Sandstone is a relatively soft material. Over time, sculptures made from sandstone are subject to deterioration and may require repairs. While major repairs can be difficult and should be left to professionals, minor repairs to a sandstone sculpture can often be done using simple tools and methods. Taking the time to repair minor issues in a sculpture made of sandstone not only helps preserve the statue, it can help slow the process of further deterioration.
Remove rough edges around the area to be restored. Use a small rasp (metal file) and work slowly, running the rasp over the area to be sanded with slight pressure. File only to level the surface around the area to be repaired.
Brush away any filings and inspect the repair area. Run your fingers over it to ensure the repair area is level. If further sanding is required, continue to file with a light pressure, working slowly.
Mix sandstone filler or mortar according to directions on the box. Ensure the colour of the filler matches the colour of the sculpture as closely as possible. Apply the filler to cracked surfaces and gouges by pressing to avoid feathering of the filler material.
Always do as few repairs as necessary to avoid damaging the original lines of the sculpture. Any repairs to a sandstone sculpture will typically require some filing and filling. If you are repairing cracks and can do so without filing, this is the best approach.