How to Refinish a Porcelain Sink

Old porcelain sink

Porcelain sinks can last at least a hundred years although the finish will degrade with hard use and it might develop cracks and chips. But some sinks are so interesting in shape and style that they are well worth refinishing. This process often takes some hard work to turn out good results but for heirloom sinks it can be like saving an old friend.

Things You'll Need

• Dish soap and water
• Scrub brush (bristle type)
• Old toothbrush
• Paper towels
• Chlorine bleach
• Rubber gloves
• Eye protection
• Plastic sheeting
• Tape
• Towel
• Acetone
• Silicone digester
• Scraper or putty knife
• Utility knife
• Distilled water
• Drop cloth
• Paint suit
• Respirator
• Hydrofluoric acid etcher (or other chemical etcher recommended by manufacturer)
• Solvent degreaser (as recommended by manufacturer)
• Rags
• Rental sprayer (high velocity low pressure)
• Epoxy primer
• Polyurethane, acrylic urethane resin paint (or similar)
• Acrylic urethane clear coat
• Porcelain repair kit (optional)

Instructions

Refinishing A Porcelain Sink

1. Scrub the sink thoroughly with mild dish soap and water. Use a bristle brush or old toothbrush to get into crevices and corners. Any dirt left on the porcelain will look like a defect in the new finish. Rinse well.

2. Remove rust stains by plugging the drain and laying six to 10 paper towels in the bottom of the sink. Pour chlorine bleach directly onto the paper towels. Wear rubber gloves and eye protection, during this step. Leave paper towels in place for several hours. For rust stains further up the bowl create paper towel pads of the right shape to cover the stain, saturate the pads with bleach,cover them with plastic sheeting and tape to hold them in position and to hold the bleach inside the plastic. Tape the pads in place and leave them on for several hours (6 to 8 hours or overnight). Keep children and pets away from the area. Keep the door closed and ventilate the room well.

3. Rinse the sink thoroughly so that no chlorine remains. This is important because the bleach could have a chemical reaction with other chemicals in this process. Remove from work site and dispose of all chlorine-soaked pads and plastic. Wipe the sink dry when finished.

4. Clean sink with acetone to neutralize additional grime. Rinse with water and dry thoroughly.

5. Use the silicone digester and a scraper or putty knife if there is any evidence of putty or caulk. The digester will help to remove all traces of silicone or caulk. Use a utility knife for any large sections. Rinse the sink clean using distilled water. At this point it should be spotless and any repairs should be complete. When possible, remove the fixtures so that the new glaze will cover the entire surface.

6. Tape and mask off everything around the sink, such as walls. Pay particular care to mask off any faucets or drains that are being left in place. Tape sticks best when the surface is very dry. The paint sprayer will overspray, so spread drop cloths on the floor. Allow for good ventilation when possible.

7. Wear protective paint suit, eye protection, gloves and respirator. Use hydrofluoric acid (or other chemical etcher recommended by the manufacturer of your products) to etch the surface of the glazing that is still present on the sink. This is necessary in order for the primer to adhere to the surface of the sink.

8. Wipe down the sink with a solvent degreaser to remove all traces of the acids (this should come with the acid product but double check that the chemical is used to remove hydrofluoric acid). This should neutralize the acid. Use disposable rags or paper towels for this process and discard them immediately.

9. Spray primer on the sink. This will take two or three thin coats. How well the primer sticks to the sink will greatly influence the longevity of your new finished surface. The primer manufacturer will note how long each coat should dry before applying the next coat. This is generally 20 to 30 minutes, but it may be longer. Allow the final coat to dry for much longer. Overnight is optimum but at least 2 or 3 hours.

10. Spray up to 12 thin coats of acrylic urethane resin paint on the sink. The paint finish is built up slowly. Spray by moving the wand evenly from side to side releasing (stopping) the paint just beyond the sink. Check the paint container to see for how long to wait between coats. It is normal for the paint process to take 6 to 8 hours to complete. If the sprayer is held too close to the sink you might have to stop the refinishing process due to drips. Wait until the paint is very dry (2 to 3 hours) and then sand the spots and wipe the area clean before continuing.

11. Finish the sink by spraying several coats of high-gloss clear coat to bring up the shine. Allow for sufficient drying time between each coat.

Tips & Warnings

• This project is best done over a long weekend when the house is empty and the refinisher can work undisturbed. Protect the sink from any kind of debris during the paint and clear coat applications as dirt can become lodged in the new finish.

• The chemicals used in this process should not be inhaled by children, pets or any person not wearing a good respirator mask. Check with your local disposal company for the correct way to dispose of volatile materials.

References

• Refinishing Online
• Integrity Coatings

Resources

• Read this Article in Spanish