Porcelain can turn dull over time and with frequent use. Soap scum can leave a white film, and food, toothpaste and rust can build up over time. You can clean a black sink with several products you already have at home. HowStuffWorks recommends always using cloth towels, sponges and nylon-covered pads for porcelain. Using abrasive or harsh cleaning pads can cause scratching and damage the finish.
Use Kitchen Products
To get dirt, food stains and grease out, liquid dishwashing detergent is great according to HowStuffWorks. Scrub stains away with a sponge and rinse thoroughly. The stains will disappear and the shine will be restored.
For dark stains on a porcelain sink, like coffee, tea, wine or juice, try using baking soda. Using baking soda and a damp washcloth, scrub until the stain is gone and rinse thoroughly with water. Full-strength white vinegar is great for porcelain sinks, according to Reader's Digest. Scrub thoroughly, then rinse clean with cold water. Repeat if needed. This all natural cleaner is great for tougher stains.
Use Borax for Dark Stains
Borax, also referred to as sodium tetraborate, works great for difficult stains, especially rust. Reader's Digest suggests making a paste that consists of 1 cup of borax and 1/4 cup of lemon juice. Place the paste on a sponge or cloth towel and scrub the stain thoroughly. Rinse the sink out with running warm water. Wear gloves when cleaning with Borax because it can cause skin irritation. You also don't want to inhale Borax or get it in your eyes.
Clean it With Ammonia
Soap scum can leave a white film on your black porcelain enamel sink. Grease and other food buildup can be difficult to remove. For more stubborn stains, Reader's Digest suggests mixing 1 tablespoon of ammonia in 1 gallon of hot water. Rinse thoroughly when done to remove the ammonia completely. Wear gloves when cleaning with ammonia. It can cause irritation if it comes in contact with your skin. Also ventilate the room when cleaning with ammonia.
Try Hydrogen Peroxide
For white or colored porcelain sinks, try using liquid oxygen bleach, such as hydrogen peroxide. It is less caustic than bleach according to Bob Vila. Pour the hydrogen peroxide into a spray bottle. Wear gloves when cleaning with hydrogen peroxide. Line the sink with paper towels and spray the hydrogen peroxide on them until they are saturated. Allow the paper towels to sit and soak for 30 minted to an hour. Rinse thoroughly with clean water.
Buy a Mild Abrasive Cleanser
If you want to use a commercial cleanser, Bob Vila suggests using a mild abrasive liquid. Bar Keepers Friend is a great product. First wet the surface of the sink. Next, use a small amount of cleaner and let it sit for approximately 1 minute. Leaving it on for longer could cause discoloration.
Gently scour the surface with a nonabrasive sponge. Bar Keepers Friend contains oxalic acid, which is great for lifting stains. However, only use a little bit since too much can cause scratches or even discoloration since porcelain is so delicate. Rinse out the sink thoroughly after.
Use Naval Jelly for Rust
For difficult to remove rust stains, Bob Vila suggests using naval jelly. Naval jelly is a rust dissolver that can be purchased at most hardware stores. Spread a thin coat to the stained area. Monitor the stain carefully and rinse off the naval jelly as soon as you see a change in the stain color.
Naval jelly is most often used to remove rust from metal, so be careful when using it on porcelain. Rinse it completely off as soon as the stain is removed to prevent damage. Wear gloves while using naval jelly to avoid contact with your skin.
You can use a porcelain sink sealer to repair more severe damage or composite sink sealer for granite and quartz sinks. Frequent cleanings can help prevent soap scum build up and keep your sink from looking dull. Always clean the stain as soon as possible so it does not have time to set in. Too much abrasion can damage porcelain sinks, especially older ones or antiques. Your black porcelain sink will be sparkling and shining like new again after using these cleaning methods.