How To Clean a Cast Iron Tub? Newbie Guide

Cast iron bathtubs are often the first choice of fashion enthusiasts for their classy and vintage look. We often neglect the cleaning part thinking that nothing can damage an iron tub. While it is true that cast iron bath tubs are highly durable – in reality, cast iron tubs need extra care to maintain their shiny appearance. This kind of tub is typically covered in a porcelain enamel coating which is prone to scratches, stains and dulling over time.

No reason to worry though, because cast iron tubs can be easily cleaned with just a few ingredients which are most likely to be available in our kitchen cabinet. I will be showing three effective methods for your convenience.

What Is A Cast Iron Tub Anyway? and How To Clean a Cast Iron Tub?

Before we begin with learning how to clean a cast iron tub without damaging it, it’s important to understand what exactly you would be dealing with. A cast iron tub uses very old technology, and that is why you see many of these tubs in vintage style. Theoretically, they can last forever when cared for properly.

The tub is actually made of porcelain and iron fused together. While that’s enough to make it very hard and durable, manufacturers of cast iron tubs add an enamel coating on the tub to keep it from chipping. This further increases it’s durability. One of the most desirable features of a cast iron tub is that it hold heat for longer. Cast iron takes a long time to heat up, but it naturally absorbs heat and holds on to it for a long time (that’s why cast iron pans are great for deep frying chicken, they hold the temperature well). This was very important in the past when hot water was not so easily accessible (there were no electric water heaters in Victorian times), so people could enjoy longer baths with no issues. Nowadays, if you feel that the water’s temperature is dropping too low, you can just top it off with a little hot water from the tap, which was not as simple in the past.

What Not To Use On Cast Iron Tub

Using the wrong product can degrade the tub surface leading towards semi-permanent damage. So before proceeding with the cleaning techniques, it is better to list down the “Don’ts” for cleaning cast iron tubs.

Abrasive Cleaners

Any kind of abrasive cleaner like scouring powder or steel wool should not be used on cast iron tubs. This kind of harsh products can damage the finishing of the tub. While this type of product may seem to make things easier at first, the tub will be more an more difficult to clean over time. Caring for your cast iron tub means trying to maintain it in the same condition it was when it was brand new (or when you first got it restored).

Over time the damaged enamel coating will start absorbing dirt, grimes and will leave with no option than expensive refinishing. So, it’s best to avoid causing scratches in the enamel from the start.

Corrosive Cleaners

Excessive use of corrosive cleaners like bleach can also harm the finishing. It might give an instant cleansing, but the enamel coating washes away little by little every time you use it. In the long run, the surface will be rough, discolored and ruin the look of your precious vintage tub. Don’t be fooled by oxygen bleach thinking that it is less harsh than chlorine bleach. All types of bleach are harmful to cast iron tubs.

Cleaning A Cast Iron Tub

It is a relief that cleaning a cast iron tub is not that big of a deal. There are plenty of techniques to wash it. The best part is none of the methods require any fancy chemicals or tools like the other materials.

Most of the required products can be found in your grocery store. These are non-chemical mild products which will not cause any damage neither to your tub nor your skin.

Method 1: Using White Vinegar

This is the most effective method used by most people. Want to know why? Keep on reading to find out.

What You’ll Need

  • White vinegar (to help dissolve the soap scum and any limescale)
  • Sponge (choose a soft kind to avoid scratching the enamel)
  • Baking soda (this will help provide mild abrasion and has a detergent effect when it reacts with vinegar)
  • Scrubbing Brush (not the very harsh and abrasive kind)
  • Microfiber cloth (choose a soft type)


The entire process is stated below in a step-by-step format. Follow it accordingly and you shall have a smooth cleaning session.

  • The first step is to saturate the tub with white vinegar. It’s better not to pour vinegar directly on the tub because it will be drained away and will not cover the surface.
    Saturate a sponge with white vinegar and then sponge the whole tub very carefully so that no area is missed. Keep it for 5 minutes for softening the stains.
  • Sprinkle baking soda on the tub covered with vinegar. It will create a foaming reaction which will demolish the minerals making it easier to wash away the stains. If the stain is stubborn, use a scrub brush to clean.
  • Rinse the entire tub with warm water and keep scrubbing with a sponge to ensure no dirt or stain is left over. Make sure that not only the bottom but the side of the tubs are also washed.
  • Wipe the wet tub with a sponge or microfiber. Let it dry. Thus the cleaning is completed.

Method 2: Using Liquid Soap

An unconventional but really effective method. Let’s know about the details below.

What You’ll Need

  • Liquid dish soap (to dissolve the soap scum and dirt that has accumulated on the tub’s surface)
  • Sponge (soft, to avoid abrasion)
  • Microfiber (soft, to avoid abrasion)


Here we have the entire procedure laid out for you. Follow the step-by-step guide to clean your tub well.

  • Fill the tub with warm water and mix a few drops of liquid dish wash. Choose the dish wash with a grease-cutting formula for the best result. Let the bubble form and keep it for 30 minutes.
  • After 30 minutes unplug the tub and drain the foamed water. Use a sponge to clean and scrub the tub. Then rinse and wash the entirety of the tub.
  • Wipe the tub with a microfiber cloth. Let it dry, and thus the cleaning process is complete. Drying prevents spotting, stain formation and it helps the tub hold the shine.

Method 3: Using Lemon And Salt

Using lemon and salt has proven to be one of the most effective methods in the past. Let’s know the details then.

What You’ll Need

  • Table salt (this will provide milk abrasion that is not going to scratch the surface of the enamel)
  • Lemon (to dissolve the dirt and soap scum, and leave lasting anti-microbial oil on the tub’s surface)
  • Sponge (as usual, choose a soft type, to avoid abrasions)


Follow this process step by step. It is a tried-and-tested procedure which will make the entire cleaning process very easy and simple.

  • Sprinkle salt on the tub aiming at the stains formed on it.
  • Squeeze half of a big lemon. Pour the lemon juice on the salt.
  • Scrub the salt and lemon mixture delicately with a sponge or clean cloth. Give extra effort to the stained areas.
  • If the blemishes remain, add more lemon and salt mixture to the stained area and let it rest for one hour.
  • After an hour, repeat the scrubbing process. By that time stains should be softened and easily removable.
  • Wash the tub with warm water. Wipe out the water and let it dry. Enjoy the freshness of lime cleansing from next use.

Chips In The Enamel  Coating

One of the more difficult problems to solve with cast iron tubs is when the enamel layer (which is actually there to protect the porcelain/cast iron underneath) chips away. These chips could lead to rust that would eventually weaken the structure of the cast iron with repeated exposure to water. However, don’t fret. If you’ve looked up how much it costs to re-enamel a tub, you’re probably thinking of giving up and getting rid of the old thing. But if you inspect your cast iron tub regularly and find the chip when it is still small, you can re-enamel the small area on your own, but the process is a little more complex than cleaning.

Painting A Chipped Cast Iron Tub

This is our brief guide to help you bring your chipped cast iron tub back to life. Keep in mind that this is a laborious process that will take a lot of time and energy. If you are not committed to doing the entire process yourself, you may prefer to hire a professional to do it for you. However, it is much cheaper to do it on your own – if you are inclined to do so.

  • Clean the tub thoroughly, according to the instructions we’ve provided above. You will also need to remove any hardware and tapware from the tub.
  • Scrub away loose paint chips and enamel flakes using a stiff wire brush. Clear everything away using a rag and dry the tub fully.
  • If your cast iron tub has been previously painted, you will need to strip away the old paint using a paint thinner or other appropriate chemicals.
  • Preferably, sandblast the entire tub’s surface to make it smooth and even. You can try using sandpaper instead but even with an electric sander, the results won’t be as good as sandblasting. This will make the next step easier.
  • Use a galvanized metal-etching primer, applying an even coat all over your cast iron tub. The primer will facilitate bonding of the final coat of paint to give a long lasting finish.
  • Apply the waterproof paint (make sure you are choosing the appropriate kind, it should not be water-based latex or acrylic paint). You should wait for each coat to dry before applying a next coat. Most experts recommend applying at least three coats of paint.

Note that this process would likely take around 3 days to complete. However, we think it is worth the hard work and the wait, because it will result in a long-lasting finish that won’t peel or flake easily. With a little hard work, you’ll have your cast iron tub as good as new.

Also, keep in mind that painting your cast iron tub is only suitable if you have light scratches or chips in the enamel. Some cast iron tubs require more serious makeovers, and for that you’ll probably want to hire a professional to re-glaze the tub. It’s a costly procedure and is not suitable for home workshops – re-enameling requires handling enamel that has been melted at high temperatures. Still, refurbishing a cast iron tub is a cheaper alternative to buying a new one.


Now that you know how to clean a cast iron tub, you may be interested in how to maintain it. This will make clean up easier for you and prolong the life of your tub.

  • After every use rinse the tub carefully and wipe it dry. It will prevent the formulation of soap scum or stains. This is especially important if you live in an area with hard water, because the moisture left in the tub will leave calcium deposits (limescale) which can be difficult to clean and encourage bacterial growth.
  • Do not use rough cleaning tools like steel wool while cleaning because it might leave scratches. It is safe to use a sponge, preferably on the soft side (as you would do with a Teflon pan).
  • Drop some lemon oil on a cotton pad and wipe your tub with that pad. Lemon oil helps to keep the surface clean and fresh. Also, lemon oil has been proven to have inhibitory effects that help find against microbial growth. This is why many cleaning products are lemon scented.
  • Clean your drain regularly so that it does not get clogged. Clogged pipes create more soap scum on the tub. Not only that, but repairing a clogged and possibly broken pipe would be costly and require a lot of manual labor, especially if you need to move the tub to access the pipes.
  • Whenever you try any new cleaning element it is better to start with a little portion, not the whole tub at a time, the reason is to check if the new cleaner is creating an adverse effect on the enamel coating of the tub. If you notice any changes or discoloration, immediately wash the area and of course do not use that cleaner again.

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Advantages of Using A Cast Iron Tub

  • Cast iron tub is considered to be the most durable among other materials available. Its enamel finishing allows it to be resistant to scratches, dents, and cracks.
  • The surface of the tub is easy to clean, and the shine remains for an extended period.
  • As it is thick and deep, it helps to keep your bathwater warm for a longer period, which is also a function of the cast iron used to make the tub.
  • You can choose either a Victorian-style freestanding tub or a wall-supporting tub according to your preference and budget.
  • Unless a cast iron tub is broken (which is very difficult to do), it can restored completely by taking it to a professional service.

Disadvantages Of Using A Cast Iron Tub

  • Cast iron tubs are extremely heavy. They usually weigh around 350-500 pounds (when empty), but can be heavier. It requires extra manpower and labor to transport and install a cast iron tub. Also, you must consider whether your floor is stable and strong enough to house a cast iron tub, you may need reinforcements.
  • Because of its durability and vintage look, the cast iron tub is usually very expensive when compared to other tubs available.
  • Cast iron tubs are massive by itself. When bathwater is added, it becomes heavier. So based on the construction of your bathroom, this tubs often require extra floor support for safety. Most contractors prefer to place cast iron tubs on a concrete floor, or on the ground floor. Otherwise, they must take extra precautions to avoid the tub falling through the floor after some time.
  • Once the enamel coating is scratched or cracked, it will rust the cast iron tub eventually costing a considerable amount of money for repair or replace, or a lot of work if you want to do it yourself.
  • Although the vintage style of the cast iron tub is a classic aesthetic that many people look for, there aren’t many options when it comes to shape of cast iron tubs. Acrylic tubs can be designed and shaped into practically any size an shape, but cast iron tubs are limited to two general designs.

Comparing Cast Iron Bathtubs And Acrylic Bathtubs

By now you may be wondering if the aesthetics of a cast iron hot tub are worth the trouble. Yes, it’s durable, but there are a lot of finnicky things when it comes to caring for the tub. Acrylic tub are the commonly found modern type of bathtub, and they are certainly cheaper than the cast iron equivalent. So how do the two compare? Here are a few things to keep in mind when shopping for bath tubs, which can help you decide between acrylic and cast iron.

Chipping, Cracking, And Scratches

While cast iron tubs are known for their durability, they are prone to scratches and chips in the enamel coating. Acrylic tubs are typically reinforced with fiberglass. This means that they are comparatively resistant to chipping, cracking, and scratches. However, it’s worth mentioning that if an acrylic tub is chipped or the finish is damaged, there is no way of repairing it for a long lasting result the same way that cast iron tubs are re-enameled.


As we’ve previously mentioned, cast iron tubs come in only a handful for shapes and designs. This is because they are poured into a mold. On the other hand, The material used in acrylic bath tubs is highly flexible, giving way to more variety in their design.

Heat Retention

Even with the advent of insulated acrylic tubs, cast iron tubs still offer superior heat retention. This is especially desirable in regions where the climate is cold for the majority of the year. After all, who wouldn’t want to soak in a tub of hot water for prolonged periods of time? The relaxation is incomparable.

Budget And Impact On the Environment

As you’d expect, cast iron tubs are expensive to purchase and also expensive to install. Acrylic tubs are the more affordable option, but it’s worth mentioning that they are not environmentally friendly because the materials can’t be recycled. While most damaged cast iron tubs can be refurbished, even those which cannot be salvaged can be melted down and recycled. Acrylic tubs are so affordable that most people would rather replace the entire tub than go through the trouble of repairing it. This then leads to the accumulation of waste, and acrylic tubs are seldom recycled. In our opinion, if you care for the environment, then you should definitely consider getting a cast iron tub.


The demand for cast iron tub has never decreased, mainly for its vintage and classy appeal. We can only hope that our guide helped you learn how to clean cast iron tubs easily. Proper maintenance is vital for ensuring the durability of such tubs. Years of use or negligence can turn the tub discolored and bland, or lead to chipping of the enamel coating of the cast iron tub.

If it is cleaned regularly and used with care, stubborn stain or soap scum cannot form on the surface which keeps your precious antique-looking tub stay good as new. As we’ve previously mentioned, these tubs can last several lifetimes when cared for properly, which makes the initial investment worthwhile for many people. After all, wouldn’t you rather have something that can stay in style forever?

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