Choosing the Right Preventive Coating for Metals

rust prevention

Metal corrosion is the chemical or electrochemical reactions that occur between metals and the environment. This reaction causes a negative effect on the metal’s surface properties. One way to prevent corrosion, or rust, is to apply some form of corrosion resistant coating on metal.

However, before utilising any kind of corrosion resistant coating, we first need to understand the types of metal corrosion and their contributing properties:

Fretting Corrosion

This type of rusting is visible through pits, grooves, and debris relating to oxidation. It occurs at the peaks of contact surfaces. The cause of this is usually vibration that is the result of load in the presence of repeated relative motion.

Galvanic

Can be seen as pits, holes, and oxidation and is the result of localised corrosion between two different metals that happen to meet. Usually, one metal corrodes faster while the second metal corrodes more slowly.

Uniform

As the term implies, rust is manifested by uniform and measurable material loss over a large surface area that continues until the metal is eaten up. This is the typical type of corrosion commonly seen in junkyards.

Pitting

A localised form of corrosion and is often difficult to detect. This type of corrosion is considered more dangerous to plan against. Pitting corrosion is started by localised chemical or mechanical damage of protective oxide films or non-metallic inclusions. One example of this is when batteries are left inside a torch for an extended period of time and said torch remains unused during that time. Corrosion will start to occur as a result of the batteries’ decay and subsequent contact with the metal inside the torch.

Other minor types of corrosion that are much rarer are intergranular, exfoliation, stress corrosion, and hydrogen embrittlement. But all these can result in the localised cracking of the metal, severe loss in ductility, and increased residual tensile stress.

Are there environmental factors to consider before choosing the best protective rust prevention coating?

Observe the environment and consider temperature, chemical and atmospheric conditions, and time of exposure to the elements. It’s one thing to find a good rust prevention coating, but it’s another to create a real impenetrable barrier. This also means creating surface porosity. In the case of paints, the thicker the coating, the better the permeation strength. However, in the case of flexible polyvinyl chloride copolymer solution coatings, a thick coating is not necessary. All that is needed is three thin external applications for the heavy-duty membrane to work.

One of the best coatings you will find is Unituff 452 (Seal’n’Peel). Want more information? Need help with metal rust prevention and preventive coatings? Just visit Unituff at https://unituffglobal.com/.