Flap Wheel Grit Size
When selecting a grit size for a flap wheel, start with the finest grit possible to do the job. Keeping in mind whatever you put in, you have to take out. If a series of polishing operations is required it is suggested to skip no more than 2 grit sizes between operations.
For example, first operation - 80 grit, second operation - 150 grit. If more than 2 grit sizes are skipped, there may be difficulty in removing grit lines from the first operation.
In matching a flap wheel to an abrasive belt, go 2 to 3 grits coarser on the flap wheel (i.e. to approx. A 120 grit belt, start with a 80 grit flap wheel).