Corrosion is one of the most notorious causes of deterioration in metal surfaces. If you want to preserve and extend the integrity and usefulness of your metal equipment, then you should consider applying a coating designed to protect against corrosion.
Understanding rust
Metal corrosion can occur in several ways, the most common of which is through rusting. Rust is a common term for different varieties of iron oxide, which form when iron is exposed to oxygen in the presence of water or moisture in the air. Iron oxide may also form in iron alloys, including steel.
Rust degrades metal, reducing its durability and ductility. Rusted equipment cannot hold as much weight as it used to and rusted joints lose much of their mobility. Furthermore, although rust in itself is non-toxic, rusted surfaces may harbor bacteria that cause tetanus. These microorganisms enter the bloodstream when rusty surfaces break the skin and, when untreated, can cause death.
Corrosion costs the world over $2.5 trillion every year. Part of this cost goes to restoring rusted surfaces, which is a pricey endeavor. This is partly why many business owners opt to simply replace their equipment once rust has begun to compromise its performance and the safety of its users.
Protecting equipment from rust
When it comes to resolving corrosion, prevention is the best course of action. Two approaches often taken for this purpose involve the use of:
- Sacrificial metals – This involves the use of a layer of metal, such as magnesium or zinc, placed over steel or some other metal surface that needs to be protected. Upon exposure to the environment, the sacrificial layer corrodes, but prevents the surface underneath from deteriorating. This effect can be achieved by applying zinc-rich coatings, which consist of 85 to 95 percent zinc, on steel surfaces.
- Primers – Besides improving the adhesion of topcoats, primers also act as a protective layer that separates metal from water and oxygen that cause rusting. Some primers also absorb moisture and prevent it from making contact with the metal underneath. Certain primers may even contain pigments that alter the base properties of the surface metal and reduce its potential for rusting.
Using coatings to prevent rusting
There are three types of coatings that can protect metal surfaces from rust:
#1. Alkyd enamels
These coatings are often used as topcoats and perform excellently whether they’re used for indoor or outdoor applications. They form a solid, high-gloss, and fade-resistant layer that effectively protects base metals from environmental factors. This layer can last anywhere from three to five years.
#2. Epoxy coatings
Unlike alkyd enamel coatings, epoxy coatings are not glossy and do not retain their colors well. They are, however, very sturdy and can withstand harsh conditions. Because of these characteristics, they are often used in both indoor and outdoor industrial settings where function matters more than appearance does.
#3. Polyurethane coatings
This type of coating combines the best qualities of alkyd enamel and epoxy coatings. Besides being high-gloss, it is also resistant to both fading and abrasion. Even when exposed to severe industrial conditions, polyurethane coatings can last up to 10 years.
But just because polyurethane coatings have excellent characteristics doesn’t mean it’s ideal for your intended use. For one, it is not recommended for surfaces that are exposed to constant and intense sunlight.
You also need to take a number of factors into account when making your choice. These include your budget, the look you want for your equipment, and the environmental regulations implemented in your area. You also have to consider the application method required. For instance, polyurethane is usually sprayed, while epoxy coatings can be applied using a brush, roller, or spray.
If you are unsure of which coating suits your project best, you can always seek the guidance of the experts at Mobile Paint. You may also ask them to formulate a coating that provides your desired level of gloss or durability, or other characteristics, for that matter. Call us today to get started!