I use this tool with 80 grit sandpaper and an extension. I was able to sand down a lot of roughness and together with another round tool and a finer grit I get a very smooth finish for my paint jobs like doors and interior panels. I even go back and re-sand and re-paint some of the rough spots. Sanding is all that is needed for a good finish. I wish I knew about this principle before I did all my doors and a bathroom. These grinders are better and easier to use than electric grinders.