583 Formerly Super Thoroseal

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.

Everything was ok.

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.

I used the Thoroseal on the crumbling walls in the basement (cellar), under my very old home. Water would seep in during a hard rain. Since I could do no harm I bought a bucket of the stuff. When it comes the bucket is about half full. I brushed off as much of the loose material from the walls as possible then coated the walls with the Thoroseal. To my surprise it stuck on well. Where I coated the walls there were no signs of moisture. Where water seeps through a painted wall, it will turn yellow. No such appearance occurred. I was using a plastic coffee container to mix the powder with water (the dehumidifier provided ample supply). It worked best if I started with water and mixed in the powder until it was thick enough to stick together, but not so thick that I could not use a paint brush. "pancake batter" thickness works well. I made it thicker for the really rough spots in the wall, it filled the holes and smoothed the wall nicely. It looked good enough that I didn't bother paint over it. I bought two more buckets to finish. No more moisture! As a side note I now have two handy metal 5 gallon buckets. I'm now working on house number 2, with concrete block walls. The Thoroseal leaves the wall a little more rough then I would like, but it takes paint well enough. This is good stuff!

I'm refinishing my inground pool with MS 583. Then I'll paint it. The supplier was great at delivering the product on a timely basis. In fact the various deliveries arrived each time. As far as the product goes, I can't say yet. It is easy to apply but only time will tell how durable it is. I'm hoping to get four years out of it but you never know given the Chicago area winters. When I pull the cover off next spring I'll have a better idea as to this product's durability.

Different name, but same as old Thoroseal.Worked well on fireplace chimney and furnace chimney....looks much better.Remember to water mist all of the project surface before application.

We used this product years ago to seal our basement walls . Time to do it again . Ordered from Amazon , arrived within two days . Excellent product. Very highly recommend.

This works great for our limestone fountain.