I have that very same blaster it works fair at best, however to get it set correctly is PITA and you get sand everywhere. I went through alot of Silica sand ended up beating the heck out of me with the sand and not much rust off. it works best when you first start when the sand is just coming to the tip and at the end when the sand runs out of it. I have a large 120 gal 5HP twin cyl Air compressor so air was not the problem. The valves on the blaster just won't adjust correctly. it took me three bags of sand to do a two foot square.
I was thinking of upgrading to this one for a little more money. plus there is a Granger near me. My neighbor had one of these and it seemed to work better.
Just my opinion someone else may have had better luck with it