How to Remove Hard Water Stains from a Porcelain Sink

If vinegar alone doesn't work, a baking soda paste adds gentle abrasion to help lift the crusty buildup.

1. In a small bowl, mix 1/2 cup baking soda with 2–3 tablespoons of water to form a thick paste.
2. Apply the paste to the stained areas with a soft cloth or your fingers.
3. Gently rub in a circular motion, focusing on the crusty spots. Avoid scrubbing too hard to prevent scratching.
4. Let the paste sit for 5–10 minutes.
5. Rinse thoroughly with water and wipe dry.

For extra tough stains, you can add a few drops of white vinegar to the paste to create a fizzing action that helps lift minerals.

What Not to Do

• Do not use abrasive scrubbers like steel wool or scouring pads—they can scratch the porcelain.
• Avoid harsh chemical cleaners that contain hydrofluoric acid or phosphoric acid, as they can damage the finish.
• Do not let vinegar sit for extended periods (more than 30 minutes) on the surface, as it can dull the glaze.
• Never mix vinegar with bleach or other cleaners—this can create toxic fumes.

Fresh vs. Dried Stains

Hard water stains are usually dried mineral deposits, but the approach differs slightly depending on how long they've been there.

Fresh Water Spots

If you catch the spots soon after water dries, a quick wipe with a damp cloth and a little vinegar solution is usually enough. The minerals haven't had time to bond tightly to the surface.