Blasting Media - Which Grit Grade??

[Fortunate Son]

Hi there, I have recently taken the plunge and bought a compressor, spot blast gun and will be getting a bench top type blast cabinet soon (if Santa gets his finger out!). Thing is I can't work out which grade aluminium oxide grit to get. I will more than likely be buying from Machine Mart (for convenience) and they sell 60/80 blend, 80/120 blend and 60, 80 and 120 single (malts?!!)

I understand these grades in sandpaper speak, but what do they mean for blasting? I will be blasting fairly light surface rust only as I have cut out anything that has pitted deeply. I also have the facility to re-sieve media as I work in materials testing labs that have sieves - maybe I could buy blended grit and regrade into separate sizes??

Your advice on this one would be much appreciated guys. Cheers in advance, Andy

 

[young_dubya]

Depends what finish you want. the higher the number the smoooooooother the finish. becarefull on alloy parts such as crankcases etc cos they normally use walnut shells or the like to stop the sand making the alloy pourus.

 

[Guest]

i see some nice soda blasters in frosts i was thinking about getting one as ive seen them at work on a few fibreglass boat hulls.