If you have a nice blast cabinet already, just too small, get some 3/4" or 1 " square tube and some sheets of 14 gauge and make extensions. I would angle the floor of the extensions (a left one and a right one so you have blasting in the center). The angle would be so that the sand can migrate down into the feed. I guess the reason I haven't addressed this issue is because of the nature of the dust. It needs to be tight. That means it would be pretty hard to cobble something together that doesn't leak. I guess when I DO address it, it would be a permanent solution involving welding. This is when I wish I lived in south Texas or somewhere with a really nice climate. I could just make it for outside use and be done with it.
