A big risk
Guys, I'm with Paradism on this one. I have been personally associated (but not directly involved) with an investigation into the failure of a police motorcycle rider's helmet when it impacted a concrete gutter and resulted in the subsequent demise of said officer. I have seen three-point bend tests where the virgin helmet material was stressed without failure and then a few drops of a common cleaning solvent were applied and failure was almost instantaneous. Evidently the officer was cleaning his helmet with that solvent on a regular basis.
I wonder how many readers ride motorcycles and clean their helmets with solvent?
I would want to see strong test evidence to show a reasonable outcome before I re-painted something on which my life could depend.
Regards
Blakmax