Marble can easily become dull and scratched over time. Abrasive cleaners and everyday use can dull the finish of a marble surface. The finish can be rejuvenated, returning it to the clean glossy finish that it had at installation. The care of cultured marble is less intense than solid marble. Cultured marble has a coating that protects the marble from stains and scratches, it is less expensive, more durable and easier to maintain than solid marble. Solid marble is more costly that cultured marble. Solid marble is more porous and requires more extensive care that cultured marble. Marble can be refinished with or without sanding.
Wet-sand the marble, removing surface scratches and stains. To wet sand, make sure the sandpaper sheet is waterproof. Dip the sandpaper into a shallow container of water, just long enough to get the sheet wet. Gently sand the marble surface in a small circular motion with just enough pressure to remove the scratches and stains.
Rinse and dry the marble surface.
Buff the marble using marble polish. Use a buffing wheel with a cotton pad or hand-buff the marble with a lint free cloth. Use light pressure without rubbing the same spot for too long. The buffing will warm the marble, allowing the marble polish to bond with the marble, creating a smooth shiny coat.
Sand the marble lightly with diamond abrasive pads in a circular motion, changing the grit to finer pads until the original shine reappears. Marble is glossy as a natural property of the stone; to achieve the natural glossy look, grinding is the only option.
Buff the marble with a cotton cloth or buffing pad; use polishing powder to bring the shine back. This is a good maintenance technique.
Reseal the marble using an oxalic acid or tin oxide product. Dissolve the oxalic acid or tin oxide in warm water; follow the instructions on the container for exact measurements. Rub the sealant in a circular motion with a felt piece. As the marble warms, the oxalic acid or tin oxide will fuse with the marble. Oxalic acid requires less rubbing to penetrate the marble.
Rinse the marble with clean water after it has set for about three minutes. Let it dry completely.
Use a marble finishing wax to seal the marble. Gently apply in a circular motion, let it dry and buff the surface with a buffer or by hand. This will help protect the marble from future damage.
As an alternative to sanding cultured marble, fill scratches to restore lustre. Fill any fine scratches with car wax, appliance wax or a silicone sealant.
For cultured marble, sanding is effective for surface scratches; deep scratches cannot be sanded without damaging the marble beyond repair. Sanding too deeply can damage the coating making it difficult to bring back the glossy shine of the marble. For solid marble, do not use waxes and urethane; these are quick fixes and are not recommended for solid marble. Coating the surface blocks the marble from breathing, and can damage the marble when stripped later. When using oxalic acid wear safety glasses and gloves; the acid will burn your skin if contact is made.