Does Magnesium Rust?

There is no rusting in the magnesium because it has its inherent qualities. As one of the strongest metals on earth, magnesium has been used in manufacturing cars and airplanes to create product packaging. Magnesium oxide (MgO) is also used as a building material and fire protection products.  but does magnesium rust? 

No, Magnesium will not rust in cold water, but it can corrode and weaken when exposed to saltwater, acids, and bases. Magnesium itself does not rust. However, the surface of magnesium can corrode in moist air, similar to aluminum.

Also, because it does not rust easily, it is used for aerospace and aircraft applications. It has the strength to resist corrosion for long periods, even at high temperatures. Magnesium alloys became the material of choice in the aerospace industry because of their high strength-to-weight ratio, improved stiffness, and ductility in comparison to other materials such as steel and aluminum.

While it is said that it does not rust, it can corrode, and with the information below, you can easily find the easiest way to prevent magnesium from future corrosion

How To Prevent Magnesium From Corrosion

Magnesium products are secured against corrosion when coated with a protective layer that creates a barrier between the magnesium product itself and oxidation elements. Coatings protect magnesium from moisture and are essential for keeping the items free of corrosion. Here are some coatings that can be used for magnesium.

How To Prevent Magnesium From Corrosion


An excellent way to prevent magnesium from rusting is by painting it. Before you paint your magnesium item, ensure that you clean it properly. The cleaning process is essential to have an effective result from painting it. If your item or equipment made of magnesium is not properly cleaned before it is painted, the paint will not sit properly on it, and your effort and money will be wasted. Part of the cleaning process is degreasing the item. Cleaners containing strong alkaline are recommended for cleaning magnesium products. This is because magnesium is alkali resistant.


Deoxidising the product is another way to pretreat it before painting. To deoxidize the product, you can give it a blast cleaning with a high-pressure hose. This method is tricky in a way because it can shift oily substances to the surface of the product. Therefore, it is advisable to degrease the equipment or tool before blast cleaning it. Another method to explore is using chromic acid.


Priming is another pretreating process before painting it. Using a primer designated for magnesium items is preferable. To be on the safer side, it is advisable to seek professional advice on the product to buy.

After following through with these processes, you can paint the equipment or tool. When painting your equipment, ensure to follow the manufacturer’s instructions. Leave the paint to dry as long as is recommended. Some paints will take 45 minutes to 1 hour to get dried why some might take up to 4 hours.

Conversion coating

Conversion coating is one of the best options of protecting magnesium products from corrosion. This option is preferable compared to other coating options because it reacts with magnesium itself and becomes a part of it. There are different types of conversion coating you can explore. However, chromate conversion coating is a popular choice. Over time this coating has served its purpose effectively, so you can consider going for it.

Organic coating

If your aim is to protect your magnesium component, well, an organic coating is a great choice. There are many options of organic coating to explore, including powder resin, high-temperature coating, and so on. Magnesium is light and does not pose a threat to the environment. It is often used for coating different applications.

Oiling and greasing

Oils and greases can be applied to the surface of magnesium items to protect them from corrosion. Oils and greases a similar but different. Most greases are made from oils. Greases are usually thicker than oils when both are at room temperature. Greases are oils with thickeners. Oiling and greasing will protect your magnesium items from rust. Aside from this, they will make moving parts work better with little or no friction. Oils and greases might make using your tools challenging as it will be difficult to hold them firm. This will entail wiping off the oils and greases before using the item. Consequently, you have to apply coats of oil and grease regularly.

Tips For Coating Magnesium Products

To keep corrosion away from your magnesium item, you have to apply protective coatings to them. You only get the best result of this exercise if you go about it the right way. With the proper information, you should be doing things right. Here are some tips to help you put your magnesium products effectively:

Tips For Coating Magnesium Products

  • When coating your magnesium components, ensure that they are done properly the first time. If magnesium is used in building some parts of an application, it might not be easily accessible for a second touch-up. For instance, parts like the lavatory and seat are designed with magnesium in the aerospace industry. In the automotive industry, parts like seat and door frames and steering wheels are made with magnesium components. Getting to these parts for a recoating might not be the easiest thing to do. There, doing proper coaching with the right material is essential.
  • When applying coatings to magnesium items, ensure to make a uniform application. If some parts are emitted and some parts are too thick, the results will not be great. Also, areas with thin coating may not last as long as areas with sufficient coating.
  • Ensure to clean the magnesium item properly before coating it. If the item is greasy or dirty, the cost might not sit properly on the item. Also, if there is rust on the item already, ensure to take it off before applying the coating. If there is rust in the item before it is coated, it is only a matter of time before the rust breaks out, and you have to repeat the entire process.


Magnesium rusts when it is exposed to moisture and air. However, you can protect your magnesium applications from rust with protective coatings. The tips listed above will help you keep your equipment, tools, and parts more effectively.

Evan Cooper

Evan Cooper

Hi, I’m Evan Cooper, the founder and an editor of this site, Doesitrust. I’m a chemical engineer and working in a rust-eliminating paint manufacturing company. Besides this profession, I’m a researcher and blogger.

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