20 Best Underwater Sealant For Pools (2023 Updated)

Purchased this product to re-attach 20+ pool tiles (above and below water line) for my sister’s in-ground swimming pool. Using this adhesive with a caulk gun was fast, easy and clean. I tried pulling a tile off the next day to test the adhesion and couldn’t get it to break free.

DON’T, I repeat. DON’T waste your money on other adhesives, this is the real deal. I will never waste money on any other brand adhesive again.

Some tiles fell off the edge of our pool and this product was simply amazing. It glued that back on in no time even under water and i was able to do even the grout lines. Perfect solution that saved me having to look for someone to fix it.

works great. sticks to everything under water, clean up a bit tricky but I had great results with spa leak problem, so happy. bit expensive, wish they had 1/2 size tube.

I am pretty sure with this sealant I have created the first swimming pool that makes its own water. All jokes aside Wild West got this out quick and this stuff was quick and easy to used!

I’ll give it five stars because of how easy it was to work with but I never use it under water yet I won’t know how it will really perform until I fill up my pool and see what happens after a few years but right now I give it a five.

A bit expensive, but did work as hoped, under water. Very satisfying.

We had a small crack in our inground pool and was losing a little bit of water every day. We used this and no more leaks! I highly recommend it!

This is the Best product I have found. This is the first pool repair product I have used that works just like it says. Very Pleased with this.

This is a great product with good instructions. Saved us from spending hundreds of dollars sealing our pool tiles with a professional. This product does it’s job and our pool tile leak is no longer!

My built-in sunken hot tub in a small custom-added redwood room stood unused for about 22 years. I thought it would be cheaper to fix it and use it for therapy than purchasing a therapeutic bath tub.

When I fired it up I found many problems including that it had three small leaks – all three were visible or made visible by disassembly of the outside spa pack. None of them could easily be fixed by patching – without really getting expensive.

I did some research and found “Fix A Leak”. Since my hot tub was only about 300 gallons, I thought I wouldn’t need the whole bottle at one time. So I treated in thirds – following the on-bottle directions.

The leaks slowed but didn’t stop. I think I ran the pump for a total of 10-12 hours the first time. Since there was some progress, I bought a second bottle. I put the whole bottle in at once following the directions and not changing water from the first treatment.

After running the pump another 10-15 hours, the leaks started to really close down. So I ran the pump another 10-15 hours and the leaks completely closed. I let the tub stand with the pump off for a few days, then started the pump, ran it, heated the tub, let it cool, heated it again, and finally satisfied myself that it wasn’t leaking anymore.

It wasn’t and it hasn’t forthe past week. I don’t know what it will do down the line, but it’s good now. The secret is keeping the active crystals in solution and keeping them circulating. I could see the leaks and when they stopped leaking, I could see the crystals coming through the leaks from the inside and drying when they hit the outside air – stopping the leak.

They also change color to a yellowish brown – this was a very small amount but I could see it happen. So the secret is to use a lot of “Fix A Leak” and let the pump run a long time. Keep the crystals in solution – you will see them settle to the bottom of the tub.

I used a broom to keep them stirred up and ran the air injector to really remix them in the water. Keeping running the pump It works. Then I emptied the tub, put the filters back in, refilled and heated.

Everything, as I said, is good so far.

hello i have a large vinyl liner in-ground pool leak lousing 1 inch of water a day. i tried this product instead of calling the pool guys. it started to work on day two of the repair only lousing 1/2 an inch but that only lasted a day and the leak continued.

still lousing an inch of water. if a had to do this over i would have used two bottles of fix a leak , maybe giving me a better shot at fixing this leak.

After figuring out how much fix-a leak I needed , I pour it in my tub as directed ran tub for 2 days and was amazed that the leak had been plugged . A product that does what it says nice!

Still working on it. I have a crack on the side of the pool. Peeble Crete Pool, still trying to see if its working. Have used 1 bottle so far and will wait and see. I really hope it solves the problem.

I have squirted it direct on the crack and put the rest in the filter box as directed. Waiting to see. 2nd report. I need to wait for a storm to fill the pool so I can use the 2nd bottle I purchased.

I need the pool full and I’m not going to fill it out of the tap. I have a divertor from the roof so it doesn’t take long to fill if we get some rain. Ever. At this stage I’m very pleased. Will let you know.

Great follow up guys.

Our indoor spa developed a small leak from underneath. Our local spa specialist advised that to properly find and repair the leak would require draining the spa, raising it on blocks, partially refilling, running the pump, locating the leak, marking its position, draining the spa, turning it on its side, digging into the foam, hopefully finding an obvious crack or defect and repairing it.

Refoaming around the repair was optional. Of course, hoping the repair was successful and it was the only leak. While searching for the weight of the spa empty to determine how hard it would be to get up on blocks, I happened across this stop leak product with mainly glowing reviews.

Reading about the failures, I made the assumption that some leaks are just outside the effective realm of this products useful range. I was hoping our leak would be exactly what the product was intended for.

For the very reasonable cost of this product, I figured, what’s the harm. It works, I’ve saved a lot of work and the $60. an hour spa specialist repair rate. So, I ordered one bottle, understanding that should allow two or three treatments.

Wow, I think the bottle arrived within one or two days. I removed the filters, turned the pump on and poured 1/3 of the bottle into the area where the filters go. Ilet it run for several hours. It’s been almost a week now and no leak! Obviously, it’s too soon to know if this is a long term solution to our leak, but so far so good! For the price, even IF I need to retreat once or twice a year, that is better than the alternative.

Fingers crossed :-).

I have leakage at the return line of my swimming pool and did the procedure once, it last for couple of weeks and the leak returned, did the same procedure twice and the leak returned again. Procedure: 1.

closed the return valve at the pump so the line separated from the pump. 2. closed all the return nozzle so the water is kept in the return line. 3. tied a flex hose with a bucket attached to it to one of the return nozzle.

4. elevated the bucket 5 feet high so the water in the bucket would pressure the closed return line. 5. filled the hose at the bucket with the product. 6. kept the bucket filled so the water and product would go through the leak for over 10 hours, the leak was not so bad and the bucket was almost empty after 10 hours but the hose was filled with water and the product remaining in it.

7. after 10 hours the leakage stopped and the water in the bucket didn’t lower. 8. left the set for another 24 hours. 9. started the return line and it was ok, 10. a week later the leakage returned.

The product may be fine, but the tube and nozzle are terrible. The nozzle doesn’t stay attached to the tube, so you need to hold it on with one hand while squeezing the tube with the other. It makes application awkward and messy.

If you don’t hold it on, the sealant gets everywhere. I thought I got a bad tube, so bought another one for $13 and it did the same thing. I expect better from 3M.

Easy to use marine grade sealeant fixed a leaking windshield on my boat in minutes. Dry to the touch in 10 minutes.

Product works well. Skins over in 15 minutes. Most sealant tubes have a cap that you use to break the sealant tube seal. This one does not so, make sure you have something small and sharp in order to break the aluminum seal under the cap.

I used this sealant when I mounted a table pedestal base to my boat. It worked well.

Not for underwater use. I know it says waterproof, but this product is not designed for long term submersion. According to BOSS Products support, the 802 formula will start to breakdown after being underwater for approx 30 days.

It will lose it’s grip on the surrounding surfaces and allow leaks to form. This is exactly what happened around my hot tub skimmer. I made sure to remove all the old caulk and clean the surfaces. For long term underwater submersion, BOSS suggested I use their 801 product.

I purchased the product and so far it has remained water tight. Spa Depot was kind enough to refund my purchase price, so the review only effect the product.

I am using it in my showers and kitchen amazing results. Best product ever! Tried other brands with no good results Highly recommend it!

Hard to find product. Product was what I wanted. Thank you!

This product worked exactly as advertised. A little goes a long way. I used it to seal the grout between the new countertop and existing tile backsplash. If you use too much it looks like there’s a bunch of Vaseline so use sparingly.

Just enough to put a sheer layer is enough for waterproofing. A couple of notes: You will see a bunch of reviews saying the container exploded on them. This is most likely because they didn’t break the seal.

You need to poke a hole in the seal in addition to cutting the tip off. Also, the product smells very strongly of vinegar. I don’t mind it. In fact I prefer it to the chemical odor of other sealants.

All in all I was very happy with this product.

I allowed this to cure for over 48 hours and it seemed dry and set. But the first time it got damp it turned to sticky jelly! I noticed there was no use by date on it which concerned me. But after using it it seemed to set well.

It never occurred to me that it wouldn’t hold up to dampness. And it was a brief period of dampness. This is the third Gorilla product I’ve bought from DiscoverMyStore, and all three have been unsatisfactory.

I’ve learned my lesson.

Item was very messy because tubing is not sturdy. The base of the tube kept popping off and the silicon was very hard to get to come from the top of the tube. Had to throw the entire tube away because the base kept sliding off and couldn’t stop the product from seeping from the top.

Really messed up my project. Not the seller’s fault at all. Just not good packaging for the product.

Easy to use underwater, ***. works much better on a dry surface. If you are using it to fix/seal a skimmer, I have had much better luck in the spring before adding water. It’s tough to use because it sticks to your fingers, but seals much better.

Use some water on your hands to smooth the epoxy once in place. The price is substantially more than the non-colored/whie product, which in my opinion is a bit ridiculous.

Always amazing me you can get products in 1 day! Use the Epoxybond mostly underwater trying to fix a leak in our concrete contemporary koi pond. Easy to use; however, in several under water applications the product turned gray.

Above the water line it always cured black.

Easy to mix and hardness quickly under water. I used to repair cracks and peels in my pool’s floor, and also to cement stained corals into cinder blocks for a long term experiment.

This sticky rubbery stuff will seal anything. I recently replaced the liner on my pool and the skimmer leaked. The local pool store said that is very, very common and that they always use a sealer when they replace a liner; just to make sure the skimmer and return seal and they don’t have to come back out a second time per job.

At the time they were out of sealers so I bought on DiscoverMyStore. I bought two tubs but I only needed half of one tub. There is a small applicator nozzle under the lid that is just long enough to get behind what you are sealing.

The blue color is slightly lighter than my blue liner but you can bare tell the difference. I wish I had this stuff when I installed the skimmer so I didn’t have to do the job twice.

At first I tested the product on a piece of wood in a bucket full of water (of my pool) to check the behavior of the material and its resistance to water for several days. The material does harden but it seems that even though several days have passed it does not harden and stick to the wood The disappointing findings I made with the material sealing of cracks that formed in my fiberglass pool and let the material work.

the material itself is relatively easy to operate. maybe with it was harder and stickier and less liquid it was easier to operate especially underwater. And the material works great, hardens, sticks and seals the cracks satisfactorily.

The end result is satisfactory and in deciding to show that the product works well underwater and does the sealing job well despite my first test that did not show it. recommend this product !!!.

I use this product a lot on my job. Works in place of Teflon tape and other applications around the house. If you don’t mind getting it on your fingers use latex gloves or you have to wait and peel it off fingers.

It certainly works as I was able to mend two holes in my butyl pond liner! One the size of a pencil the other the size of a postage stamp that was awkwardly on a crease. Bit what is odd is you’re instructed not to press the patch down hard to form a seal, which is the instinctive thing to do.

It’s actually quite hard not to especially in situ. However tapping the patch gently leaving a few millimetres gap it worked. but I wish they’d explain why not to press firmly! Great product.

Hello Pond Enthusiasts, I had a rip in my old PVC liner deep in my pond 4′ down near the bottom. To make matters worse, this was not on a simple flat place, but rather a rip that traversed 3 folded pleats that hung down over one another.

It seems the former owner thought he could tree train a pine next to the pond to lean over it by tying a fishing line to a large boulder sitting on the bottom. All this did was make an excellent band saw that chewed into the liner.

The liner was old and thus stiff and no longer pliable. The fishing line had chewed through the pleats and into the rear of the creases. I tried an underwater 2-part epoxy which was very sticky and expensive – which did not work.

Further I added small stiff patches trying to rebuild the pleats then tried an underwater putty. NOPE! In desperation, I tried this product. Not only was it very friendly to work with, I was able to easily cover the previous patches, the deep creases behind the folds and over the existing patching using a caulk gun.

It cured in unusually warm weather in a couple a days just before a big snow storm. The snows lasted weeks and by the time it melted I noticed the melt water had not moved a bit and the liner was holding water once again.

I’ve not found anything better yet than this Sealant yet great for repairing puncture holes from the last Heron visit, due to it’s underwater sealing ability and saving time from draining the pond just a piece of clean pond liner and this sealant does the job perfectly.

You must read and understand the instructions before starting the repair. This sealant I rate as Highly recommended 5 stars.

I got this item to use on a vinyl seam. It doesn’t get tacky so that sucked and obviously didn’t form a bond. I figured since I already got it I’d just use it on my sink since it needed caulking. The applicator tip doesn’t stay on like the other reviews said.

But I still managed to apply it okay with my fingers. It does dry clear, which is about the only positive. After 24 hours I cleaned my sink area, it instantly started to ball up and come away from the sink.

So if you are going to use this as intended, I’d leave it for more than 24 hours untouched then see if water and a rubbing motion starts to pull it off. Definetly don’t see how this could be labeled as something to use with marine related items.

After reading other reviews decided to use this to reseal the awning rails on my caravan. I’m not disappointed. Very easy to use and sticks really well. I’m now more than confident that I won’t get any water ingress into the caravan.

Will definitely be using for other sealing replacement jobs I intend to do.

Good adhesion, waterproof, easy to smooth, does the job well. Beware that if it gets on your hands, it takes a long time to get rid of it, so wear disposable gloves and be careful they don’t split. Also watch out when cleaning up – it has a tendency to get everywhere.

Once opened, the original nozzle may not be usable after a couple of weeks of storage, so best to have replacement nozzles available if you plan to reuse the same cannister. I have used it for all kind of sealing applications (hatch, windows) and for sticking flexible solar panels to a narrowboat roof.

Excellent adhesive and sealant properties. Once cured it’s bond to the surfaces is very strong and it is flexible enough that it remains in place over time. We tried various automotive products, but nothing comes close to this.

Excellent.

I was nervous about buying this kit, as I couldn’t find any reviews on line or any details about the cement. I wouldn’t trust any patch kit until it proved itself in use, but this one did! I had a pinhole leak in one of the bottom channels of my Explorer kayak.

I did some research on line about how to repair such leaks. Two layers (blobs) of this cement (with no patch) worked like a charm. I left an hour or so between applications and then let it cure for 24 hours before putting pressure on it.

I then inflated it in the house and left it overnight to be sure it didn’t leak, then tested it on choppy water with two people in the boat. No problems at all. Although they were not used for this repair, the patches are a perfect color match for the Intex K2 Explorer and seem to be identical material.

My air bed started losing air at 4 months old, on top of bed where coating is. Used rubbing alcohol on area of hole, and scraped coating off with thumbnail. Applied glue on mattress and patch and stuck patch on, then covered patch with the clear plastic in kit overhanging patch about an inch and put some heavy books on it for about 2 hours.

Clear plastic was for excess glue squeezing out, so books didn’t get stuck to mattress. Working great so far.

I have a twin AeroBed air mattress that had a hole in it and was going to lend it out to a friend. I found this patch on line, purchased it and applied it as instructed. The next day I inflated the air mattress and to my surprise it worked!! I was thrilled!! I cannot thank you enough for selling this product!!.

Had to re-cement the main drain in an indoor pool and after it was completed the water level was going down slightly over a few days. Poured Fix a Leak into the pool directly above the main drain without the pump running so the product fell directly into the drain.

Could see it slowly being drawn in through the grate. Leak stopped within 24 hours and a week later is still holding. Excellent product.

Had multiple leaks and tried everything to repair it. After using this product iam sold. I instantly saw this product work as I poured it in . Very impressed and highly recommend this product

Had a leak in our hot tub and the pipes are encased in foam insulation so we tried a bottle of Marlig Fix A Leak and voila! It no longer leaks. We followed the directions very carefully and then waited a couple of days to see if the water level would go down before using.

Now we are back to soaking in comfort and enjoying the tub again.

I used to replace my rear view mirror. no other adhesive worked. this did. when I needed to “engineer” a solution for a slightly midsized coupling on the pool filter hose, this worked great. and Never coming off ! When I needed a bracket to hold under the sink, this worked great ! When I needed to reattach a post top in the yard, this worked great ! when I had to repair a crack in the wheelbarrow , this worked great ! When I needed to permanently attach a safety pin into the plug, this worked great ! when I needed to fix a crack in the pool, this worked great ! when I needed to repair an outdoor table leg, this worked great !.

Our 16 year old inground pool started to show signs of wear around the edges. Please keep in mind the only thing I know about pool repair is how to dial a pool contractor who would be happy to charge me hundreds of my hard earned dollars to make a few small repairs.

Luckily, for about the same amount of money I’d spend for a fast food dinner, I found the Leakmaster Epoxy which took five whole minutes to make the repair! Even better, the Leakmaster dries to a off white color which is the same color as the pool edge which blended in beautifully!My kids now think I’m a genius but we’ll keep that little secret between us!.

Works great underwater. Knead well and hold in place for 30 seconds or until it adheres to surface, make sure you wipe any film away from area being treated first before application.

We have a Jacuzzi, Laser hot tub which is known by folks in the business as a “Dinosaur”. As would be the nature of materials used to form it, over its 30 years of existence, things dry up & shrink. Water sealed joints and over-laps [particularly with the skimmers] begin to leak.

If fact, leakage was to such a point that I used 6 mill poly to form a pan underneath the tub which collected the water into a 5 gal bucket. This was after I tried varieties of construction adhesives &/or silicones to stop the 20 gallons of leaking, daily.

After about a year & 1/2, since I used the Boss 802, the tub still doesn’t leak anymore. I’ve kept the 6 mill pan w/ 5 gal bucket & check it whenever to find rain water. Before I calked, I made sure ALL the areas were thoroughly cleaned with rubbing alcohol as a rinse.

Allowing plenty of time to dry, I used the Boss 802, making sure the joints were filled. [no time to skimp!] I waited a full 5 days for curing before refilling the tub; to the top of the skimmers! Great Stuff! I’m purchasing more as I have found it very useful in several other types of applications.

Hot tub began loosing water rapidly. Discovered a leaky filter housing. Removed all the old silicone, cleaned well, applied the Boss 802. Let sit 24 hours since it is submerged in the water. Seems to have done the trick.

No issues since. Easy to work with and tool. Nice product.

I had leaks around my marine speakers and one air control valve, I removed all pieces and laid a bead around each hole. I was able to check for leaks within 10 plus minutes. worked great. prior I tried standard bath and kitchen caulk didn’t work.