I went to toys r us or home depot and bought bags of play sand. Its a refined sand for kids to play in. Its a bit coarse at first in the blaster but it pulverizes as you use it and recycle it. My cabinet is home made out of wood. I took a craftsman sandblaster and placed it under the structure with a gasket seal so the sand falls back in through a screen for filtering. It clogs in the gun with moisture every now and then. I only use it on rare occasion now. Actually I stand corrected. I did use it on the MG gasser headlight buckets. It did a great job on a lot of old iron stuff from the coupe.
Hope yours works well for you.