What kind of blasting you need depends on the part and what finish you want
Being the owner of a small blast cleaning company in North Yorkshire, I have had the pleasure in helping restore hundreds of classic bikes and thousands of parts, though I often have no idea where they would be found on your bikes.
There does seem to be a general confusion of which blast media should be used on which part, and I hope that I can help point you in the right direction.
Frames should be Grit-Blasted
Most motorcycle frames are cleaned by using a fine grit. The grit that we use is nearly the texture of dust, so that it does not pit the surface. Steer clear of friends who can put it through their automatic wheelabrator machines at work!! These machines use steel shot and will make your cherished bike's frame look like a cheesegrater. Any frame that has been powder coated should be dipped in solvent to remove the coating or soften it enough to blast clean the residue from the frame.
Aluminium casings can be Bead Blasted, Vapour Blasted or Soda Blasted.
Bead blasting uses a fine glass bead and give a good finish. If you use this method, ensure that you seal of the various ports in the casings. Not just with masking tape, but by making good seals and bolting them in position. An extra hours work will save you a lot of soul searching.
Vapour blasting uses the identical glass beads, but uses water as a cushioning agent and gives an even better finish that bead alone. The comments above about masking are equally as important here.
Soda Blasting works rather differently in that it works by effervescence rather than impact and is totally water soluble. This means that engine casings just need to be hosed down afterwards and all the soda is rinsed away. The finish of soda blasting is on par with bead but not as good as vapour. Where soda works better that the others is on painted metal. it will remove the paint without harming any of the surrounding surfaces.
Powder coated alloy wheels should be dipped prior to blast cleaning as the coating is more resilient than the aluminium and this can lead to damaged rims if the powder coating is not removed first. Balancing weights and the valve rubber housing should be removed so that those areas are cleaned also.
My Name is John and I can be found at Able Blast Cleaning. www.ableblastclean.co.uk 01765 603149 or 07870 145167 e-mail jc@1800.cc If you require any further information, just get in touch by whatever means you like.