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💪 Seal it. Paint it. Forget it. The ultimate fix for every crack and crevice.
Flex Paste is a premium 3 lb black rubberized putty designed for professional-grade sealing and repairs. Waterproof and UV resistant, it forms a flexible barrier that blocks air, water, and moisture, even curing underwater. Its thick consistency fills large gaps and cracks instantly, while the airtight container ensures long-lasting freshness. Fully paintable and compatible with a wide range of materials, Flex Paste is the go-to solution for walls, roofs, RVs, concrete, and more—delivering durable, clean, and customizable repairs made in the USA.












| ASIN | B084TDDCWW |
| Best Sellers Rank | #8,672 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #31 in Hardware Sealers |
| Brand | Flex Paste |
| Brand Name | Flex Paste |
| Color | Black |
| Compatible Material | Wood, Glass, Tile, Concrete, Aluminum, Metal, Brick, Stucco, Masonry, Copper, Fabric, Fiberglass, Ceramic, Porcelain, Natural Stones, Roofing, Pvc, Eifs, Cspe, Epdm, Hypalon Polyurethanes |
| Customer Reviews | 4.0 out of 5 stars 6,015 Reviews |
| Included Components | Household Item |
| Item Dimensions | 5 x 4.25 x 4.25 inches |
| Item Form | Paste |
| Item Type Name | Flex Paste 3 lb Tub (Black) |
| Item Weight | 3 Pounds |
| Item dimensions L x W x H | 5 x 4.25 x 4.25 inches |
| Manufacturer | Swift Response, LLC |
| Material | Rubber |
| Material Type | Rubber |
| Model | FLEX SEAL - PFSBLKR32 - BLACK |
| Number of Items | 1 |
| Part Number | PFSBLKR32 |
| Style | 3 lb Black |
| Style Name | 3 lb Black |
| Surface Recommendation | Windows,Doors,Tub |
| UPC | 850010226811 |
| Unit Count | 48.0 Ounce |
| Warranty Description | 1 Year Limited |
| Water Resistance Level | Waterproof |
F**S
Perfect water sealant with no leaks on cracked items
I had an outdoor water fountain that I forgot had water in it and it froze.... Which made the whole fixture crack at the water expanded. I use this flex paint to see if it would be able to seal the cracks and hold the water and it did!!! No more leaks and i the adhesion holds really really well. Drives fairly quickly like maybe 24 hours. The smell is a little strong so I would let it sit outside as it dries.
L**K
Good stuff, simple to use
I was worried bjt, it worked I repaired a fiberglass bathtub, it was thick, I globed it on and to worked good, my can was air tight and fresh, not permanent but long lasting patch, don't get it on your clothes,,,
B**N
Works under any condition
I want to rate this product lower because this is the second one I’ve bought that had a hard 2/3” top so 10-15% of it is trash. This product is also very hard to work with. This will not spread smooth and is very messy. This product will only patch a small area. I used the entire tub for this small patch over. However, I am rating this product a 4 star because there is not another product that I know of like it. This is the second time patching my rooftop tent due to the tent getting a crack in it. This product went on and cured in the very moist fog. It then rained and still cured. This product lasted through a very cold winter through heavy snow and some rain. This product took abuse from heavy 4x4ing and flexing. It wasn’t until it was well over 100f and with some flexing this product split. I bought this second tub to patch the crack.
K**G
Arrived Bone Dry...Twice!
Purchased this product, material was bone dry in the can, hard as a rock… I did a return, same thing, hard as a rock bone drive. Both of the cans were completely sealed and had no dents on the top so it doesn't look like they had been resealed so I'm guessing this is a problem, maybe with the Black? Which is what I use. Anyway, whoever, however, whatever, this is pretty crappy
T**L
Easy to Use and Excellent Waterproofer
We have a large deck storage box for outdoor seat cushions, and squirrels soon used the edges of the box lid to sharpen their teeth; thus, destroying the waterproofing of the box. First, I had to get rid of the squirrels, and I finally adopted some outdoor cats to make the squirrels move to the treetops, where the little rodents sharpen their teeth on tree branches instead of on my deck box and outdoor furniture. Second, I had to repair an expensive deck box, and the answer was Flex Paste, which I applied with a putty knife. It was easy to apply and shape--initially to seal the gaps and form a rounded corner, and later to fill the right angle edge that I formed with the corner of a cardboard box. I was not looking for beauty; instead I went for utility. After all, it's just a deck storage box. I wore disposable rubber gloves during the project, and I used paper towels and 90 percent rubbing alcohol to clean my putty knife and pocket knife afterwards. I finished the job yesterday and a heavy thunderstorm rolled in today. I just checked the repaired box, and our seat cushions are perfectly dry. Mission accomplished!
F**T
Ordered the "Stay Fresh" can, received the plastic tub
Amazon's web page shows the "NEW! Stay Fresh Container", but they shipped the old obsolete plastic tub. As many of the other reviewers have correctly stated, the plastic tub cannot keep the product soft, pliable and usable. I called the FlexSeal factory, and they are fully aware of the problem. If you order from the FlexSeal website, the factory is shipping the Stay Fresh can as of 2024, March 12. This is a good product, but it's a complete waste of money to buy it in the obsolete plastic tub. That form of packaging is incapable of keeping the product in usable form. It hardens from the top down. I bought two from local stores, and learned that if you squeeze the tub at the top and it doesn't feel soft, the product has hardened and won't be usable. Typically it will be softer near the bottom, but all of the product above (the unsqueezable part) is so hard you can't get it onto the putty knife. Amazon needs to stop shipping the product in the obsolete plastic tub. Update: I called Amazon Customer Service and advised them that the plastic tub packaging is obsolete and no longer being shipped by the factory, and that they should return all product in the plastic tubs, and ship only the product (in the can) shown on the web page. I was advised that they would do so. That was on March 16, the same day I ordered the new (can) packaging directly from the factory. It arrives today (March 20). Shipping was free. Looking forward to seeing how it performs in patching a stucco parapet wall. Update: I received the can from the factory. The product was fresh and easy to apply. Because I was applying it on stucco, it took more to fill all the nooks and crannies than I expected, so I will need another can to finish the job. I ended up doing the whole job with a putty knife. I applied it in full sunlight on a warm breezy day, but it stayed flexible enough to work it into a smooth surface as I went. I doubt it will need a second coat. I don't know how long it will last, but I expect it will be pretty durable. There is no way any rain is going to get through the FlexPaste. I used a rubber spatula to scrape all the product from the sides and bottom of the can. Clean-up was easy; I just wiped the material off the tools with paper towels.
B**Y
It really works!
This is an a-m-a-z-i-n-g product!!! I stumbled on a small can of it in a hardware store. It works so well, that I purchased a gallon. I am using it on the roof of my motor coach and a box trailer.
C**E
Tough stuff!
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.
F**T
loved it
fixed the problem we had
J**S
Good
Fast
G**S
Excelente !!
Excelente producto, hace todo lo que promete. Solo lo puedes usar una vez, lo deje muy bien tapado como venía en el instructivo y se seco, pero cumple perfectamente su función.
G**N
Great filler.
Very handy gap filler provides great flexibility.
関**雄
半分は固まり
トップライトの雨漏りに、ガラス周りをこのペーストでシーリングしました。効果は高いけど購入の半分は固まりで使えない
Trustpilot
1 day ago
3 weeks ago