Polyester Paint

Red, white, blue, green, gold, beige and brown.

When I was first in the pole building industry, these were the color choices. While they may sound rather limited, given the palette of availabilities today – it was a huge improvement over the original color – bare galvanized!

These early colors had a commonality – they were all polyester paints.

Luckily for the consumer, the quality level of available paints has improved over three decades. Today, polyester paints should in all actuality only be used as liner panels (for inside walls and ceilings). If this was actually the case, however, liner panels would only be offered in white. Because they do come in several colors, tells me folks are using them other than intended – for roofing and siding!

Polyester Painted SteelMost consumers do frankly not understand the differences between paint systems and sadly can be easily misled. Especially as, when brand new, panels with different paint system look pretty much identical.

Often this lack of understanding applies also to builders and suppliers, who should be doing the teaching in the first place. In talking with the future building owner, a builder or supplier might have the advantage of selling SMP (Silicone-Modified Polyester) against a lower price (and lesser quality) Polyester.

There are always consumers who are looking for the cheapest possible products – regardless of quality. These are the same folks who buy second hand shoes at thrift stores. I believe far more people want their hard-earned money spent on their new pole building to get them a building which will look good for the long term.

Polyesters are the “low end” of the three primary resins used for coating exterior metal products. They offer a hard, scratch-resistant finish and a wide range of gloss, but are prone to chalking when exposed to UV (ultra violet) rays. Polyesters have been greatly improved since their introduction in the 1960s, however, with higher molecular weights and longer polymeric chains which create stronger, more UV-resistant bonds.

Polyester paint systems have improved greatly over the years, but they remain the lowest tier for price and performance for coil-coated exterior metal. Scratch resistance is their strong suit. In years past polyesters were recommended for soffit, entry doors and other applications without full sun exposure. Modern polyesters can take sun better, but will never match the performance of PVDFs (Polyvinylidene Fluorides) or quality SMPs.

Polyesters generally offer a broader color spectrum than PVDFs, but the brighter and darker colors, especially reds and blues, are most prone to fade. Their tendency to chalk ranges from fair to poor.

Despite long-term fade, chalk and gloss issues, when formulated with stable pigments in light colors, polyesters offer a versatile and inexpensive coating which can look good for 10 years or more. Modern systems carry 10- or 15-year film integrity warranties, and boast of decent weathering performance results

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