6 Ways on How to Clean a Cast Iron Sink Basin or Bathtub and What Products Never to Use

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Cast iron tubs and sinks are popular choices for many homeowners because of their durability, lasting decades if taken care of. This material is usually coated with ceramic or porcelain which is then heated at extremely high temperatures, resulting in a smooth glossy finish.

However, in order to keep them looking new, they need to be cleaned regularly.

In this blog post, we will show you six easy ways how to clean a cast iron sink basin or bathtub. We will also tell you what products NOT to use so that you can prevent damaging the surface.

6 Easy Ways To Clean A Cast Iron Sink Basin And Bathtub

KOHLER K-6488-0 Whitehaven Self-Trimming Front Single Basin Sink with Short Apron, 36 Inch, White

These sinks and bathtubs look beautiful when they are shiny and clean. However, they can be quite an eyesore if they have scratches and start to accumulate dirt.

We will look at using natural products and chemical-based cleaners as different options, finding the perfect way on how to clean your cast iron sink or bathtub and bring out that shine.

How To Clean A Cast Iron Sink Basin And Bathtub With Baking Soda

Baking soda is readily available and can be used to clean the house without having any adverse effects, and the cast iron sink or bathtub is no exception.

  • Make a paste using baking soda and water
  • Apply the paste to the stained sink or bathtub
  • Leave to sit for about 15 minutes
  • Using a non-abrasive sponge, scrub the surface
  • Rinse the baking soda with water thoroughly

How To Clean A Cast Iron Sink Basin And Bathtub With Baking Soda And Vinegar/Lemon

A mixture of baking soda and vinegar is an excellent concoction because the vinegar is acidic and helps break down build-up and kills germs. Lemons are also acidic in nature and can be used with baking soda and using these together will eliminate those stubborn stains for good.

  • Make a paste with vinegar and baking soda
  • Apply the paste to the sink or bathtub and leave for about 20-25 minutes
  • Using a brillo pad lightly scrub the stained areas
  • Rinse with water
  • Cut a lemon into 8 wedges and sprinkle some baking soda into the sink or bathtub
  • Use the lemon wedges one at a time to scrub any leftover stains, you can use force here as the lemons will not scratch the surface
  • Rinse with water

How To Clean A Cast Iron Sink Basin And Bathtub With Bottle Cork

A cork is not only good for keeping your wine fresh. It is, in fact, a very good way to clean those marks and stains in the sink. It is the same as using an eraser on paper, and unlike other methods, you can use force here as the cork will not scratch the surface.

This is perfect if you have spotted a couple of marks in your sink or bathtub and want to deal with it without the fuss of cleaning the entire bathtub or sink. Simply take the cork and proceed to rub out the mark or stain.

How To Clean A Cast Iron Sink Basin And Bathtub With A Cast Iron Cleaner

There are a number of cleaners out there on the market that claim to be able to remove stains and return your sink or bathtub back to the glossy appearance that it once was.

We have listed a few below, but most of these have harmful chemicals, so make sure to wear gloves, goggles, and a facemask. Alternatively, you can use one of the non-toxic methods and avoid the hassle altogether.

Kohler K-23725-NA Cast Iron Cleaner

Kohler Cast Iron Cleaner

CloroxPro Clorox Commercial Solutions Green Works All Purpose Cleaner Refill, 64 Ounces (00457), Greater than 40 ounces, Gray

Green Works All Purpose Cleaner

Fantastik Advanced Kitchen and Grease Cleaner 32 fl oz

Fantastik Antibacterial Heavy Duty

Pour a small amount into your sink or bathtub of any one of these solutions and polish to remove the stains. Please make sure to read the instructions carefully before using them.

How To Clean A Cast Iron Sink Basin And Bathtub With Dishwashing Liquid

Sounds simple, we know, but here is the thing, if you clean your bathtub or sink after a couple of uses, you will not only keep it clean but make it impossible for bacteria to settle or minerals to deposit, prolonging the life of your sink or bathtub.

  • Just use a brillo pad and some dish soap and scrub the sink or bathtub until you have covered all the surface area, including all the small corners and crevasis
  • Rinse the bathtub or sink thoroughly, making sure to wash away all the soap
  • Dry with a microfiber cloth to eliminate the chance of any watermarks

How To Clean A Cast Iron Sink Basin And Bathtub With A Steamer

These devices have come a long way since the early versions. They are portable and easy to carry with lots of different attachments allowing you to get into the hard-to-reach areas. They are excellent at cleaning and quite inexpensive, so you can either buy one or rent one from your local hardware store.

Simply plug it in and add water and point and shoot. The steam that is emitted is extremely hot so caution is required, don’t forget to read all the instructions before using.

What Cleaning Products NOT To Use

There are so many ways to clean your bathtub or sink which will remove stains and not harm the enamel coating. However, there are some products that unfortunately get recommended on the internet that will clean your sink or bathtub but will damage the enamel with prolonged use.

We cannot list all the items as it would be too many, so we have listed a few of the popular products below.

  • Wire wool or wire brushes – they will scratch the surface and leave marks.
  • Magic eraser – when mixed with water, it becomes abrasive and will strip enamel.
  • Bleach – There are a lot of people that recommend bleach; however, bleach can discolor the sink and erode the enamel over time.
  • Comet cleaning powder – This powder is too abrasive for porcelain or ceramic and will damage the surface.
  • Abrasive cleaners – avoid any abrasive cleaners and make sure to read the instructions before using them on your sink or bathtub.

How To Maintain A Cast Iron Sink Or Bathtub

KOHLER K-2905-4-0 Farmington Self-Rimming Bathroom Sink, White

You have either just got a brand new sink/bathtub or you have just done a deep clean and you want to make sure it stays clean, at least for a while.

Bathroom Sink Maintenance

Kohler K-20212-W-0 Iron Plains 30" Cast Iron Drop-In, Undermount or Vessel Bathroom Sink with Overflow

Although you generally don’t put anything heavy in bathroom sinks, you still need to be careful with nail polish or heavy objects like hair dryers so they don’t damage the sink’s surface.

Small chips and scratches can be repaired, but we want to really avoid that. The most important aspect is to keep it clean by washing it once a week, especially if you have a lot of mineral content in your water.

Mineral deposits are corrosive and will harm the high-gloss finish of the sink’s surface. Therefore cleaning it using one of these methods should be a top priority.

Kitchen Sink Maintenance

30 Inch Undermount Kitchen Sink Black -Bokaiya 30x19 Black Stainless Steel Undermount Workstation Sink 16 Gauge Deep Single Bowl

Kitchen sinks tend to get dirtier a lot faster. You can avoid this by firstly not leaving dishes lying in the sink. If you are throwing leftover wine, tea, coffee, or any liquid or food that will leave a mark, rinse it out first.

It’s all too easy to drop a pot or glass while washing and have it slip out of your grasp, causing it to scratch or even chip the sink. By putting a cloth or silicone mat inside your sink, you can prevent scratches and chips while also protecting your dishes from breaking.

Avoid any abrasive cleaners or harsh cleaning materials like wire wools or brushes.

Keep your sink clean by washing it with detergent soap weekly and steam cleaning it once a month, eliminating any build-up of grim and killing germs.

FAQ’s Frequently Asked Questions

How do I get black marks off my cast iron sink?

Black marks could be the result of mold or grim and dirt stuck in the small scratches. The best way is to clean the black marks with a steamer and then use Kohler Cast Iron Cleaner to remove the scratches. Simply polish them out.

How do I get rid of white water marks from my sink?

White water marks are due to the high mineral content in your water supply. Use baking soda with vinegar to remove the marks. Make sure to always dry your sink after use, with a rag to avoid getting watermarks.

Is Bar Keepers Friend good for cast iron sinks?

Cleaning your cast iron sink once or twice with Bar Keepers Friend will not harm the surface however prolonged use of this cleaner will deteriorate the integrity of the enameled surface of the sink or the tub.

How do you restore the shine to a cast iron sink?

Most of the methods that we have covered above in this article will restore that shine back to your sink or bathtub. It is important to note that cleaning your bathtub or sink regularly will keep them looking shiny and new.

Do cast iron sinks scratch easily?

Cast iron sinks and bathtubs are generally coated with ceramic or porcelain and are very robust and can last a lifetime; however, misusing them by dropping heavy objects such as dishes, pots, pans or hair dryers will inevitably damage the sink causing chips and cracks. It is also very important to regularly clean the sinks and bathtubs.

How often should I clean my sink/bathtub?

It may surprise you to know that kitchen sinks have more germs than bathrooms due to food and alcohol. A kitchen sink should be washed down after every use and then dried with a cloth to prevent water marks from forming. You will need to use a steamer or a deep clean once a month to avoid bacteria build-up.

Sinks and tubs in the bathroom should be washed once a week but if you have hard water then twice a week would be ideal. A monthly deep clean is recommended in the bathroom to eliminate any bacteria that may be getting too homely.

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