[cdowns]

playground sand is a very poor choice. it is tumbled for smoothness and doesnt cut well in blasting. blasting sand has sharp edges and cuts very good when blasting. plus alot of playground sand has higher moisture content causeing poor blasting performance. then theres the worry of where it is mined and if there is salt content in some playground sand
i've found generally those cheap siphon blasters marginal at best, nothing like a pressurized unit.
water filtration is oof the utmost importance blasting air must b dry

when blasting full skin and eye protection is a must as well as good respirator