You are not the only person who has reported a problem with the
quality of 3M Radial Bristle discs.
It should not matter that they are stored in sunlight, high or low
humidity. My collection of radial bristle discs are from 2007 and
they work great. However, if the plastic to manufacture them has had
a change in their formula, then higher UV could alter the action for
high friction to polish and snap off.
I do know that as of 2007 they were manufactured in the US, but the
base rubber component might have been changed and could be
manufactured over seas. I don’t know this for sure, but I’m guessing.
3M, like so much of our industry might have moved its manufacture to
China to cut costs and cut quality.
Which ones are snapping? Is it the Green final polish or are they
all exhibiting this problem.
Radial Bristle discs are wonderful, especially with etched or highly
textured metal where traditional buffs and compounds remove too much