Flex Seal Reviews

I bought Flex Seal to seal a leak in a horizontal aluminum rain gutter seam. I made sure the surface was clean and dry. Initially, I sprayed it three separate times. The seam continued to leak, even after spraying it on four more times. It never did seal the leak, I finally used just black tar roof patch, and that was over two years ago, it still has not leaked. I think Flex Seal products are overpriced worthless products, don't waste your money.

So what I have learned is this stuff should come with directions.

For the spray to work, you have to keep going over it until you get layers! It’s not the best stuff now, the caulking works pretty good for making a rubber seem, but does not like to adhere to some stuff. But it is perfect to make custom seals if they will be screwed down, etc. Now what I did was cut the back of an RV off and extended it and the add-on is wood to aluminum. What I used was the caulking first then I used the tape, the wide stuff, and I went from the sides to the top, and that tape is some strong stuff. Now the liquid stuff does not pour this stuff on, paint it on with a roller, etc. I used it over wood, like some indoor paneling temporarily outside, and painted this paneling with the liquid Flex Seal.. I did two coats of it and man, it gave it a nice rubber texture. When it rained it looked like Rain-X on a window, water was repelling.

The next set of uses are for motor mounts I get. I’m going to use Flex Seal to test them out compared to using 3m window weld.

But yes, I would not use this product to bond anything, and I think it’s good 50% of the time, but it’s expensive for really big jobs. This is for small random stuff, but not like they advertise.

I tried Flex Seal on boots. I applied it to the bottom and at least two inches around the sole. I allowed it to dry over a day. It left the boots feeling sticky and still leaked. I tried it on other shoes with the same result.

My daughter used it to repair chairs, let it dry for a couple of days, but it left them sticky and the black came off on the clothes.

Totally disappointed in this product.

I've tried Flex Seal clear spray twice without ANY sealing.

1. I used it on a little concrete birdbath. I used 3 coats, and it never worked. So I thought that it had to do with concrete.

2. The rain came through little cracks through the brick in my loft. I saw it used on TV for that exact thing...so I thought great, let me try it. NOTHING. Not even on a sliver in the brick. It just came right through.

It absolutely DOES NOT work and is a waste of money. I can't believe their commercials!

The only thing this flexes is your wallet. I first used the Flex Seal spray on a water pan. It lasted a few weeks and water went right through it. I then tried the liquid version, which gave the same results. By its sheer nature, nearly everything advertised on TV is pure junk and way overpriced. This product was no exception. You pay a premium for this stuff to cover the TV ads, but as a waterproof product, it doesn't hold water or just about anything else. First, google any TV product for complaints before buying it. The rule is anything over $20 can be investigated for fraud, so be wary of all those just under $20 items and especially two-for-one offers.

Previous owners had used this product to "seal" a leaking roof air vent, but the problem is, it is all cracking with the heat generated around the aluminum vent and of course the asphalt tiles. I looked along a seam between the Florida room and pool cage, and again this product was cracking and peeling. Sorry, I would not use this product in this environment as it appears it is not suitable in strong, direct, constant sunlight.

I bought this because my pool safety cover was wearing thin on one side and it was letting light through, which allows algae to grow. I figured if it could seal a screen floor of a boat, it will coat the mesh easily. Well, first of all, it is impossible to spread. It's so thick. A paintbrush isn't stiff enough to apply this - it's like tar! I had to brush over the same area multiple times with immense pressure to coat the vinyl mesh, so much so that the paintbrush snapped in half. The blue tape I tried to use to do a neat job was useless and I ended up getting this black tar/paint all over everything, especially me. It didn't coat the fabric either. You can still see through it. In addition, it left a huge black rubber mark on my lawn underneath.

The 32 oz can barely cover the area which was less than the coverage advertised. For $30 it was a waste of money, and I would have been better off buying a gallon of epoxy paint. It would have been cheaper, worked better and much easier to work with.

I used two cans to paint over a 4ft.x 8 inch piece of my rubber dingy to stop a slow leak. No good, I wound up getting some rubber glue and a patch. It worked better and it was much cheaper. Their commercials should be illegal.

I bought a quart of the Flex Seal last summer to fix a leak on the garage lower wall. The prior owner apparently had two idiots build the garage, and they did not grade the concrete away from the wall, so every time it rained hard, the water came in several places. We had the wood repaired along with the siding and lower flashing Several contractors looked at it, and everyone said there was no solution except silicone. Well, I tried silicone, and it never held to the concrete well. I used the quart last summer and it seemed good. After a full summer and a bad winter it was great. The Flex Seal was bonded to the concrete. I bought a gallon this summer and put a three-inch wide layer around and it was great. I give it a 9 out of 10. TV ad items are crap but this item I would give ten stars if I could. Amazed with the result.

Simple repair on a drain pipe (not pressurized) still leaks after two spray cans of this crap. It is not as advertised. There are no negative rating for this rip-off product. It is liquid crap in a spray can.

Don't bother purchasing this product if you are trying to seal a boat fender puncture. On the surface, you would think this product would be ideal for that purpose, but that was not my experience. After locating the pencil-head size puncture to my boat fender, I applied a 2" x 2" piece of Flex Seal (more than adequate for the puncture size) and proceeded to inflate the fender. It inflated beautifully, but (almost immediately) air began to escape from the repaired area. The advertising hype would lead you to believe that this product seals anything and everything. False.