While you can paint oil on the outside of a metal building to prevent rust, it can be a real hassle because the oil will not stick to any area where dirt is present. Additionally, a hard rain may wash the oil away leaving the building to rust. There are other methods for stopping metal buildings from rusting that are much simpler. Here are some methods that you may want to consider.
Use Zinc
The process of applying zinc to a metal building is usually done when components are being manufactured. A process called galvanization bonds the zinc to the steel. It is highly effective often preventing rust for up to 50 years. Usually, the zinc is applied using a hot dip and binds instantly to the steel. Then, the top coat can be peeled away leaving the steel so that it will not rust.
Painting
Like oil, paint can be messy to apply. You can change the color of a metal building with paint. Choose the type of paint very carefully in order to get the best results. A polyurethane paint is the best choice to prevent rusting, and it can last for up to ten years. For steel pipes that may have more exposure to water, a longer-lasting option like paint could be best.
Thermal Spray Coatings
Thermal spray coatings can contain either zinc or aluminum. They are applied through spraying with a special paint gun that heats the zinc or aluminum to the point that it melts before it is applied. A thin coating of additional aluminum or a special coating is then blown onto the top to stop the surface from being porous. If the top layer disappears, then the building can still rust.
Acrylic Rubber
Some companies will apply an acrylic rubber to the metal building. A painter can apply the rubber in different thicknesses. One of the largest problems with this method is that no bonding occurs. It can be very difficult to get the rubber to adhere properly to the structure. Additionally, the bonding may disappear over time. Therefore, over time the acrylic rubber can wear off allowing the building to rust.
When you are buying a metal building, it is important to consider how you plan to protect it. Consider your environment and how likely it is that the building will be exposed to excess moisture. You should also consider how easy it is to create proper drainage around the building. Finally, consider if the cost of the treatment and how long it will last.