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Nerdy Science in the Kitchen

How to Clean a Cast Iron Sink

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Cast iron sinks have always been a popular choice because they are durable, easy to maintain, and most of all — pleasing to the eyes!

Kitchen interior with large rustic white porcelain sink and granite stone countertop under sunny window
Make your cast iron sink squeaky clean with our tips and tricks.

Cast iron sinks can come in either vintage or modern colors and styles, so you can easily choose which ones work best with your house design.

These types of sinks are made up of two layers: a heavy and durable foundation layer, and the thick enamel topmost layer. Both layers create an impermeable surface with a beautiful finish.

It nearly impossible to damage a cast iron sink; however, it is prone to rust, scratches, and stains if not maintained properly.

More often than not, life keeps us so busy that we leave our coffee grounds, tea bags, or dirty pans in the sink before getting busy washing and cleaning.

The longer we leave items like this in the sink, however, the more stains or even unintentional scratches form on your beautiful cast iron sink!

These are common issues, but worry no more: we are here to share tips and tricks about how to clean a cast iron sink and make it look like it’s brand new.

The Danger of Using Abrasives on Your Cast Iron Sink

When you are ready to clean your cast iron sink, first think about which are the right tools to use to avoid damage.

One important rule to remember is that you should not clean your cast iron sink with abrasive chemicals or materials.

Scouring pads or steel wool leaves a residue of small iron particles that can cause the cast iron sink to rust and corrode. Abrasive cleaners with chlorides and acid attack the sink’s protective layer, removing its ability to remain stainless.

Using abrasive tools like these–including wire brushes–will cause the enamel finish to tarnish or even wear off completely.

Instead, you want to use a mild soap (like dish soap) or any all-purpose, non-abrasive liquid cleanser that doesn’t include chemicals (such as chlorides or acid). Find the mildest cleaning tools and use them effectively.

How to Clean a Cast Iron Sink Using Baking Soda Paste

  1. Measure 1/2 cup of baking soda and 1/4 cup of vinegar.
  2. Pour both the baking soda and vinegar into a container and use a spoon to mix the solution. This process should result in the formation of a paste. In case the solution is too thick, you should add a bit more vinegar at a time until the paste is the right consistency.
  3. Once you have a baking soda and vinegar paste, rub it into your cast iron sink using a non-abrasive sponge. Rub in a circular motion until all dirt and scum are removed.
  4. Once the sink is clean, rinse it with tap water. You may also use a cotton cloth to remove the remaining visible paste.
  5. Repeat the above steps until your cast iron sink is shiny, spotless, and clean.

Arm & Hammer Pure Baking Soda, 12 oz

Arm & Hammer Pure Baking Soda Shaker - 12 Oz

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Arm & Hammer Pure Baking Soda is known to be America’s #1 Trusted Baking Soda brand.

It is great for scratchless cleaning, so you can scrub away the dirt, grease, and stains of your cast iron sinks without marring its beautiful protective finish.

It also works well with stainless steel, so it is indeed safe to use for cleaning. We recommend this because aside from its proven benefits, this specific product comes in a round plastic 12 ounce bottle, I especially like the snap top lid which helps when my hands aren’t cooperating.

Lucy's Family Owned - Natural Distilled White Vinegar, 1 Gallon (128 oz) - 5% Acidity

Lucy’s Family Owned – Natural Distilled White Vinegar, 1 Gallon (128 oz) – 5% Acidity

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Whatever your needs are, whether it could be for cooking or cleaning, Lucy’s Distilled White Vinegar is the best choice.

We recommend this vinegar as it also serves as a perfectly natural and chemical-free cleaning agent that can successfully remove your cast iron sink heavy-duty stains.

One more amazing fact about this product that proves its natural component is —it is made from corn!

Scotch-Brite Non-Scratch Scrub Sponges, 9 Scrub Sponges

Scotch-Brite Non-Scratch Scrub Sponges, 9 Scrub Sponges, Lasts 50% Longer than the Leading National Value Brand

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We recommend Scotch Brite as the best sponge for cleaning your cast iron sink because it’s totally non-scratch.

It is safe on countertops and non-abrasive, so it is the perfect partner for your desired deep cleaning.

Plus, if you are eco-friendly, you’ll love that its scrubbing fingers are 100% recycled.

Even better, it is cost-effective, since this pack comes with 9 sponges, which will keep you in stock for months.

How to Clean a Cast Iron Sink Using Bleach

It is essential to remember that it is not only enough to deep clean your cast iron sinks occasionally: it also needs to be cleaned regularly to maintain its sparkle and shine.

  1. Choose the non-abrasive bleach product of your choice, a spray bottle, and paper towels.
  2. Pour the bleach into a spray bottle.
  3. Cover your cast iron sink with layers of paper towels.
  4. Spray the bleach over the towels until they are soaked thoroughly. Leave for at least 30 minutes to an hour.
  5. Once done, throw away the bleached paper towels. Rinse your sink thoroughly to remove all the bleach. Repeat as needed.

Repugo Empty Plastic Squirt Spray Bottles, 17 ounces

Empty Plastic Spray Bottles(3 pack)–17oz Spray Bottle, Squirt Bottle, Plastic Spray Bottles for Cleaning Solutions, Hair, Essential Oil, Plants, Refillable Sprayer with Mist and Stream Mode

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This 3-pack of empty spray bottles is designed with a high-quality spray nozzle and a firm grip that won’t leak or get blocked.

Cleaning your cast iron sink is easier if you fill one of these with bleach and spray away! Use the extra bottles for homemade glass cleaner or other cleaning solutions.

Clorox HE Performance Bleach, 121 Oz. (Pack of 1)

Clorox Disinfecting Bleach, Regular - 121 Fl oz Bottle

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We recommend the #1 bleach of choice in America —Clorox Regular Liquid Bleach.

Clorox’s versatility is its number one strength, as it can be both used for cleaning and disinfecting.

It disinfects 99.9% of germs such as norovirus, E. Colli, or Salmonella.

It removes tough stains, and it safe to use on your sink.

Scott Shop Towels – 2 pack (2 rolls)

Scott Shop Towels Pack of 2.

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We highly recommend Scott’s shop towels for their ultra-strong durability–even when wet.

Although Scott’s shop towels are usually used in automotive maintenance, they are also perfect for deep cleaning cast iron sinks since they’re so thick and durable.

These towels come in a convenient pack of two, so you don’t need to run towards the nearest store to buy more once the first roll runs out.

How to Clean a Cast Iron Sink Using Commercial Products

  1. Prepare your preferred commercial cleaning product and non-abrasive or non-scratch cleaning pads.
  2. Squeeze the commercial product directly onto the surface of the sink or onto your soft sponges. Do not use anything abrasive like steel wool or wire brushes on your cast iron sink.
  3. Rubbing the stains in your sink thoroughly until they are removed.
  4. Rinse the cast iron sink well with running water.
  5. Repeat the process if you still have remnants of any stains.
  6. Use a soft cloth to dry your sink after each procedure.
Kohler K-23725-NA Cast Iron Cleaner

Kohler K-23725-NA Cast Iron Cleaner

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Our top choice when it comes to a non-abrasive cast iron sink cleanser is Kohler.

We highly recommend this product, as it works beautifully on enameled cast iron surfaces.

It has a premium formula that helps restore the sink’s shine. Also, it is widely known for the effective removal of marks, rust, stains, and other blemishes.

Rofesi Durable Scrub Scouring Sponge, Non-Scratch Microfiber Reusable Sponges, Heavy Duty Scrubber for Kitchen Cleaning Dishes and Pots (10 Pack, Multiple Colour)

Rofesi Durable Scrub Scouring Sponge, Non-Scratch Microfiber Reusable Sponges, Heavy Duty Scrubber for Kitchen Cleaning Dishes and Pots (10 Pack, Multiple Colors)

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For the softest and safest sponges, we recommend the Rofesi Durable Scrub Scouring Sponges.

Each one is made of high-quality materials that will leave no marks, scratches, or stains in your cast iron sink.

The sponge is dual-sided, composed of one softer microfiber side and a tougher scrubbing side.

It is indeed the best choice for cleaning a cast iron sink because you can guarantee a clean and scratch-free finish.

How to Protect Your Cast Iron Sink from Future Scratches and Stains

There are three ways to prevent stains and scratches from your cast iron sink.

First, wash your dishes, pots, or pans immediately after using. The more time they sit in your sink, the more prone it is to scratches and stains.

Second, do not leave your soft drinks, coffee, or tea bags in your sink, as these liquids and their remnants will definitely leave very tough stains in your cast iron sink.

Lastly, do not leave any mild steel or cast iron cookware in any part of your sink for an extended time. You should know that when iron and stainless steel’s moisture are present, unfortunately staining is the result.

Smart Design Sink Protector - Large - Steel Wire Frame - Rust Resistant Finish - Protects Sinks from Damages & Scratches - Kitchen (18.13 x 12.5 Inch) [White]

Smart Design Sink Protector – Large – Steel Wire Frame – Rust Resistant Finish – Protects Sinks from Damages & Scratches – Kitchen (18.13 x 12.5 Inch) [White]

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This steel-made, rust-resistant large sink protector has a smart design quality.

It is perfect for protecting your cast iron sinks from scratches, as you can place your dishes, pans, and pots to dry there after washing them without them touching the enameled surface.

This way, you can avoid leaving them anywhere in your sink, and it has the benefit of helping you become a bit more organized.

OXO Good Grips Silicone Sink Mat - Large

OXO Good Grips Silicone Sink Mat – Large

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The OXO Good Grips Silicone Sink Mat is made of PVC-free soft silicone that protects the sink from scratches and chipping.

It is a small-sized mat that can be great for double sinks!

Instead of placing your pots, pans, glasses, and dishes directly on your sink’s scratchable and stainable finish, you can place them here.

This mat is made of heat-safe silicone, so you can safely place your hot pots and pins directly from the stove on it without the danger of damaging either.

Additional Cleaning Tips

Aside from the cleaning tips shared already, we want to add five more easy tips to ensure that you maximize your cast iron sink care and maintenance routines.

  1. The best thing you can do every single time to maintain your sink is to make it clean and dry. After each use, rinse and then dry your sink using paper towels. This way, you can keep it shiny, free of water spots, and also prevent calcium formation.
  2. If you clean or scrub a particular stain in your sink, follow the grain line’s direction. Doing so prevents your cast iron sink from scratching.
  3. Never leave any wet sponge or cleaning pad overnight in your sink. It leads to discoloration of the sink’s surface.
  4. Never use your sink as your cutting board. Any sharp kitchen tools can damage your sink’s surface.
  5. Never leave mayonnaise, pickles, mustard, grease, or any food residue to sit in your sink for a prolonged time. This sadly leads to the pitting of your sink’s surface.

Conclusion

Cast iron sinks offer durability and beauty. But it’s important to remember they also need excellent care and maintenance.

Using the right non-abrasive tools is key to keeping your sink gorgeous and germ-free!

Frequently Asked Questions:

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

Purchase a cast iron sink cleaner that contains wax. Wax helps restore the shine of an enameled cast iron, and it also protects against surface damage.

Another suggestion is that, once you clean and dry your cast iron sink, you should apply a few drops of olive oil onto a lint-free cloth to polish the sink and make it really sparkle.

How do you get the black marks off a white cast iron sink?

You can begin by placing baking soda over the surfaces with black marks. Spray the baking powder lightly with water to help it stick.

After that, spray the surface of the sink with a safe, non-abrasive cleaning product. Then, scrub using a soft cloth or sponge until the black marks are removed. Repeat these steps as necessary.

Additional Resources:

HowStuffWorks: How to Clean a Cast Iron Sink

Image Credit from Flickr: “The Massive Sink” (CC BY-SA 2.0) by qgil

Kitchen Professor author
About the Author: Bryce Heitman

Bryce is not a real professor, but he's real nerdy in the kitchen. He's been barbecuing, chopping, and generally blazing food for many decades. He thinks there's definitely a better spatula or utensil out there that hasn't been invented yet.

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