Sandblasting Marblesheen and Concrete
Sand (Abrasive) blasting is often used as an ideal way to prepare a pool before painting. Done well it removes all loose material and provides a good key to paint onto. This usually applies to concrete surfaces, which may have been painted with epoxy or more often chlorinated rubber.
However sometimes blasting has been attempted on softer surfaces like Marblesheen. The result can easily be seen in the pictures. Don’t do it. Even on concrete a poorly done job can look like this too, so make sure the blaster knows what he is doing.