Surface finishing is highly important for the practical use of metals like iron and steel.
When left unprotected, these metals can quickly rust. Those colorful metals you always see are not just for decoration, but serve as functional safeguards towards rusting as well.
There are a few ways to coat metals to prevent such rust from forming, but the two main utilizations are powder coating and wet paint.
Both ultimately serve the same function (despite having some key differences): coating the bare metal with a combination of resin, additives, and pigments that prevent such corruption to increase durability.
The distinction between powder coating and paint relies on one major chemical distinction: solvent.
What is solvent?
Solvent resides in wet paint and it keeps the components of resin and additives suspended in liquid form. In contrast, powder coating is applied as a dry powder and does not contain any form of solvent, making the drying process a lot easier.
As Birmingham Al has often been called the “Steel City” it is no surprise that these powder coating facilities around the greater Birmingham area are becoming very popular.
The Application Process of Powder Coating vs. Paint
The application of powder coating or paint begins with the same process of pretreatment. Any other substance that goes against the treatment of paint such as dirt, grease, or even water hurts how the powder sticks. Thus, in the pretreatment process, any metal surface must be cleaned extremely well.
Powder Coating Application
Although the process of pretreatment remains the same, the application of powder coating differs from paint in a few ways.
The process begins with the shooting of dry powder out of an electrostatic gun. This gun places a negative charge on the powder giving it a great attraction to the grounded metal. The attraction results in a fast, even, and strong application.
The coating can range in thickness, but once the desired thickness is reached, the metal is placed in a curing oven, where powder heats and becomes a gel.
The curing process forms tight thermal bonds between powder particles creating a smooth and solid finish. It is almost like working with pottery, where heat is needed to pack the materials altogether.
This process is quite a delicate one, so professional powder coating facilities are recommended to do the process correctly.
Wet Paint Application
Wet paint is also electrostatically charged, allowing it to stick somewhat to the metal, but not as well as powder. Paint also must be put on with expert precision to avoid drips in the application process.
Some painted metal is placed in curing ovens, while most air dries to achieve the desired finish. Wet paint may also include multiple coats and a clear top coat to create the most effective thickness.
Performance of Powder Coating vs. Paint
While the application processes of powder coating and paint is important, the most important characteristic of these is the amount of protection each provides.
Powder coating provides better performance than wet paint. Due to powder coating’s ability to be applied in many thick layers, as well as the enhancement of thermal bonding in the curing process, it is incredibly more resistant to chipping and weather. Through this, it also provides great color retention.
Too much exposure to rain, heat, or moisture can cause a process of chalking to occur. Chalking is when resin and pigment particles lose their ability to stick, producing a chalk-like texture on the surface of the metal.
An increase in chalk enhances the increase of rust. That is why polyester based powder coatings are frequently used as top coats, because of their exceptional chalk prevention.
Safety and Cost of Powder Coating vs. Paint
Powder coating is not only more durable than wet paint, it is also safer and cheaper overall. This is especially true in Birmingham Al, as many companies flock to the long term sustainability of powder over paint.
Wet paint emits VOCs, which are volatile organic compounds. These are a major source of industrial pollution. Also too much exposure to such VOCs can cause increased respiratory issues, as well as major health problems.
VOCs are a major issue among businesses who utilize heavy amounts of liquid paint or chemicals. In 2017 Virginia-based Lumber Liquidators agreed to pay $36 Million to settle 2 class-action lawsuits accusing the company of selling laminate flooring containing dangerous levels of VOCs.
Since powders do not contain liquids to evaporate, they do not possess VOCs, placing them at a much lower risk and at an incredibly safe utilization rate.
Wet paint is typically cheaper than powder coating at the upfront. The powder is often made of better materials and requires a deeper process of application, giving it a greater upfront cost. Yet, the savings of powder coating, although not initially seen, quickly add up.
Unlike wet paint, powder can be collected and even reused. 70% of liquid paint is lost to overspray in the application process. This is drastically in contrast to powder coating, where the material loss can be contained to under 5%.
Wet paint, due to the weak environmental protection, requires more investment in upkeep and insurance measures. A lot of the time, multiple repaints are necessary, causing even more expenses.
Powder Coating vs. Paint
Overall, powder coating presents a greater quality, at a lower cost, to produce the best long lasting protection for metal materials. More and more powder coating companies are popping up because of the overwhelming success rate it has.
While liquid paint will always have a role in the market, powder coating is becoming highly popular not only in Birminham Al, but across the country.