How to Polish and Seal Granite Countertops

Polishing granite gives it a shine.

Granite countertops can be beautiful, but granite is not naturally slick and shiny. The rock must be polished before it will show a glossy appearance. Because of the porous nature of granite, it absorbs liquids that are left sitting on the surface for any length of time, which can stain a countertop. Applying sealant helps prevent staining and keeps the granite looking new. It is wise to both polish and seal your granite countertops before using them.

Things You'll Need

• 50- to 3,000-grit diamond polishing pads
• Washcloths
• Granite sealant

Instructions

1. Sand the granite surface, beginning with a 50-grit diamond polishing pad. Start with the edges and work your way in. Continue to polish the entire surface with the polishing pad until the grit of the granite ceases to change. You will know when this occurs because you will meet less resistance while sanding.

2. Change to an 80-grit polishing pad and resand the granite countertop. Work your way up through all eight grits until you reach a 3,000-grit polishing pad. At this point the granite countertops will have a glossy surface.

3. Wipe down the newly polished countertops with a slightly damp washcloth. It is important that the cloth you use contain as little water as possible since the granite has not yet been sealed and residual water from cleaning can stain it.

4. Allow the countertops to dry for 24 hours. If you have a fan, direct the fan to blow onto the granite.

5. Apply granite sealant to a clean, dry washcloth and rub it lightly across the surface. Be sure to cover the entire surface.

6. Allow the sealer to dry completely. This normally takes from 15 to 30 minutes.

7. Apply a second coat of sealer in the same manner. Give the second coat a few minutes to absorb into the stone, then buff it off with a clean, dry cloth.

Tips & Warnings

• You may opt to purchase or rent a water polishing machine to make the polishing job go more quickly.

• Depending on the size of the granite surface to be polished, each polishing pad may run out before the job is finished. Have multiple pads of each grit available just in case.

• While polishing the granite, you may stop before reaching the 3,000-grit pad if you prefer a matte surface rather than a glossy one.

• Even if you are using a "permanent" granite sealant, expect to seal again in about 10 years.

• Do not skip grit levels when polishing the countertop as this may give your finished product a cloudy appearance.

References

• Ask the Builder: Granite Sealer

Resources

• Read this Article in Spanish