What is a common problem that sandcarvers face?

Blasting too many different substrates like bricks and glass in the same cabinet can cause quite a few problems. Try to keep these substrates separate, as brick particles that have been blasted away will contaminate the abrasive and lead to craters occurring when you etch on glass. You can use two different cabinets or you can use a tent screen or silk screen to help contain the particles. 

   —IKONICS Imaging