--- product_id: 5073934 title: "MasterSeal 583 Formerly Super Thoroseal" brand: "masterseal" price: "44284 kr" currency: ISK in_stock: true reviews_count: 8 category: "Master Seal" url: https://www.desertcart.is/products/5073934-masterseal-583-formerly-super-thoroseal store_origin: IS region: Iceland --- # 100% waterproof seal Harder than concrete Made in USA quality MasterSeal 583 Formerly Super Thoroseal **Brand:** masterseal **Price:** 44284 kr **Availability:** ✅ In Stock ## Summary > 💧 Seal it once, protect it forever! ## Quick Answers - **What is this?** MasterSeal 583 Formerly Super Thoroseal by masterseal - **How much does it cost?** 44284 kr with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.is](https://www.desertcart.is/products/5073934-masterseal-583-formerly-super-thoroseal) ## Best For - masterseal enthusiasts ## Why This Product - Trusted masterseal brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Proudly American:** Manufactured in the USA, ensuring premium quality standards - • **Trusted Longevity:** Proven performance with 16+ years of waterproofing success - • **Unmatched Durability:** Harder than the wall itself for long-lasting protection - • **Effortless Application:** Dry powder form—just add water and apply with ease - • **Superior Waterproofing:** Seals pores and voids to block every drop of water ## Overview MasterSeal 583 is a heavy-duty, cement-based waterproof coating designed for concrete and masonry surfaces. Harder than the substrate itself, it fills pores and voids to provide a complete water barrier. Supplied as a dry powder for easy mixing and application, this USA-made product delivers proven, long-lasting protection ideal for demanding outdoor projects. ## Description MasterSeal 583 Formerly Super Thoroseal Waterproof Coating Not a paint, a heavy, cement base waterproof coating for concrete or masonry Harder than the wall itself Fills and seals pores and voids, assures complete protection against water penetration Dry powder form, just add water White 5 gallons. This Product is manufactured in United States. Review: This stuff really works! - 16 years ago, we used this product (then called Thoroseal) to waterproof our above-ground 800-gallon fish pond. I am very impressed with the longevity of the product to date, so I bought it again when the concrete needed to be re-plastered. The second go round required much more preparation than the first (as expected), since 16 years of embedded algae and dirt needed to be removed with a brush, pressure washing with mild soap, rinsing, and several repetitions. The fish and plants were kept in a stock tank (large water trough) while the prep work and application were performed. I think a small plastic swimming pool would work too for keeping your plants alive and the goldfish, if they're small. Doing this project in temps in excess of 105° in south central Texas made applying the plaster a bit challenging. It dries quickly, so we used a sprayer bottle with water spritzing to keep the product moist enough to spread it. In retrospect, I think thinning it a bit more to begin with and applying thinner coats would have been easier and more effective. The heat was a complicated matter. Overall, the size of your project will determine ease of use. The smoother your surface, the easier it will be to apply. I consider my pond project more difficult than most coz it's a rough, hand-poured concrete structure with lots of bumps and dips and some tiny cracks. The pond looks good and the fish are happy, so I call it an overall success. Will definitely use this product again for outdoor concrete waterproofing. Review: Great water sealers - If you want to guarantee no water intrusion then buy this product. Easy to apply and not too expensive for the great result ## Features - MasterSeal 583 Formerly Super Thoroseal Waterproof Coating - Harder than the wall itself - This Product is manufactured in United States ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000BO9U8S | | Batteries Included? | No | | Batteries Required? | No | | Best Sellers Rank | #180,826 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #495 in Wall Surface Repair Products | | Color | No Color | | Customer Reviews | 4.6 4.6 out of 5 stars (198) | | Date First Available | February 17, 2007 | | Included Components | Hardware; Door, Gate & Window Hardware;weatherproofing-window-insulation-kits | | Is Discontinued By Manufacturer | No | | Item Package Quantity | 1 | | Item Weight | 39 pounds | | Item model number | T5010 | | Manufacturer | PRIMESOURCE PNEUMAT | | Material | Plastic | | Part Number | T5010 WHT | | Product Dimensions | 22 x 7 x 7 inches | | Size | No Size | | Style | Compact | | Warranty Description | Warranty | ## Images ![MasterSeal 583 Formerly Super Thoroseal - Image 1](https://m.media-amazon.com/images/I/51XPrEdQwES.jpg) ## Questions & Answers **Q: Will thiw product work as a coating for swimming pool** A: Trufully it can. BUT, be aware that it will not work effectively seal any cracks not even hairline in an underwater situation. If using as a decorative coating shouldn't be a problem, Also keep in mind, manufacturer will not warranty this application **Q: Will this work inside a cistern where it will be constantly submerged?** A: According to Thoro - THOROSEAL is not suitable for retaining water with a low calcium hardness and/or a pH of less than 7,2 (THOROSEAL FX100 may be used for this application).Nor is suitable for application to horizontal surfaces that are subject to freeze/thaw cycles or vehicular traffic.If THOROSEAL is used to waterproof a potable water reservoir, a swimming pool or a fish tank, it should be washed down after the curing completed with a saline solution (salt brine), 12,5% of salts in water, and thoroughly rinsed with clean water. This process should be repeated until the required pH conditions are obtained. That said, I am applying it to the interior of concrete cistern tanks I am building, without the salt brine rinse. Rainwater is slightly acidic (under 7 pH). So I added some washed limestone rocks to the tanks. **Q: Can i use this product to reduce radon gas levels? i am currently at 4.7pcl with two active soil suction systems.** A: I used it to seal/plug floor cracks and holes and my radon levels improved. **Q: Thoroseal Waterproofing Paint. IS IT 3 PARTS WATER TO 1 PART POWDER?** A: how can I color it ? for use on exterior below grade cinder block ? do not want white or black, because some block will be above grade...and the wife says so... ## Customer Reviews ### ⭐⭐⭐⭐⭐ This stuff really works! *by D***E on September 19, 2023* 16 years ago, we used this product (then called Thoroseal) to waterproof our above-ground 800-gallon fish pond. I am very impressed with the longevity of the product to date, so I bought it again when the concrete needed to be re-plastered. The second go round required much more preparation than the first (as expected), since 16 years of embedded algae and dirt needed to be removed with a brush, pressure washing with mild soap, rinsing, and several repetitions. The fish and plants were kept in a stock tank (large water trough) while the prep work and application were performed. I think a small plastic swimming pool would work too for keeping your plants alive and the goldfish, if they're small. Doing this project in temps in excess of 105° in south central Texas made applying the plaster a bit challenging. It dries quickly, so we used a sprayer bottle with water spritzing to keep the product moist enough to spread it. In retrospect, I think thinning it a bit more to begin with and applying thinner coats would have been easier and more effective. The heat was a complicated matter. Overall, the size of your project will determine ease of use. The smoother your surface, the easier it will be to apply. I consider my pond project more difficult than most coz it's a rough, hand-poured concrete structure with lots of bumps and dips and some tiny cracks. The pond looks good and the fish are happy, so I call it an overall success. Will definitely use this product again for outdoor concrete waterproofing. ### ⭐⭐⭐⭐⭐ Great water sealers *by P***G on April 12, 2024* If you want to guarantee no water intrusion then buy this product. Easy to apply and not too expensive for the great result ### ⭐⭐⭐⭐⭐ Nice Finish! *by J***H on July 3, 2025* I have used Master Seal since way back when it was called ThoroSeal. It has never failed me. I’ve used it on my foundation and on my stucco front porch. It is really meant for unfinished surfaces but I have cheated and used it on old painted surfaces without any ill effect so long as any flaking paint is scraped off. The directions call for 5 1/2 quarts of water and that is spot on. You get a nice consistency that is easy to spread. The longer it takes to finish the job though you will probably need to add a bit of water as you go. Mixing it can be difficult and time consuming so it’s worth the money to purchase a stirring attachment for a hand drill. It makes it so much easier than mixing with a large paint stick. Mixing with a stick will take at least an hour and you’ll end up with large clumps of undissolved material at the bottom of the pail. The drill attachment is much cleaner and faster. ## Frequently Bought Together - MasterSeal 583 Formerly Super Thoroseal - Thoro T1669, 1 Gallon - DQB Industries 11943 Dqb Masonry Brush, 6-1/2 in L, Tampico Colored Poly/Synthetic Bristle Trim, 6-1/2In --- ## 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.is/products/5073934-masterseal-583-formerly-super-thoroseal](https://www.desertcart.is/products/5073934-masterseal-583-formerly-super-thoroseal) --- *Product available on Desertcart Iceland* *Store origin: IS* *Last updated: 2026-04-27*