Do you know what it is called when the people come to your house and clean the white s off the side of.....

Lime or calcium deposits can be removed with muriatic acid, sand blasting seems like overkill. Sand and bead blasting can use many different abrasives and pressures. Everything from beach sand, diamonds, gl beads, steel shot and even corn cobs. Pressures from 50-150 are common, higher pressures usually use fluids like oil and water instead of air. RScott