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, Quart
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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, Quart

3.9/5
Product ID: 225321582
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12 interest-free installments with tabby

Details

  • Material
    Rubber
  • Brand
    Flex Paste
  • Style
    3 lb Black
  • Item Weight
    3 Pounds
  • Item dimensions L x W x H
    5 x 4.25 x
💧Waterproof & underwater drying
🖌️Fully paintable finish
🛠️Super thick, fills large gaps

Description

🛡️ Seal it. Paint it. Forget it. The ultimate fix for every crack and crevice.

  • SEAL LIKE A PRO - Creates a flexible, watertight rubberized barrier that blocks air, water, and moisture.
  • PAINT IT YOUR WAY - Once cured, paint over it seamlessly to match any décor or surface color.
  • VERSATILE DURABLE - UV resistant and rust-preventing, perfect for indoor/outdoor, RV, marine, concrete, and more.
  • HEAVY DUTY FILL POWER - Super thick paste clings instantly to fill large cracks, holes, and gaps with ease.
  • UNDERWATER APPLICATION - Unique formula allows application and drying even underwater—no project too wet.

Flex Paste Waterproof Paintable Putty is a premium black rubberized sealant designed to fill large gaps, cracks, and holes across multiple surfaces. Waterproof and UV resistant, it uniquely cures underwater and can be painted over for a flawless finish. Ideal for professional-grade repairs on walls, roofs, RVs, concrete, and more, it locks out air, water, and pests while preventing rust and corrosion. Made in the USA, this 3 lb quart container features a freshness-locking lid to maximize shelf life and minimize waste.

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Specifications

Surface RecommendationWindows,Doors,Tub
Water Resistance LevelWaterproof
Item FormPaste
Compatible MaterialWood, Glass, Tile, Concrete, Aluminum, Metal, Brick, Stucco, Masonry, Copper, Fabric, Fiberglass, Ceramic, Porcelain, Natural Stones, Roofing, Pvc, Eifs, Cspe, Epdm, Hypalon Polyurethanes
Material TypeRubber
ColorBlack
Style Name3 lb Black
Item Weight3 Pounds
Item Dimensions5 x 4.25 x 4.25 inches

Have a Question? See What Others Asked

Could you do several layers or one very thick layer to create a rubberized coating on something?
Any temperature requirement?
Can this be used to fix crack in small ref/frezer
can flex paste be painted ?

Reviews

3.9

All from verified purchases

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.

H**P

Need to work efficiently and minimize product exposure to air.

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?

A**R

Great in clear

Flex seal is a great product. I use it to repair cracks in my stucco outside. Once covered, it does not cracks again. You still need to paint over it because with the clear you can still see the cracks even though they are sealed.

T**N

ease of application

I liked the consistency of the putty. Easy to apply and set up in a time factor that allowed me to work the putty

E**8

It's hard to describe what I think of the product.

In my case, I used it for my purpose. A few days later I wanted to use it again. It was as solid as a rock! I capped it well when I was done with it, but it still setup solid. I liked the way it worked that one time. If I need some again, I'll buy a different kind of container.

E**O

Again, the 2nd bucket purchased had more than 5% paste dried and can't be used.

The first bucket I bought had about 10% paste dried up, and this second bucket had more than 5% paste dried up when opened the container. I think it has to do with the design fault on the container that is unable to seal the moisture. Overall, this product is very expensive, even more expensive after expecting 10% contain loss, and hard to use compared to other similar products. You have to have strong fingers to apply the paste if the tug you bought has dried up.

C**S

Does NOT work as advertised!!!

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.

G**G

Not easy to return

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!!

Common Questions

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Anjali K.

The product quality is outstanding. Exactly what I needed for my work.

1 month ago

Neha S.

Excellent communication throughout the order process. Product is perfect.

2 weeks ago

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Sorry, this item from our KSA store is out of stock. We're restocking soon—check back or contact support for similar products.

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Anjali K.

The product quality is outstanding. Exactly what I needed for my work.

1 month ago

Abdullah B.

Great price for an authentic product. Fast international shipping too!

3 weeks ago

Flex Paste Waterproof Paintable Putty Spackle Sealant Fill Gaps Cracks | Desertcart KSA