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

  • Based on 5,784 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon

Arrives Sunday, Nov 2
Order within 18 hours and 55 minutes
Available payment plans shown during checkout

Color: Black


Size: MAX


Features

  • NEW! STAY FRESH CONTAINER Blocks out air and locks in freshness to extend the sealing power of Flex Paste, with no waste
  • COAT, SEAL & PROTECT - Penetrates deep to seal out air, water, and moisture. Once dry, it turns into a strong, flexible, watertight, rubberized barrier
  • WORKS UNDERWATER - Can be applied underwater, and it even dries underwater
  • FILLS LARGE AREAS - Super thick rubber paste clings to the surface and instantly fills large gaps, cracks, and holes
  • FULLY PAINTABLE - Once fully cured, it can be painted any color. Helps prevent rust and corrosion, and it is UV resistant
  • EXCELLENT FOR filling cracks and holes, foundation and concrete repairs, bath and shower, indoor and outdoor projects, roof, RV, motorhome, auto, marine, lawn and garden projects, DIY, hobbies, and more
  • MADE IN THE USA

Material: Rubber


Brand: Flex Paste


Style: 12 lb Black


Item Weight: 12 Pounds


Item dimensions L x W x H: 7.75 x 6.75 x 6.75 inches


Product Dimensions ‏ : ‎ 7.75 x 6.75 x 6.75 inches; 12 Pounds


Item model number ‏ : ‎ PFSMAXBLK01


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ August 11, 2021


Manufacturer ‏ : ‎ Swift Response, LLC


Best Sellers Rank: #6,941 in Tools & Home Improvement (See Top 100 in Tools & Home Improvement) #21 in Hardware Sealers


#21 in Hardware Sealers:


Customer Reviews: 3.9 3.9 out of 5 stars 5,784 ratings


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Nov 2

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Need to work efficiently and minimize product exposure to air.
Color: Black Size: MAX
Used it to fill in around, and cover; previously tar-filled expansion joints on a concrete driveway. It went on relatively smoothly until exposure to air began setting the contents while working with it and it became relatively lumpy and difficult to continue applying. I may brush the liquid over the paste later in a concerted effort to smooth the application? I may also try to smooth it with a wire wheel on my Ryobi string trimmer? ... show more
Reviewed in the United States on June 13, 2025 by HiDolPmPpp

  • Good stuff, simple to use
Color: White Size: Half-Quart
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,,,
Reviewed in the United States on April 18, 2025 by Luckyduck

  • Does NOT work as advertised!!!
Color: White Size: Half-Quart
UPDATE - I have been monitoring the pipe for the last few days. While I initially thought the paste was going to provide the fix I needed, that "thought" would be incorrect. The water started leaking again. Be smart/save your money and do not buy this stuff. I'm going back to what I should have done to start with - turn off the water and replace the pipe. This Flex Paste is JUNK!!!! Had a very small leak at the base of this water faucet (small droplets of water on the PVC surface). Based on the advertisement I thought the paste would be the perfect fix. I followed the directions as stated on the container. After apply a good initial coat, I still had the small leak. The next day, I applied another coat - still had the leak. The next day, after turning off the water to everything, I applied another coat heavy/massive amount of paste using both a putty knife and my hand. Left the water off for 1 to 2 hours and the leak appears to have stopped (after using most of the paste). What a pain!!! While using the paste, I was diligent in keeping the lid on the paste. At the end of each day, I would use a rubber mallet to hammer the lid on. Regardless of the tight seal, the paste still hardened. Probably would have been easier to just replace the bad piece of PVC that was leaking. ... show more
Reviewed in the United States on October 28, 2024 by Carroll S Carroll S

  • Works under any condition
Color: Black Size: Half-Quart
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. ... show more
Reviewed in the United States on September 16, 2024 by Bman Bman

  • Great option
Color: White Size: Half-Quart
Just used this on my laundry room floor where I’ve been having some water issues from my washer. So far so good. This was easy to put on and sticks well to ceramic tile. I would use this item wherever I have need.
Reviewed in the United States on August 23, 2025 by P3

  • Ordered the "Stay Fresh" can, received the plastic tub
Color: White Size: Quart
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. ... show more
Reviewed in the United States on March 16, 2024 by Fezno Mint

  • Product great delivery not so
Color: White Size: Half-Quart
Product is great but delivery service is absolutely terrible! They say that you're the next stop and then they have like six other places to go before they deliver
Reviewed in the United States on September 2, 2025 by reviewmaster

  • Great stuff
Color: White Size: Half-Quart
Love flex paste. Use it a lot.
Reviewed in the United States on August 19, 2025 by Mike

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