Install an abrasive grinding disk if one is not already attached to the grinder: Grinders vary by manufacturer, so consult your owner's manual for instructions on installing a disk.
Turn on the grinder and grasp it with one hand on the handle and the other hand on the body of the grinder.
Hold the grind wheel against the surface you want to clean and move the grinder slowly across it as the grinding wheel sands away the Thinset: Don't press the grinder or you might damage your surface. Turn off the grinder and set it aside after you have cleared the Thinset away.
Brush off any dust left by the Thinset.
Things You Will Need
- Abrasive grinding disk
- Wear protective goggles when removing Thinset.