A typical example is engine cases. Early examples were sand cast using fine particle sand, giving them a smooth matte finish. To reproduce this finish during a restoration requires that the cases be fully cleaned and degreased, followed by careful bead blasting.
However, to give the same appearance as the originals, a fine glass bead should be used in place of grit or beads in the blaster.
Another application for this finish is on spokes, or more precisely where stainless steel spokes have replaced the original plated items. Before fitting the spokes to a rim, they can be blasted with fine glass beads to give them the original appearance (remember to cover the threads before blasting).
Note:
- A word of caution. Any blasting using high pressure compressed air can damage components. It is particularly important not to concentrate the spray in any one area for longer than a few seconds as localized heat distortion can take place.
Further reading: Classic-Motorcycle-Parts-Grit-Blasting