What Are the Conditions Necessary For Rusting to Occur?

You probably all know what rust is; it’s that annoying reddish-brown stuff that appears on your bikes, cars, and knives. But what causes rust and can learning the answer help you prevent it? Will it grow on just about anything or do the conditions have to be just right?

If you want to find the answers to all these questions and more, keep on reading.

Conditions Necessary For Rusting

Rust, or iron oxide, is a pretty common compound and it usually appears as a reddish coating on iron or steel. It’s a naturally occurring phenomenon that happens every time iron is exposed to oxygen and water.

You’ll see rust because iron and oxygen have opposite charges and they are attracted to one another. So they look for every opportunity to bond. Even though rust is considered to be an oxidation reaction, not all iron oxides are rust by default.

Essentially, just combining iron with oxygen won’t do much if the air is dry. There needs to be some moisture or water in it for the metal to begin rusting.

While oxygen and water are really all it takes for your favorite tool, bike, or car to rust, there are some things that can make the situation worse. For example, salt, or salt water to be more exact, exacerbates the problem. If the iron or steel comes into contact with salt water, they’ll rust much faster than usual.

Also, constant temperature changes, different chemicals and minerals, as well as acids can speed up corrosion.

Less-Known Causes for Rusting

There are also some other causes that can turn any shiny piece of steel into a piece of rusty scrap. In some cases, your iron or steel components could’ve started corroding even before they left the manufacturing plant.

Different oils and chemicals that some manufacturers use to clean the metals can cause rust. What’s more, sometimes the packaging materials such as non-treated or corrugated paper can trap moisture. In turn, all that pent-up moisture will damage steel or iron.

Some other rusting culprits include:

  • Swarf
  • Fingerprints
  • Low-quality VCIs
  • Acidic packaging

How Rusting Occurs

When water comes into contact with steel or iron, two things start happening right away. First up, water tries to bond with oxygen dioxide to create a weak carbonic acid in the air. So as the acid slowly starts forming and taking shape, the iron or steel will start dissolving.

Also, some of the water particles will start breaking down again into their component pieces, i.e., hydrogen and oxygen. Then, the oxygen that broke free, as well as the dissolved iron or steel, will bond together to create iron oxide or rust. In that process, the two components will also release electrons.

Those newly freed electrons go from the anode to the cathode and attach themselves to the iron or steel. Since salt water, acid rain, and certain chemicals are better electrolytes than water, they’ll speed up the corrosion process.

Related: Corrosion and Rusting: What Is the Difference?

Why You Have to Get Rid of Rust

Of course, rust is usually not pretty to look at, but it’s much more than just an eyesore. You should always get rid of rust as soon as you see it because it’ll weaken and destroy your metal.

First, the iron or steel will start changing colors. Depending on the type of rust, it can be red, brown, or even yellow. Then, as the iron oxide starts chipping off more of the metal, it’ll start flaking.

After a while, if left untreated, rust will completely eat away at the metal and make it fragile. Essentially, it’ll turn some of the strongest materials on Earth into some of the weakest.

How to Prevent Rust

Now that you know how rust occurs, you should learn what the best prevention methods are. With that said, the ultimate way to stop rust from destroying your tools, cookware, bikes, or cars is to keep them out of humid weather and rain.

Unfortunately, that’s not always possible, especially if you have a boat or often have to drive in wet conditions. If that’s the case, you can try putting a preventive rust coating, like the one from POR-15. You could also try doing galvanization, which consists of coating your metal with zinc to prevent it from rusting.

But if coating the metal isn’t an option, you should try to look for tools that are made from metals that won’t rust. For example, stainless steel has a high percentage of chromium in it, so it is much less likely to rust.

Regular Maintenance

When it comes to keeping rust away from your valuables, the best course of action is regular maintenance and check-ups. As soon as you’re done using your tools or driving your car, make sure you thoroughly wipe everything down.

Also, once you see any cracks or dents, take care of them right away. The longer the metal stays exposed, the faster the water and air will get to it and turn it to rust.

Essentially, it’s the same if you cut your self accidentally. If you act fast, clean the wound, and protect it, you won’t have to worry about bacteria.

Treating Rust

Let’s say the worst has happened and now you have rust; well, don’t worry, there are a couple of quick and easy DIY recipes you can try to get it off. And if all else fails, there are a few commercial products that guarantee to get rid of any oxidation.

Natural Remedies

One of the easiest and cheapest things you can try out is putting lemon juice on the rust. First, start by applying some coarse salt on the oxidation spot and rubbing it in. Then, slice a lemon in half and squeeze it over the rust. If you don’t have a lemon, lime will work just as well because of how acidic it is.

Let that lemon and salt mixture stay on for at least a few hours. After it’s done working its magic, you need to gently brush it off using a soft-bristle brush, cloth, or steel wool.

If you don’t have lemons or limes lying around, you can use baking soda to get rid of the brownish spots. Simply put some in a bowl and start pouring water in until you get a paste-like consistency. Again, you’ll want to leave it to rest for a couple of hours and then, using a brush or cloth, scrub the solution away.

But if you’re removing rust from a smaller tool, like a knife, you can use vinegar instead of lemons or baking soda. Just fill a container with white vinegar, put your tool inside, and let it soak overnight.

In the morning, using steel wool or a wire brush, scrub everything, and wash it with clean water. Of course, after trying any of these methods, make sure to dry the iron or steel before putting it in storage.

Commercial Products

If you don’t want to bother with making these home remedies, you could always go for some tried-and-true commercial products.

For example, one of the best removers out there has to be the Evapo-Rust Rust Remover. It’s water-based, non-toxic, and can get rid of any rust spot, no matter how big or small.

On the other hand, you also have the Iron Out Rust Stain Remover, which works great on tools, appliances, and even laundry. Also, the Iron Out comes in a couple of different sizes and you can get as much as 9 gallons!

Final Thoughts

As you can see, all it takes for rust to occur and start destroying your prized possessions is iron or steel, water, and air. Once those things come together to make the perfect storm, iron oxide will completely weaken and ruin the metal.

Fortunately, there’s a way for you to easily prevent oxidation, and it all starts with keeping an eye out and doing maintenance. By treating every bump and scratch immediately, your things can live a long, rust-free life.

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