From another thread about dust collecting.
I was told that glass bead is not the best media to use when cleaning parts as it will create a smooth surface. Obviously this is not ideal as the powder has nothing to grab hold off.
I do a mixture of cast aluminum (intake manifolds, timing covers, throttle bodies, etc..) and also steel (pulleys, starter casing, alternator casing, brackets, etc..). Would black beauty/black diamond be safe for both of these metals? Also would the heavier grain be more idea? http://www.tractorsupply.com/tools/sandblasting-tools-accessories/sandblaster-abrasive-blasting-grit-20-40-50-lbs-3905403
thanks again for all the help