How To Sand Concrete Countertops. We think ours cracked because the weather was ‘warm’ for winter and then got rapidly cold as it was drying. Three days after pouring a counter with countertop mix, the compressive strength of the slab will achieve resistance equal to 2,000 pounds per square inch (psi).
Keep the polisher level as you go to keep the surface even. For a countertop, just sand for about 45 seconds, then clean the surface and check it out. This slurry can be about the texture of pancake batter.
That’s right it’s called concrete sand.
Concrete does crack while drying for a variety of reasons. This formula for wet cast makes about 1 cu. That’s right it’s called concrete sand. One of the most alluring features of concrete countertops is that they are crafted by an artisan rather than mass produced in a factory.