would leave it in. If you will end up with glue on the flow switch without removal, I would take it out.
As for the hose clamp, yes, leave it on.

Hope it works out for you. Will be a cheap temp fix with very little labor involved so even if it doesn't work, the worst case scenario would be that you have to replace the collar anyway.

Let me know how it turns out.

Thanks.

While you were posting, I added this question;

Do I need to use PVC cleaner before applying the glue (like you would when connecting PVC pipes)?

[jwhouse]

I doubt it will matter for this.