Flex PasteWaterproof Paintable Putty, Spackle Sealant, Fill Gaps Cracks Holes - Block Out Water and Air - UV Resistant - Walls, Drywall, EPDM, Concrete, Roof, RV Repairs, Black, Half-Quart

I used this to patch together two pieces of EPDM pond lining. 3 months later it's working beautifully. I also used it to create a 4 inch high stone "wall" for the waterfall to spill over. That also worked very nicely. It does apply well under water [I tested that] but I initially applied it on completely dry lining and dry stones. Left it alone for 3 days just to be sure it cured and there was no disappointment. The only problem was the packaging. I used 2 containers and each was only half useable. The middle of the paste was pliable but somehow the outer rims of paste were too hardened to use. Basically, between the 2 containers, I was only able to use what amounted to 1 container. Other than that, I'll be using this paste again. It's very strong, really seals, and lives up to all the claims.

Very disappointing. I had my project all prepped and then when I open the can it was hard as a rock. Now I have to return it and wait for another. Frustrating!

My property came with a very old and very leaky shed. First, I tried putting duct tape over the various sized holes (it didn’t work very well!) I then went to the internet to find a product that other people recommend - and found this! It’s super easy to apply, stopped up the holes, and has lasted (at this for a few weeks) with no signs of breaking down.

Product worked very well. Good amount of workable time, spreads well with a small spackling knife.The only complaint is that the product arrived with the top 1/8" dried up and unusable, and since you don't get that much in the can, having to throw away about 2 spoons full is a real problem. They need to seal the can lid better.

was disappointed in this product. Managed to get enough for project by digging into center ofjar. around the sides of the jar the product was hard as rocks..not usable.

I was painting my dingy old basement and make it a little more inviting to do my laundry when I notices the concrete steps I had painted two days before with a sealant paint had white water marks. I realized the threshold outside the door had a crack underneath and the water was running behind the stairs. I used this product on the area and repainted the stairs and now I have no more water leaking in! Great product and works as advertised.

I ordered this to help seal up some areas of my newly purchased old house. I bought it 2/14/25. I opened it today 4/14/25 to start sealing up a few places in the attic. It was crusted over on the top so I peeled the top off and used the goo underneath that was still plyable. It worked OK. WARNING: YOU WILL NEED MINERAL SPIRITS FOR CLEAN UP! I don't mind a bit of mess, but it was crazy trying to clean this off the pallet knives and excess on the areas.Because it's past the 30 days since purchase, I have no recourse. So disappointed!!

Unfortunately the top half of the paste was already hardened when we first opened it. So it was nearly unusable. The was some at the bottom of the jar that was salvageable.