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Three-Coat vs. Two-Coat Paint Systems for Buildings

April 16, 2021

More is better right? For many architects and building owners, the decision of three-coat vs. two-coat paint systems certainly isn’t black and white.

What’s the Difference? As the name implies, one system has three layers of coating (or film), and the other consists of two coating layers.

Most often, a two-coat system includes the primer and a top coat whereas three-coat systems include the primer, top coat, and a third coating (most often a clear coat) that is applied over the top.

So while the apparent difference involves the number of coating layers, there are other important differences. When the coatings are applied, two-coat systems can be produced in one pass through commercial coil coating lines, whereas three-coat systems routinely require a second pass through the coating lines.

Additionally, two-coat systems tend to be industry standard for most manufacturers, while three-coat systems are most often considered a special order. As you might guess, these last two nuances can carry both cost and lead-time implications.

Are Three-Coat Systems Necessary? For the vast majority of colors, a two-coat PVDF system of a primer and a topcoat are sufficient. There are, however, times when a three-coat PVDF system — primer, color coat and clear — coat is necessary to improve the color retention and chalk resistance of the solid color or metalescent base color.

Saturated colors like reds, oranges, and purples are good examples of colors that may benefit from the addition of a clear coat. A clear coat may also be needed for some metallic colors, like bright silvers, to protect the aluminum flake from losing its brightness and turning dark. Lastly, there are some special effect coatings available on the market that may also require three-coats; a primer, a base color coat, and an effect coating. Click here to learn more about this unique group of products. Outside of these situations (saturated colors like reds, oranges, and purple; bright silvers and special effect coatings), three-coat systems are rarely necessary nor beneficial.

In summary, the first consideration for a two-coat vs. three-coat system should center around the intended colors. Certainly, for projects involving saturated color families like purples and oranges, it may be prudent to have a three-coat system specified as the base bid.

Outside of saturated color families and bright silver metallics, most would agree that while a three-coat system might perform incrementally better than a two-coat, the differences are minimal and rarely (if ever) offset the additional project costs and lead-time.

Considering the intended color, project budget, construction schedule, desired performance, and harshness of the environment should all be considered in the decision-making process. Will these considerations make the decision miraculously black and white? Likely not. But hopefully, with a bit more knowledge about two-coat vs. three-coat systems, the decision is at least a little less gray. And if it’s not, contact us; we’re always happy to help!

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