How To Remove Rust From Cast Iron Grates? (5 Step Guide)

Cast iron grills and grates are one of the most popular choices for barbecuing and grilling, and it’s easy to see why. They are incredibly versatile and durable, and when looked after correctly they can outlast more modern materials due to their toughness and quality.

Cast iron grills retain and disperse heat incredibly well and are resilient to almost all types of damage apart from one, and that’s rusting.

Unlike modern alloys like stainless steel, cast iron is vulnerable to rusting, which can turn a perfectly good grill into something that looks like it belongs on the scrap heap.

This is a shame as cast iron grills are often salvageable, and even a rusted grill that looks worse for wear can be cleaned up and get back to grilling with the right care and attention.

In this guide, we’re going to look at how you can repair a grill that has rusted over, using simple equipment and a step-by-step guide to ensure that anyone can bring their grill back from the brink.

Whether it’s been left out in the winter or simply started to rust due to its age and lack of use, it’s amazing how a few simple steps can make a grill look as good as new, and is a testament to how strong and long-lasting a quality cast iron grill can be.

But to start with, let’s take a look at what you’ll need to make this process as smooth as your grill should be.

Preparations and Equipment

While it sounds like an intensive process, rust removal is actually relatively simple and only requires a few general-purpose household items to get really amazing results.

To complete this process, you’ll need;

  • Vinegar
  • Soapy water
  • Baking soda
  • A steel brush/Steel wool pad/scraper

This is really all you need, but you can have a few optional extras on hand to make things even easier, such as;

  • Oven cleaner
  • Vegetable oil
  • Trash bags

Ensure that your soapy water is warm but not too hot as this will make using it uncomfortable.

This is really all you need, so now we can move on to the step-by-step guide on how to actually remove the rust from your beloved grill!

Step by Step Removal

As mentioned before, the process for removing rust from your grill isn’t anywhere near as complex and difficult as it sounds, and it’s mostly a case of some elbow grease and the right tools being used to make the job painless and easy.

While there can be some differences depending on the size of your grill and the extent to which it has been rusted over, most grills can be salvaged following these steps.

Only grills that are literally falling apart from rust and warping out of shape/losing structural integrity are too far gone to be salvaged most of the time.

But let’s get started;

Step 1  -Wash the Grill or Grate in Warm Water

An initial wash in warm soapy water is a great way to start the process of cleaning your grate, as the soap will attack any loose muck and grease and help to start the process of loosening and weakening the rust and other filth which is coating your grate.

This helps to remove excess grease as well as food and dirt and will make the later steps much more effective. 

Soak the grill well and use a wire brush or pad to scrub off as much of the debris you can without worrying about getting everything. Just give it a good once over and focus on the more general dirt, as later steps will handle the rust itself.

Step 2 – Soak the Grate in Vinegar and Baking Soda

Prepare to soak the grate by mixing a solution of vinegar and baking soda in a clean bowl or bucket that is capable of fully immersing the grate.

This is important because the mixture needs to be able to totally cover the grate in order to fully work on removing the rust.

Once the mixture is made the grill should be immersed inside this mixture, and left in it for as long as possible, ideally overnight or for at least an hour or two depending on the amount of rust that is covering the grate.

If the rust is particularly deep or widespread sometimes a multi-day soak is required.

This will allow the mixture to penetrate the rust and soften it to the point where even the most stubborn parts of it will be removable in the following steps.

Step 3 – Use Oven Cleaner

If the rust is still too stubborn and isn’t responding well to the above mixture, it’s time to try using oven cleaner. 

This chemical will provide an even deeper clean, however, it’s a very harsh chemical so precautions should be taken when using it.

Use it only in a well-ventilated area, spraying just enough to cover the grate and coat it. Put the grate into a sealable trash bag and close it tightly/seal it.

Then put this in a container or safe place. Keep everything away from light, heat, children, and pets. After a day or two, you can take the grate out of the bag and rinse it off with water which should reveal a much cleaner and easier to scrub grate.

If there are any spots remaining, scrub with a wire brush as before taking care to not get oven cleaner on you or other possessions.

Step 4 – Dry the Grate

Drying the grate is critically important as any moisture allowed to remain on the grate will begin the rusting process again.

Once all agents and chemicals have been removed from the grate with water you can dry the worst of the remaining water off with paper towels, then heat the grate in an oven on low heat to bake off any remaining moisture.

Step 5 – Treat the Grate

Now the grates are rust-free and dry, it’s time to make sure they’re ready for grilling again!

The first thing to do is to heat the grills up to a temperature of between 300 degrees Fahrenheit (149 degrees Celsius) to 400 degrees Fahrenheit (205 degrees Celsius).

Apply some vegetable oil to the grates ensuring that they are comprehensively covered, and continue applying the oil every half an hour or so until the grates are blackened and shiny like a healthy grill should be.

This will ensure that they don’t rust up again as oil repels water and moisture that will appear during grilling, and this will also prevent food from sticking to the grill so easily and making it dirty.

Rust Prevention

Now that your grill is clean and looking as good as new, it’s a good idea to make sure you can prevent needing to go through this process again for a long while as it can be a little bit of a chore to say the least.

There are a few things you can to do prevent rust build up such as;

Cleaning grates after use – Allowing excess food and sauce to build up on a grill grate is a sure way to attract filth and degrade the finish of your grill which will eventually leave it exposed to water and rust formation.

Ensuring that no leftovers are left on your grill after use or cleaning is the best way to prevent rust build-up.

Another thing you can do is use oil every time you cook to both prevent moisture and steam from impregnating the grate and penetrating into the cast iron beneath, and this has the bonus of also preventing food from sticking to the grate so easily preventing filth and dirt building up.

If your grill is looking dry or tired it’s time to re-season the grill to seal up the iron and protect it from water, by sealing it in oil

Seasoning the grill is really important to protect the longevity of your grill, and to do this all you need to do is ensure the grill is clean.

Then repeat step 5 of the step by step guide above which will coat the grate in oil and give it that moist, greasy, oiling covering that protects that cast iron beneath from rust and moisture in the long term.

Final Thoughts

Overall, a cast iron grill is an excellent way to cook your food and it’s something that is becoming popular again as modern grill grates simply don’t last as long or provide as high-quality heat dispersion.

As long as you take care of your grill, it will take care of you, so follow these steps to ensure it continues to cook well into your future and gives you the best value possible.