The old sill is chiseled out or cut out entirely. A new预制 (pre-cut) stone sill is mortared into place.
Mix your chosen compound according to the manufacturer’s instructions. Use a small pointing trowel or a putty knife to press the material firmly into the gap. Overfill the area slightly, as most materials shrink slightly as they cure. 4. Texturing and Shaping how to repair stone window sills
The material you use depends entirely on the type of stone and the size of the damage. The old sill is chiseled out or cut out entirely