Return Port Flange Leaking at Pool Wall...What is best glue?

etbrown4

Well-known member
Feb 24, 2012
75
In a gunite pool we have several return port flanges leaking at the pool wall.

The leak shows itself when winterizing and blowing out the return lines with air. With the rubber stopper tightly in place, a lot of air leaks between the flange and the pool wall. Clearly if left unaddressed, pool water will re-enter the return pipe and we no longer have winterized pool return lines. This matters because we have hard wintertime freezes in our area! Draining the water below the ports won't help for certain, as lots of rain can easily refill the pool to that level.

With gunite and plaster walls are we better off with silicone "glue", some kind of epoxy or what, trying to seal that outer flange to the pool wall?

We're not thinking about plain silicone, but the 'silicone glue'. Or maybe the two part putty-like epoxy, or maybe the usual two part epoxy that is runny, though that seems unlikely as, there is nothing to keep that from dripping off the fitting.

Tips appreciated
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

Several things would likely work but I would consider polyurethane caulk. You are not trying to "glue" two surfaces together but, rather, are sealing a moving gap between these surfaces.

Polyurethane caulk does that very well as it will expand and contract better than glue or epoxy.
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

The pool wall is still holding a fair amount of moisture even though the water level is 6"" below the returns.

Would the polyurethane stick to pool plaster that has moisture content? That was one reason I thought the two part epoxy putty - known to bond to damp surfaces - might work pretty well.
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

Nor sure if epoxy would adhere any better than poly caulk....just don't know.

Of course, the correct solution is to fix the leaks. The return lines should not allow air to leak around the sides of the flange and indicates an incorrect assembly of that connection.
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

There are a few different models of wall fittings. There are some that are glued onto the piping and some just slip into the piping. You may have the type that slips in and therefore they will leak around them when trying to winterize using plugs.
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

I'm hoping to try one of these this weekend, so any tips would be appreciated!

Any thoughts on whether polyurethane caulk might be better than silicone, and why?

My chief concern is there will be some residual moisture in the plaster wall when I drain it down, wait 4 hours, use a hair dryer etc !
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

Any thoughts on whether polyurethane caulk might be better than silicone, and why?

1. I would not make that connection "permanent" with epoxy....you may have to remove that flange some day.

2. As I said above, that is a "moving" joint and poly will flex with the joint much better than epoxy
 

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Re: Return Port Flange Leaking at Pool Wall...What is best g

Thanks for the reply Dave. I had enjoyed taking with you last year on pool chemistry and you were a great help.

I got you on the epoxy! clear enough.

This morning I was asking about polyurethane vs silicone.

Do you have a feel which would be better, as I'm a little leary with some residual moisture in the plaster - even with a hair dryer.

Many thanks!
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

Poly is a lot "stickier" than silicone and will address the legitimate moisture concerns you have.

Poly is not as easy and clean as silicone.....done carelessly, you can make a real mess. Silicone will work, and is easier to apply but the poly is the best for that particular application
 
Re: Return Port Flange Leaking at Pool Wall...What is best g

Ok, polyurethane applied between pool wall and return port flange.
That should do a good gob preventing pool water from seeping into the back into the return lines in the winter, and causing a freeze risk.

That brings up the second issue as mentioned by Dave earlier. Apparently there is still a likely leak inside that return port. It's most likely at the point at which the
1 1/2" pvc is glued into the back of the return port. Under pump pressure it seems there is a good chance that return water could be leaking behind the plaster and through the concrete wall.

Because the return flange is flush with the pool wall, the 1 1/2" pvc has to be either flush with the wall or back an inch or so. If you break up the port, it seems that you might have a hard time getting a clean end on that pvc that you could glue a new port to.

Given the challenges, does it make sense to try to place some of the putty-like epoxy inside the old port, around the inner diameter, right at the point where the pvc glues into it? One would think this might correct the original problem. Tips appreciated.
 
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