How to Repair Microwave Rust

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Updated February 12, 2023
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Difficulty Medium
Steps 7
Time Required 120 minutes
Things to Know

Even if you have a top-tier microwave, all appliances break down over time. One issue you may see is that the accumulation of food debris and moisture in the microwave oven cavity will cause rust. It should be clear that rust is not microwave-safe and might cause dangerous arcing inside your appliance. Any kind of malfunctioning electrical component will make your device unsafe and is a genuine fire hazard. So, to keep your home safe and maintain food safety, you need to know how to repair microwave rust.


  • Rust in the microwave cavity is a dangerous issue that you need to treat immediately.
  • Clean the rust spots in the microwave and sand away any debris.
  • Use microwave-safe paint to apply multiple thin coats to the rusted area. Make sure to let the paint dry before cooking in your microwave.

Please keep in mind that, no matter how you look at it, a rusty microwave oven is a safety hazard, and it’s possible that you may have a device beyond repair. If there is a high amount of damage to your unit, a coat of paint won’t help. In addition, if your rusted microwave has external surface rust and a cavity with multiple damp rust spots, it may be too late. This is a far more serious situation than a defective microwave oven that starts when the door is open.

For more articles on microwave repair, check out how to fix a microwave door switch and how to repair a magnetron in a microwave.

So, assuming the damage isn’t too bad, grab some microwave-safe paint, and we can fix your rusty microwave.

Insider Tip

If your microwave is heavily damaged by rust, it’s best to simply buy a new unit.

How to Fix Microwave Rust Damage

Tools: Rubber gloves, sandpaper, microwave cavity paint, cleaning solution, soap, damp cloth, dry cloth

STEP 1 Unplug the Microwave

Before exposing your microwave cavity walls to a damp cloth and soapy water, unplug the unit. Let your microwave sit for 30 minutes or longer before performing any microwave repair or service to let it completely discharge. Be especially careful if you notice electrical issues like your microwave starting with the door closed.

STEP 2 Clean the Rust Spots

Use a soapy bowl of water and a clean cloth to wash away any food particles or stains. Then, use a clean cloth to dry the cavity metal.

STEP 3 Use Sandpaper to Clear Surface Rust

Use sandpaper to smooth out the rust damage and paint chips. You can also use a flat metal tool or a metal brush to clean the rusted surface.

STEP 4 Clean the Sanded Areas

Use a cloth to wipe away any debris from the rust spots, and let the microwave dry with the door open.

STEP 5 Prep the Microwave for Paint

Do one more pass with a dry rag to ensure your microwave is free from all debris and ready to paint. You can also consider going over the microwave with 90+% alcohol and letting it dry.

STEP 6Paint the Microwave

Microwave cavity paint is usually enamel-based. In addition, you can use appliance-safe spray paint. Lastly, make sure to take breaks so each coat of paint can dry.

STEP 7 Let the Paint Dry

Leave the microwave door open for 24 hours to make sure the paint is dry.


Do not run your microwave oven if you notice rust spots. The rust can arc and cause electrical damage or a fire.


What Is microwave paint, and why is it important?

Microwave paint is an enamel paint product for use on appliances. It won’t react to microwave radiation and keeps the interior of your microwave from arcing. Peeling paint and rust can also contaminate your food, so cleaning the rust and coating it with microwave paint will prevent this.

What is the average life expectancy of a microwave?

The average lifespan of a microwave is 7 to10 years. So, if your microwave is older and suffering from stubborn stains and rusty spots, consider replacing it.

How to prevent rust formation inside a microwave?

Even if you only heat a cup of water, microwave rays produce a ton of moisture. So, if you’ve recently cooked or cleaned your microwave with a wet cloth, let it dry. Leave the door open to allow any water to evaporate.

STAT: According to a US Department of Energy survey, 3 percent of respondents in the northern mountain region of America reported owning a microwave. (source)

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