Because of the delicate nature of the finish, abrasive cleaners can damage it. You must choose a cleaner wisely to ensure you do not scratch the coating of the tub. The best cleaner for cast iron tub surfaces is a mild dishwashing detergent.
Here's the magic formula to clean the nastiest, dirtiest, most iron-stained tub you have ever seen: White vinegar and Dawn dish soap (the blue kind is the best!).
The process involves sandblasting off the old finish, then baking on a new enamel coating at 1,475 degrees Farenheit for about four hours. “It's genuine porcelain enamel, the same glass coating used on bathtubs you buy in stores,” says owner Kara Kopplin.
It's important to not use anything too aggressive such as steel wool, sponges or other abrasive cleaning methods as these will strip your seasoning. For particularly difficult to clean messes, fill your pan halfway full with water and heat over the stove.
Upcycle the Tub
Cast iron tubs are used for more than just bath time. Clawfoot tubs can be repurposed into planters, couches, chairs and more with a little bit of creativity. Browse an idea board, like Pinterest, to choose a project that speaks to you. "You can create an outdoor flower bed or raised garden.
Mix 1 gallon of hot water with 2 tablespoons of non-abrasive cleaner or dish soap. Place the mixture into a spray bottle and hold it 6”–12” from the cast iron bath surface. If it's your first time cleaning the tub or using a new product, test a small, inconspicuous space first.
For cast-iron bathtub:
Bar Keepers Friend. Sponge. Magic Eraser (if there is a lot of soap scum buildup)
Heat vinegar in microwave until hot and pour into squirt bottle. Add the Dawn soap. Put the lid on and gently shake to incorporate. You now have a powerful cleaning product that will melt soap scum and tub and shower buildup, clean sinks, appliances and just about anything.
Soft Scrub is a gentle yet highly effective cleanser, making an excellent choice for cleaning a cast iron sink or tub.
Like magic, the Magic Eraser will start powering through tough grime in just a few swipes. Before you know it, your clean bathtub with shine like the top of Mr. Clean's head! And remember, you can also use Magic Eraser to clean other surfaces too.
It is also unwise to use acidic products on the enamel surface of a Cast Iron Bath. Using products ranging from vinegar to specialised bathroom cleaning products - which some people would use for an acrylic bath - wear away the enamel.
With proper care, your cast iron bathtub will last for decades, often 70 years or more. They are notorious for requiring less maintenance than an acrylic bathtub, which makes cast iron the perfect choice for a bustling bathroom.
For example, clawfoot and cast iron tubs are great sources of scrap metal and companies will potentially pay you more for your bathtub depending on the materials you have on hand.
Combining baking soda and water can help restore a bathtub to its shiny white gloss be removing dirt and debris; white vinegar can help kill bacteria and mould. These solutions are effective home remedies for common bathtub ailments, and they are much more affordable compared to most commercial cleaners.
Refinishing a bathtub is more cost-effective than replacing it. The average cost to refinish a bathtub is $490, compared to $5,700 to replace it. Refinishing can fix minor cracks, scratches, and discoloration. If your bathtub has major cracks or leaks, it's better to replace it.
Gently scrub the pan using mild dish soap, hot water, and a non-abrasive sponge (such as a Dobie sponge or the soft side of a Scotch-Brite sponge) or a scrub brush. Rinse it clean and then dry it completely with a dish towel.
Bar Keeper's Friend or baking soda will take care of any stubborn spots, and when you're done cleaning: just dry off and put it away. No seasoning required.
They are most likely carbon deposits. This happens due to overheating of fats and oils.