One of the advantages of powder coatings is that they can be, and often are, a single-coat application. But there are circumstances when a primer is recommended for added corrosion protection and other benefits like better adhesion, improved edge coverage and an increased film build.
Enhancing Corrosion Protection and Performance: PPG's Breakthrough Zinc Epoxy Primer
Powder primers infused with zinc, a naturally occurring element prized for its exceptional corrosion resistance properties and durability, are among the most widely used classes of powder primers.
Within a primer, zinc acts as a barrier that shields the metal from corrosive elements, reduces its reactivity to surrounding elements and repairs damage from cracks as it has some self-healing properties.
Zinc offers excellent protection against oxidation and corrosion even in the most challenging operating environments. However, there are some notable drawbacks to standard zinc-rich formulations, primarily due to their weight and density.
Zinc particles are more dense than other components commonly used in primers. As a result, zinc-rich primers have a higher specific gravity (SG) of 3.6, a ratio based on the density of the material compared to the density of water. This weight makes them harder to apply because particles tend to fall quickly, leading to overspray and reduced efficiency compared to other powder platforms.
PPG scientists recently developed a breakthrough zinc powder primer that contains only the precise amount of zinc necessary for robust corrosion protection, but with higher transfer efficiency due to a lower SG of two. Most notably, this next generation of zinc optimized powder primers offer improved first pass build rates, 80% better coverage than traditional zinc-rich primers, and application similar to standard powders.
A testament to their durability is that these primers offer resistance after 10,000 of salt spray testing on blasted steel and 13,000 when used on conjunction with an ultra-durable polyester, according to testing using SAE J2557, ISO 12944:C5VH, ASTM G85 and coastal exposure.
This patent-pending PRIMERON® Optimal powder primer can be used in a two-coat, one-bake process on steel, hot-dip-galvanized steel, metalized steel and aluminum.
Switch-N-Go upgrades their powder primer technology
Unhappy with the finishing defects produced from a competitor’s powder primer, Switch-N-Go® was one of the first customers to trial PPG’s new optimized zinc powder primer for their interchangeable truck bodies, designed, developed and fabricated in-house at the company’s Saegertown, Pennsylvania, headquarters.
During the successful line trial, the Switch-N-Go team took notice of the premium finish with less spitting and a higher transfer efficiency that resulted in better coverage with less product, overspray and cleanup.
The company also improved their throughput and energy usage with the low-bake capability that shaved 15 degrees off their cure temperatures and 10 minutes from each cycle.
PPG’s full PRIMERON powder primer portfolio
Primeron Optimal primer is one of five products in PPG’s PRIMERON® powder primer portfolio.
This full range of high-performance primers comes with unique features, including anti-outgassing and semi-conductive properties, to meet diverse requirements across different applications, including:
- Electrical and power generation
- HVAC and appliance
- Trucks and trailers
- Automotive parts and wheel
- Gas or liquid tanks and pipelines
Primeron Legacy, PPG’s traditional zinc-rich primer that offers the best corrosion protection in this technology.
Primeron Auto, designed for layered protection in automotive specialty markets, with options for exceptional flexibility, chip and corrosion resistance, UV durability and outgassing.
Primeron Edge, offering best in class corrosion protection on substrates with sharp and laser-cut edges.
Primeron Versa, outgas-friendly, zinc-alternative primers that provide excellent corrosion protection for multiple substrates.
PPG Powder Primers meet IEEE and ISO12944 approvals, the industry benchmark for safeguarding steel structures against corrosion through protective paint systems.
Read more about Switch-N-Go’s primer upgrade and how PPG is taking primer performance to the next level for a wide range of applications. Download the case study>