I need help figuring out a sealant to use in my pool

[jztemple2]

I have a 40 year old pool. Over the past couple of years I have had several leaks in the main drain pot at the bottom of the pool. I've had American Leak Detectors (ADL) come, identify the leaks and use epoxy to seal them. The leaks are coming from cracks in the plastic of the main drain pot, near the top where the several resurfacings I've done over the years have no doubt stressed the wall enough to cause the cracks. This latest leaks however has been so severe that ADL has advised me to seek a better solution.





So I was considering filling the whole "pot" with hydraulic cement, but I talked with my brother who is a concrete expert (like an actual paid consultant) and he says do NOT fill the pot with concrete, because concrete shrinks and cracks. He instead recommends that I chip out the old epoxy and use a sealant on the cracks. However, he is not an expert on non-concrete sealants.

So this is my question to you folks, what sealant can you recommend? It has to be able to be applied and stick to the plastic (PVC?) walls of the drain pot and remain flexible and "plastic" down to temps of about forty and up to ninety. And also this fix would be at the bottom of six feet of chlorinated water. Any help would be appreciated.

[FishPants]

If you fill the drain with concrete.. doesn't the pool become a problem to drain? Anyhow I guess you could fill it with epoxy?

[jztemple2]

If you fill the drain with concrete.. doesn't the pool become a problem to drain? Anyhow I guess you could fill it with epoxy?

I can always drain the pool using an external pump and hoses; opening that drain plug at the bottom of the pot would be allowing 21,000 gallons of water to flow under my pool, which isn't a good thing. Most of my pool water did drain out through the cracks in the pot, over 25,000 gallons (I was trying to keep it filled for a while) but that took about a month so the water had time to percolate down through the soil.

Right now I'm thinking a bit outside the box, err, pot. Instead of trying to seal the cracks in the sides of the pot, I'm thinking that perhaps I could make a plastic lid for the pot that would sit on the top, within the outside rim (where the 3" and 11" inch marks are in the top photo), resting on that half-inch wide inside rim. I'd use some kind of epoxy to seal that lid in place and make it water-tight. The lid would have to support a column of water six inches in diameter and about six feet high, about 75 pounds.

[Smoove_B]

So I was considering filling the whole "pot" with hydraulic cement, but I talked with my brother who is a concrete expert (like an actual paid consultant) and he says do NOT fill the pot with concrete, because concrete shrinks and cracks. He instead recommends that I chip out the old epoxy and use a sealant on the cracks. However, he is not an expert on non-concrete sealants

I'm surprised he didn't suggest the use of a cement mixed with bentonite. Maybe ask him about that as the bentonite/cement mixtures are explicitly used to grout well casings because it won't shrink when wet - it expands (because of the clay). Granted, grouting well casing is different than plugging a pool drain so obviously defer to the expert.

[Montag]

If the horizontal hole was plugged would it solve the problem? Could you use a silicone rubber stopper?

[jztemple2]

If the horizontal hole was plugged would it solve the problem? Could you use a silicone rubber stopper?

The horizontal hole isn't involved, it just a line that runs up to the skimmer box. American Leak Detectors pressure tested it and said it wasn't leaking.

I've also arrived at a solution... a small dinner plate . Inverted it would rest on that flat rim. It's a little smaller than I would have liked, but I'm still looking. I'd put silicone sealant on the rim, press the plate down on it to make sure it seals all the way around, then let it dry. I can fill the pool at one foot increments, stopping each time for a day to take measurements.

The advantage of this (if it works) is that there is no water in the main drain pot anymore, so it doesn't matter if there are cracks there. And if for some reason it just totally doesn't work, using a flat blade screwdriver under the edge of the plate will pop it off; no harm done to the pot or the pool.

I'm still mulling this over but it does seem to be a winner. Now I have to figure out which is the best silicone sealant for this application.

[Punisher]

Wouldn't a plate have a high risk of breaking?
I'm assuming you use the pool so if someone stepped on it it might break and cut them.

I'd go to Lowes, Hone Depot, or similar. Look in plumbing and see if you can find a plug that fits. Even a PVC cap then seal it like you planned to with the plate.

[Scraper]

[Scraper]

Seriously though I'm of no help, but I couldn't get that stupid picture out of my head just from reading the thread title.

[jztemple2]

So, progress has been made!

I had a pool repair guy out here to look at it. He was amazed, there were three additional plastic rings installed above the original drain pot, each time the pool was resurfaced. He thought he might have an epoxy that would work, but wasn't sure. The next solution (for him) was to cut out all of the rings and the drain pot and start fresh.

I suggest an idea I'd been toying with, just putting a blank plate on top of the opening. He said that might work. I noted that even if it doesn't it doesn't cost me more than the lost water and a few bucks for parts.

So I've installed the blank plate, which I cut out using a jig saw from a piece of plastic cutting board. I sealed it in with silicone sealant. After a couple of days of letting it set, I'll start filling with water, a foot at a time.

[jztemple2]

This will probably be my last update for this thread, hopefully

I filled the pool, a foot each day and took measurements and surprisingly (to me at least) my kludge fix worked! It's been over a week now with the pool filled and I haven't needed to top it off at all. A few days ago the solar panel guys fixed the leak I had been delaying to have fixed until I had water in the pool and yesterday I got a new o-ring for the pool filter which as almost gotten rid of the annoying drips, well, annoying to my wife . With the warmer days I ought to be able to be swimming in the pool in the next few days.