--- product_id: 208933842 title: "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, White, Quart" brand: "flex paste" price: "£43.69" currency: GBP in_stock: true reviews_count: 13 category: "Flex Paste" url: https://www.desertcart.co.uk/products/208933842-flex-paste-waterproof-paintable-putty-spackle-sealant-fill-gaps-cracks store_origin: GB region: United Kingdom --- # Fully paintable & UV resistant Waterproof & dries underwater 3 lb super thick rubber paste 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, White, Quart **Brand:** flex paste **Price:** £43.69 **Availability:** ✅ In Stock ## Summary > 🔧 Seal it. Paint it. Forget it. The ultimate fix for every crack and crevice. ## Quick Answers - **What is this?** 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, White, Quart by flex paste - **How much does it cost?** £43.69 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/208933842-flex-paste-waterproof-paintable-putty-spackle-sealant-fill-gaps-cracks) ## Best For - flex paste enthusiasts ## Why This Product - Trusted flex paste brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Seal Like a Pro:** Creates a flexible, watertight rubberized barrier that blocks air, water, and moisture. - • **Versatile Fixer:** Perfect for walls, roofs, RVs, concrete, and more—your all-in-one gap, crack, and hole solution. - • **Paint It Your Way:** Once cured, paint over it seamlessly to match any surface or décor with UV protection. - • **Freshness Locked In:** Innovative airtight container keeps your paste fresh and ready, eliminating waste. - • **Underwater Application:** Unique formula allows application and curing even underwater—no job too tough. ## Overview Flex Paste is a premium 3 lb waterproof, paintable rubberized putty designed to fill large gaps, cracks, and holes across multiple surfaces. Its airtight container preserves freshness, while its unique formula works underwater and cures into a flexible, UV-resistant seal. Ideal for indoor and outdoor repairs on walls, roofs, RVs, concrete, and more, it offers a durable, paintable finish that blocks air, water, and pests, making it a must-have for professional-grade DIY and maintenance projects. ## Description Product description Works indoors and outdoors. Penetrates deep to seal out air, water, and moisture. Once dry, it turns into a strong, flexible, watertight, rubberized barrier. Apply to almost any surface. Use on: Wood, glass, tile, concrete, aluminum, metal, brick, stucco, masonry, PVC and so much more. Clings to wet and dry surfaces. Even underwater. No need to wait for surfaces to completely dry before sealing them. It even cures underwater. Can be spread, shaped, and formed. This thick rubberized paste is exceptional for all types of crafts, hobbies, and more. Won’t shrink, crack, or become brittle. Flex Paste stays completely flexible, making it perfect for all-season roof repairs and all types of DIY projects. Made in the USA Flex Paste is proudly made in America, using globally sourced products. DIRECTIONS Using putty knife, trowel or similar tool, remove an even layer from the top surface. Do not scoop deeply into the tub as this may create air pockets. Apply a generous amount to the surface using a smooth motion. Always make sure all cracks & holes have been completely filled & cured before testing. Review: 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. Review: 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,,, ## 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, sealing out rodents and pests, bath and shower, indoor and outdoor projects, roof, RV, motorhome, auto, marine, lawn and garden projects, DIY, hobbies, and more - MADE IN THE USA ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0851N5CGM | | Best Sellers Rank | #10,098 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #34 in Hardware Sealers | | Brand | Flex Paste | | Brand Name | Flex Paste | | Color | White | | 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 6,016 Reviews | | Included Components | Item | | Item Dimensions | 5 x 4.25 x 4.25 inches | | Item Form | Paste | | Item Type Name | Flex Paste PFSWHTR32 3 Lb. Tub - White | | 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 | PFSWHTR32 | | Number of Items | 1 | | Part Number | PFSWHTR32 | | Style | 3 lb White | | Style Name | 3 lb White | | Supported Standards | ASTM C-920 | | Surface Recommendation | Doors,Tub | | UPC | 850010226842 | | Unit Count | 48.0 Ounce | | Warranty Description | 1 Year Limited | | Water Resistance Level | Waterproof | ## Product Details - **Brand:** Flex Paste - **Item Weight:** 3 Pounds - **Item dimensions L x W x H:** 5 x 4.25 x 4.25 inches - **Material:** Rubber - **Style:** 3 lb White ## Images ![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, White, Quart - Image 1](https://m.media-amazon.com/images/I/51DCxc-BmoL.jpg) ![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, White, Quart - Image 2](https://m.media-amazon.com/images/I/71id8yOrn8L.jpg) ![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, White, Quart - Image 3](https://m.media-amazon.com/images/I/71yd+Gnyk+L.jpg) ![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, White, Quart - Image 4](https://m.media-amazon.com/images/I/71xvXuxwrIL.jpg) ![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, White, Quart - Image 5](https://m.media-amazon.com/images/I/71mAPcut5pL.jpg) ## Available Options This product comes in different **Color, Size** options. ## Questions & Answers **Q: Could you do several layers or one very thick layer to create a rubberized coating on something?** A: Absolutely, just please remember that the thicker the final coating is, the longer the cure time will be. We highly advise creating the coating by adding layers to the surface rather than just one thick coat. **Q: Any temperature requirement?** A: Flex Paste can be applied in a wide range of temperatures from 0°F – 150ۜ°F. Once applied and fully cured it can withstand a wider range of temperatures from -40°F – 200°F. **Q: Can this be used to fix crack in small ref/frezer** A: Hi there. Thank you so much for reaching out. Flex Paste can withstand low temps like that in a freezer. Although some customers have found success with similar applications, it has not been tested for its safety when coming in contact with items used for food preparation, storing, or serving. Please contact us if you have any additional questions. We're always happy to help. Flex On! **Q: can flex paste be painted ?** A: Yes. Must be fully cured before painting. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Perfect water sealant with no leaks on cracked items *by F***S on December 13, 2025* 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. ### ⭐⭐⭐⭐⭐ Good stuff, simple to use *by L***K on April 18, 2025* 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,,, ### ⭐⭐⭐⭐ Works under any condition *by B***N on September 16, 2024* 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. ## Frequently Bought Together - 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, White, Quart - Flex Caulk, Waterproof & Weatherproof Hybrid Polymer Sealant, Strong, Paintable, Indoor, Outdoor, Bath, Shower, Sink, Window, Baseboards, Door, RV, Roof, Wood, Auto & Marine, White, 9 oz, 1-Pack - Flex Seal Liquid, 1 Gallon, White, Liquid Rubber Coating Sealant, Waterproof, Flexible, Breathable, and UV Resistant, Roof Repair, Basements, RV, Campers, Trailers, Marine, EPDM, Masonry --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/208933842-flex-paste-waterproof-paintable-putty-spackle-sealant-fill-gaps-cracks](https://www.desertcart.co.uk/products/208933842-flex-paste-waterproof-paintable-putty-spackle-sealant-fill-gaps-cracks) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-19*