How to Plane a Stone Surface

Plane soft stones with sandpaper. Wrap 40-grit sandpaper around a square sanding block. Remove the areas that are not level first. Continue with higher grit sandpapers until the stone is level. Lay the straight edge on the stone to check whether it's level.

Use hand tools to plane hard and soft stone. For hard stones, use diamond or carbide-tipped chisels. Begin with ripping chisels to remove stone from high areas. Continue chiseling with straight-point chisels to plane the surface. Use sandpaper or an angle grinder to flatten the surface after the majority of unwanted stone material has been removed by the chisels.

Plane the stone with electric hand tools. Angle grinders remove material from stone quickly, but create a lot of dust. Spray both the stone surface and the machine’s discs to remove dust after a few passes. Use diamond- or carbide-tipped discs if planing hard stone. Tighten a cutting disc to the angle grinder and pass it over the surface of the stone to remove large, unwanted areas. Replace the cutting disc with a 40-grit sanding disc and sand the stone. Continue with higher grit sanding discs until the stone is level.

Plane the stone’s surface with a high-powered pneumatic hammer. Use the pneumatic hammer when planing large or uneven stones. Pneumatic hammers work with air compressors and usually require between 70 and 90 PSI to tap away material from the stone rapidly. They can be rented for smaller jobs. Connect the air hose to the pneumatic hammer and attach a ripping chisel specifically designed for pneumatic machines. Use the ripping chisel to remove large strips of uneven stone. When the stone is almost level, change to a straight chisel and continue to plane the stone. Finish the stone’s surface with an angle grinder. Start with a 40-grit sanding disc and work up to a 220-grit disc for a smooth surface.