Can someone advise what the best media to use in my new (Christmas present) bench top blast cabinet, for use in removing rust from old parts? It appears that glass beads would be the best all around media? And will a moisture trap installed in the compressed air line do an adequate job of removing crud from the supply line air?
Glass beads will work if the surface is not rusted really bad. You may want to also get a bag of aluminum oxide which would cut faster than glass when removing heavy rust.
Moisture trap should be mounted as far away from the compressor as possible, should be at the cabinet.
How well it works depends on you're conditions, here in Oklahoma we have high humidity and I find a three stage filter works best for me. Check out La-Man extractor dryers, a bit pricey, but well worth the $$$ IMO.
Correction the La-man dryer is a two stage filter. Sorry.
I use ground glass for quick removal and then if it needs a smooth finish I follow with fine glass bead. Think of it like sand paper. Start with something coarse them move to finer. Otherwise you will just be spending lots of time. The other thing is keep the pressure relatively low, 40 to 45 pounds. Higher pressures just blast your media in to dust.
In any media blaster whether its sand, glass beads, or etc, humidity is what usually will cause you problems.
I use the finest sand I can get here in town. Its no.9.
Its cheaper than glass beads. I first strain the sand using screen wire over a 5 gal. bucket.
When that's done there usually isn't any problems.
A warm dry day usually works best for me when blasting in the cabinet.