One of the most complex types of damage your aircraft can suffer from is corrosion. Corrosion is rust that appears on the metal surfaces and components of your aircraft. If left unchecked, corrosion can build up further, and leaving it untreated can lead to the structural deterioration of your aircraft and its parts. Repair of this type of impairment is increasingly costly and can also result in significant safety risks and loss of airworthiness for your aircraft.
Aircrafts are a big investment, not just in terms of the cost of buying them but also the other expenses that you may have to pay in the future. The regular maintenance of your aircraft helps avoid unnecessary repair costs that will be required later if the problem is left unchecked or escalates. Rust and corrosion prevention is the biggest challenge an aircraft maintenance crew faces. Thus, having the right set of knowledge and experience is crucial to keep your aircraft rust-free.
Read this post to learn more about how aircraft corrosion occurs and what forms it takes, so you have a better understanding of how to prevent it.
How Does Corrosion Occur?
An unprotected metal coming into contact with atmospheric oxygen leads to corrosion. Various factors can accelerate aircraft corrosion, such as high levels of moisture in the air, exposure to acid and pollutants, and poor preparation before paintwork. Rust may look different depending on the metal that is affected. For instance, it can appear reddish-brown on ferrous metals such as steel and grayish-white on aluminum.
It can also occur on an aircraft’s surface or in more hidden areas. Therefore, you must perform a thorough inspection of the machine regularly. Metal components of your aircraft that commonly rust or corrode include propellers, fuel tanks, cylinder fins, battery boxes, and piano-type control hinges. If you're in Edmonton, Alberta, you can hire our team of professionals for affordable aircraft maintenance services.
Dissimilar Metal Corrosion
A galvanic action, somewhat similar to electroplating, may occur in areas or points of contact between two metal surfaces of your aircraft. This happens when the insulation between the two surfaces breaks down or is omitted. This electrochemical attack can be extremely damaging in many situations. This is because of its potential to go undetected as the action takes place out of sight. The only way you can detect it before any structural failure is by disassembly and thorough inspection.
It can also be induced if your aircraft’s metal surface is contaminated by mechanical means. This includes improper use of steel cleaning products like steel wire brushes or steel wool on aluminum or magnesium. This can lodge small pieces of steel in the metal being cleaned, which can result in corrosion and ruining the adjoining surface. Careful monitoring of the use of nonwoven abrasive pads is required to ensure that different pads are used on each type of metal surface.
Filiform Corrosion
It is a special form of oxygen concentration cell that mainly occurs on your aircraft’s metal surfaces with an organic coating system. It is easy to recognize as it has a characteristic worm-like trace of corrosion or rust products beneath the paint film. One surface that is especially susceptible to this type of corrosion is one that has polyurethane finishes. Filiform corrosion occurs when the surface is slightly acidic, and the relative humidity level of the air is between 78 to 90 percent.
Steel and aluminum surfaces are usually affected by this type of corrosion. The traces cross under one another on aluminum, causing more severe damage for aluminum. Failure to remove corrosion, leaving the area untreated, and not applying a protective finish can aggravate the situation at hand, especially at seaman and around fasteners.
Keeping your aircraft in a low relative humid environment (below 70 percent) can help prevent filiform corrosion. You can also use a coating system with a low rate of oxygen and water vapor diffusion and by washing your aircraft to remove acidic air contaminants from its surface.
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Acorn Welding is a trusted and highly qualified aviation welding company in Edmonton. We have the latest product designs and manufacturing capabilities required for safe aircraft welding. To get the most reliable and best services related to aviation welding, contact us today.
