Forney 60025 Mounted Grinding 4 Inch Review

I received this to unroll the rim of a soda bottle for a water rocket application to help insert the launch tube with o-ring into the bottle. . I fill the bottle completely with water (so the plastic doesn't melt) and turn the grinding cone so that the inside edge of the bottle neck is no longer sharp. The abrasive cone works well when wet and I expect it to last a long time.