How To Clean an Old Porcelain Enamel Bathtub or Sink

Apartment Therapy Tutorials

Cast-iron bathtubs and sinks are a common fixture in older homes, and now we're seeing them pop up in many newer remodels because of their unique vintage charm. Unfortunately, years of use or neglect can make for one discolored and dingy tub or sink! Here are a few tips to keep the porcelain on your antique fixture looking next-to-new.

Cast-iron is traditionally covered with a porcelain enamel that's fused to the cast-iron in a furnace. While porcelain is a highly durable surface, it's susceptible to chips, cracking, and a dulling of the finish. If you use the wrong products, you will accelerate the degradation of the surface, so let's begin by talking about what not to use. Abrasive cleaners such as scouring powders, white vinegar (or other cleaners with a high acidic content), and steel wool should all be avoided, as they can damage the finish. For the best results, always start with the gentlest cleaner and work your way up to more powerful applications. Remember, proper care will simplify ongoing maintenance.

What You Need


  • Liquid dishwashing soap
  • Ammonia
  • Baking soda
  • Lemon oil
  • Table salt
  • Lemon


  • Bucket
  • Nylon or soft sponge
  • Rag


For gentle weekly cleaning, mix 1 gallon of hot water with 2 tablespoons of dishwashing soap containing a grease cutting agent. Use a soft rag or sponge to dip into the soap mixture and scrub the tub or sink. Rinse well.

For monthly or deep cleaning (when moving into a new home or cleaning up a newly purchased vintage tub or sink), pour warm water into a bucket and add 1/4 cup of baking soda and 1/4 cup of ammonia. While baking soda is slightly abrasive, it's mild and generally safe to use on porcelain. The ammonia is great for cutting grease and removing soap scum buildup.

  1. Soak a non-abrasive sponge in the baking soda/ammonia solution. Scrub the surface of your porcelain bathtub or sink, paying particular attention to stained areas.
  2. Dip the sponge in the solution, scrub and repeat until you're satisfied.
  3. Rinse well.
  4. After rinsing, wipe thoroughly with a clean rag or the baking soda will leave a white film behind.

For tough-to-remove rust stains (and as a last resort), cover the stain with table salt. Take half of a lemon and squeeze the juice over the salt. Scrub the salt/lemon mixture with a clean cloth or a nylon sponge. If the stain still doesn't come up, leave the paste-mixture on the stain for an hour or so. Squeeze more lemon juice on the stain and try scrubbing the stain again, then rinse and wipe clean.

To add shine and a protective coating, squeeze a small amount of lemon oil onto a clean rag and rub the lemon oil into the sides of the porcelain bathtub or sink, avoiding the bottom of the tub to prevent slipping. The lemon oil will help repel soap scum and other dirt to keep the sink/tub clean longer, and it smells good, too!

Additional Notes:

  • Bathtub rings can usually be blamed on oily bath products or a clogged drain. Keep the drain clog-free, and if you use a bath oil product, make sure to do a quick cleaning afterward.
  • It's always wise to test a small hidden section first to ensure that the cleaner will not cause any adverse effects to the surface of the porcelain.
  • If none of these suggestions work and your tub or sink still looks a bit lackluster, it might be worth the investment to have your fixture re-glazed by a professional. While there are DIY re-glazing kits on the market, the results are usually shoddy and do not last. Unlike fiberglass or acrylic, your cast-iron fixture can stand the test of time, so it's well worth the expense to hire a specialist for the job.

Edited from an original post published on January 20th, 2011 by Kimber Watson

Have a really great DIY project or tutorial that you want to share with others? Let us know! We love checking out what you're making these days, and learning from our readers. When you're ready, click here to submit your project and photos.

(Image credits: Ashley Poskin)