Best setup is a dust separator. ***** the dust without sucking the heavier grit. Sand is for sand blasing houses for repaint or other uses. Sand shouldn't be used for metal parts unless it's been dried. Grit is what you want to use in a grit blast cabinet for metal parts. Aluminum Oxide, Glass bead, Carbide, Walnut shells, ect. The is a ton of different types of blasing medie, but sand isn't very effiecient for metal parts. You need sharp edges where as sand has none. It's the velocity that makes it work. Grit cuts because of it's sharp edges.
Last machine shop I worked at was a thermal coating company, I was machine shop lead machinist and shop lead. We had 14 grit blast cabinets of varying sizes up to and including a walk in. We used every kind of grit you can get. All but a couple cabinets had timers spicifically for grit wear. The cabinet pressure would shut off and could not be turned back on without new grit being put in and the timer reset by a manager. That guaranteed clean efficient cutting grit at all times. We had specs to meet regarding surface roughness before for thermal spray coatings.
Coating for the aerospace and aircraft industry, you name it, any and all industries. But manily aerospace and aircraft. Good yet fairly affordable grit is Aluminum Oxide. Holds up fairly well for a while under regular daily use. Higher pressure does break down grit faster but cuts faster too. Its a trade off of course. Carbide grit cuts and last a long time, but is not cheap. Glass beas is for delicate blasting and minimum surface deterioration and wont heat part surface as much as more agressive grit. The angle of blast effects wear. Straight direct blasting cuts good but wears grit faster. Angle the flow for less wear while still cutting good. There is more to grit blasting then you would think. You can combine grit too for different cutting action.
Some grit you do not want to use on certain types of materials. Will heat part surface, can cause warping and can imbed in the parent material causing issues. At least for thermal spray applications and painting and other reasons.
