While im no expert i will add my 2 cents worth.I used a cheap siphion model and to some degree was able to controll the intensity by adjusting the air presure.Iused both silica sand and and a black comercial blast material.Ihad no problem with the silica sand clogging but the comercial stuff seemed to work a lot better.it had a more jaged edge and hurt more in the eyes than the sand l.o.l Wich brings me to my next point.How ever much you spend on the gun,dont scrimp on the safty gear.