Perma Pool Patch 50 lbs Fast-Setting, High-Strength Mortar - White This strong, fast-setting white cement is specially made for under water use, but works just as effectively in out-of-water applications. The beauty of this easy to use product is being able patch your concrete pool without having to drain it. Added to that is the fact that Perma Pool Patch is twice as strong as ordinary cement, and has 3 times the bonding power. It will bond to old or new concrete, as well as masonry, metal, etc. You can add various colors to achieve desired appearance. Just add water and apply.