Repair pitting in a cultured marble sink by protecting the drain, filling deep pits, sanding, buffing and applying a gel coat. Cultured marble is a mixture of stone and resin, making it lighter and easier to work with than natural stone.
- Cover the drain
Protect the drain and faucets with masking tape to prevent damage while working to restore the cultured marble.
- Fill deep pits
If the sink has deep pits, fill them with epoxy filler. Fiberglass repair kits for boats have the filler along with a color additive. Select the color closest to the cultured marble to make the repair less visible. Use an index card to smooth the filler in place.
- Sand the area
Use 400- to 600-grit sandpaper to smooth the filler, and then use 800- to 1000-grit wet or dry sandpaper to sand the area smooth. Cultured marble is uniform throughout, so sanding does not affect the pattern but does remove the shiny surface.
- Buff to a shine
Use auto-finishing compound to buff the area by hand. Then use a power buffer to polish the repair.
- Apply a gel coat
Make sure the sink is dry. Apply a gel coat designed for cultured marble over the entire top surface of the sink per the manufacturer's directions to restore the shine.