When homeowners look at painted products, often it’s the color they focus on – will it have great curb appeal and match their tastes? But, at Metal Roofing Source, we know there’s more to it than being pretty, and that’s why we sell products that use Kynar, a PVDF resin-based painting system.
For metal roofs and metal panels, the paint finish is key to guarding your investment. Kynar products offer protection for decades, but they do it while looking fantastic in all kinds of beautiful colors too.
Kynar Applications – Heavy Duty Panels
Kynar coatings are usually found on metal roof panels designed for commercial application. Panels that require a heavier gauge system, such as for schools, large commercial, government, etc.
Fabral, one of our metal panel partners, uses Kynar on their Architectural line of product (commercial line). For the lighter gauge residential and light commercial (generally structures that use a wood frame construction), they use their well-known Enduracote system. The lighter gauge panels generally do not need the heavy-duty Kynar top coat. The Enduracote covering will still keep the panels looking good for a lifetime. The main difference is that the Kynar is designed for heavy duty applications vs the light-duty applications of the Enduracote covering.
Kynar or Kynar 500® is not a finished paint. It is a trade name for PVDF (polyvinylidene fluoride) resin. PVDF resin is the raw material used by licensed formulators to manufacture PVDF based coatings. When formulated into a coating composition, the paint contains a minimum of 70% by weight of Kynar 500 resin to manufacture a 70% PVDF resin based coating, that meets the highest performance criteria of AAMA – 2605.
Why Metal Panel Topcoats Matter
If you were re-painting metal patio furniture for all-season use, you’d get picky about the spray paint, right? Heck, you might even buy clearcoat to really seal the deal.
Well, it’s the same with metal roofing and exterior panels. Every building must withstand hailstorms, windblown acorns whacking against the house in a gale, and other unpredictable attacks from Mother Nature. And paint doesn’t just need to withstand impacts, it needs to fend off corrosion and rust from acid rain and seaside salt air.
You’ve seen examples of how badly paint can peel and fade. It’s on most streets, commonly happening on automobiles for all kinds of reasons. One American carmaker is legendary for paint problems, losing class-action lawsuits filed by consumers over paints peeling, fading, and chipping far too easily, far too soon. A 3-foot-round peeling patch of paint on a minivan’s hood looks bad. What if it happened to a whole roof?
Kynar-coated products don’t have those problems. We’d know by now.
In 1965, Kynar resin-based paints were first introduced as a game-changing architectural paint finish for metal panels, quickly becoming the first choice for architects and contractors throughout the industry. For over 50 years, the makers of Kynar have engineered trade-protected metal-painting compounds backed by tough warranties, because their paints have proven themselves decade after decade.
Kynar products can, and do, stand the test of time.
Paint Has Come a Long Way
Since ancient times, humans have beautified their world with paint. But the Industrial Revolution gave paint a new job – protecting things. With the rise of tin toys, automobiles, bikes and even metal advertising signs, paint had to protect metal while looking good for the long haul.
For most of history, one key ingredient made paint durable, resistant to moisture, faster to dry, and longer lasting – lead. Unfortunately, we learned heavy metal poisoning could occur with lead paint. So, in the 1970s, lead fell out of favor, got regulated, and scientists learned new ways to make paint last.
Compounds, processes, and additives used since have become guarded industry secrets, but one thing’s clear: Paint is big business. For architectural uses alone, paint is a $12 billion-per-year business. Add in cars and other products, you’re looking at over $25 billion annually.
One thing dictates a paint’s success more than any other: Durability. And it’s durability that’s a hallmark of the resin-based paint system behind Kynar.
The Science Behind Kynar Resin-Based Paints
When painting at home, you get better protection and superior color when doing at least two coats, right? Imagine the protection you get with Kynar’s six coats, then. Each coat plays a different part in protecting metal panels.
Now, trade secrets mean those layers’ specifics aren’t known to anyone outside Kynar, not even partner companies like us. But we can tell you a bit, especially about how galvanizing treatment is usually done for steel. It serves as the first “coat” over bare steel, a 100% zinc-based film that helps industrial steel products last over 50 years. It works even through long-term, severe water exposure, because rust protection is job one for galvanizing.
Except it’s not only traditional galvanizing that’s used for Kynar products. For some panels, they use the patented Galvalume process. It’s even tougher, thanks to being a zinc-aluminum alloy. Once applied, the blend of 45% zinc with 55% aluminum looks different from galvanized finishes because its visible crystals are smaller and more compacted, for a smoother finish. Most importantly, though, it’s often superior to traditional galvanizing for protection against water and corrosion, even decades later.
That protective layer used varies between Galvalume and galvanized protection depending on the type of metal panels or parts being coated.
Either way, whether the coat is galvanized or Galvalume, it’s done through process used called “hot-dipping.” It’s a multi-step process before applying the coat to steel.
First, the steel’s cleaned with a degreaser, then they “pickle” the steel by dipping it in a vat of diluted hot sulfuric acid. Pickling removes impurities like rust and scale, sort of like resetting steel to its natural state. The metal is still vulnerable to humidity in the air, since the iron in steel is prone to rusting, so the next step is to flux it. Fluxing is another kind of chemical cleaning that prevents oxidation, especially before joining metals.
“But they’re painting it,” you say. “They’re not joining metals.”
Except they sort of are joining metals, because the next step is to dip the fluxed metal into a vat of the molten alloy or zinc coating, which is the galvanizing or Galvalume layer.
This zinc-based coat is key. It protects steel by being the first line of defense. And several decades down the line, when topcoats have weakened and corrosion begins, any corrosion would attack the zinc – not the steel, because it’s the first metal the rust would hit.
The Next Layers of Protection
After the galvanizing are four more layers all designed to protect your investment. Next up is the zinc pre-treatment. What is it? The folks behind Kynar won’t say. Shh, trade secrets abound!
But take the automotive industry – zinc pre-treatments are a proven method to improve the bond for powder coating and other painted-metal finishes. It also adds more corrosion prevention, but this time it’s protecting the galvanized layer.
You’re thinking, “but the galvanizing also has zinc, so…” Indeed, but the zinc pre-treatment is their “pre-painting” preparation as opposed to coating the metal itself. It’s a different chemical process.
Picture a medieval castle. The castle represents your metal panel.
Castle walls are critical to the castle’s defense, so the walls are like your Galvalume or galvanizing. But the goal is to keep the pillaging hordes away from the wall, so they use another layer of protection – the castle’s moat, a formidable obstacle to overcome. The moat is akin to the zinc pre-treatment. So, the layers of zinc protection each operate in their own way.
Kynar adds even more protection between the elements and your investment, applying a sealant to preserve all those anti-corrosion properties. While Kynar doesn’t divulge details for the sealant, what we can tell you is, it’s effective and is part of the durable, attractive finish our clients love.
Then, It’s Paint Time!
If you’ve ever painted at home, you probably know what’s next – a primer, then the first coat of paint, or the “backer coat,” followed by the topcoat.
Now, we have no spies in the Kynar factory, so their paint recipe is a mystery. What we do know is Kynar revolutionized architectural paint in the 1960s and has remained is a leader in the metal panel industry ever since. Chances are, if you see a great-looking metal roof that’s a couple decades into its life, it’s great looking because it’s Kynar paint.
From military bases to cutting-edge net-zero constructions through to ski cabins in the mountains and bungalows in hurricane country, Kynar-coated metal panels are getting the job done – with style.
Kynar’s proprietary paint system is trusted by architects, engineers, and defense contractors. You can trust it, too.
The Lowdown on Warranties
Whether you’re cladding walls or a roof, Kynar-coated panels come with a lifetime film integrity warranty and a minimum 30-year warranty against fading and chalking.
While acid rain is much less common than it once was, thanks to the US Clean Air Act and other agreements, it’s still a problem in some areas. The edge-rust warranty against acid rust is 10 years, or 15 years if your product is offered with Galvalume Plus, another finish they use that offers further protection through an organic clearcoat on both sides of the metal.
Why Specify Kynar 500?
To be both functional and decorative, heavy-gauge metal must be coated with a finish that beautifies with color and doesn’t chalk; that won’t lose its color and sheen; that won’t pit, chip, or age before its time. No other coating system withstands the rigors of nature and time like those based on Kynar 500® resins. This high-performance fluoropolymer resin, with its extraordinary capability to retain color and gloss, keeps painted metal looking vibrant and appealing.
As a resource for architects, spec-writers and project managers, Linetec has prepared a non-proprietary CSI 3-part guide specification for superior, sustainable high-performance PVDF architectural finishes. (05-0513 Shop-Applied Coatings for Metal). This specification can be downloaded from the Architect Recourse Center of Linetec’s website
Arkema is the manufacturer of Kynar & Kynar 500 resin. Solvay is the manufacturer of Hylar 5000 resin.
Still Have Questions?
Give us a call to talk about it. We’re always happy to help.