PMB (plastic media) or glassblasting, whould it harm the housings to hit the houseing with any of this stuff? IE wil it not seal correctly

i use the glassblaster at work all ther time for aircraft brakes , so im guessing it wont **** up the housings, or would masking off what the rotar is exposed to be wise? or should i not do any of it?

 

I've used duct tape on the apex seal surface and left the water jacket/o-ring surfaces exposed. When you shoot just don't aim directly at the o-ring surface. When I clean the outside I just shoot so that face is away from the gun(around the corner from the edge). It probably wouldn't hurt with glass beads but I like to be safe.

 

just make sure none ever comes in contact with the inner surface of the housings.