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Choosing a Resin-Based Coating

When it comes to coatings, the resin, or “binder,” acts as an adhesive that keeps all the elements of a paint formulation together. The resin selected is the backbone of the coating and therefore the primary source for determining the coating’s durability and physical properties. When choosing a resin-based coating, it’s important to know some of their key features.

Fluoropolymer resins are known for non-stick properties and their ability to avoid UV damage. The most well-known best performing resin in this category is Polyvinylidene Fluoride (PVDF). PVDF is at least 70 percent of the binder used in superior performance coatings, while an acrylic resin makes up the other 30 percent. PVDFs are found in coil coatings, where exceptional durability is desired. When compared to other coatings, PVDF resin-based coatings were the only coatings that did not lose their original gloss within 2-5 years.

One of the most common causes of failure for resin-based coatings is the risk of color fading. Continue reading


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Tips for Prepainted Metal Maintenance

For most buildings, the exterior is designed to be its most important eye-catching feature. While we’re wired to be extra mindful of the cleanliness and maintenance of the interior of our homes and offices, we sometimes neglect to remember to give the outside of our buildings the proper care. One of the biggest advantages of prepainted metal is its easy maintenance, but there are a few easy steps to make your metal panels shine bright.

Rinse the surface with water.

This sounds like a no-brainer, but this is one of the easiest ways to clean coated metal panels. Dirt and debris built up over time can affect the quality of the panel’s appearance and potentially reduce the lifetime of the coating. Simply rinsing the surface with a garden hose or pressure spray system will clean most buildups on a coating surface, allowing the panels to look brand new.

Clean with soap or water for difficult areas.

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Whatever Happened to … Acid Rain?

Air emissions and global warmingThis is the first in a series of posts under the general heading, “Whatever Happened to … ?” The idea is to revisit issues and opportunities of the past and help bring you up to date on what has been accomplished and what is still yet to be done. So … whatever happened to acid rain?

As it pertains to the prepainted metal market, and especially to metal roofing, acid rain became an accepted and understood phenomenon in the late 1970s and early 1980s. Badly corroded roofs were becoming more prevalent, but—like any new problem—it took some time to identify the root cause and to learn how to overcome the issue of red rusting on roofs. And, as with any root cause analysis, an early root cause declaration is usually challenged. Then more research is done, more challenges are raised, and, eventually, consensus is reached. Continue reading


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When “Just Right” Means “Uh-Oh”

nccaA while back, I wrote about the “just right” conditions necessary for the formation of fog. That particular post discussed the scattering of light, which is done by materials such as titanium dioxide (the principal pigment in white paint) and clouds (where water droplets do the scattering). The birds are chirping at sunrise and the vernal equinox has already passed, which means the sun is finally in the Northern Hemisphere and the days are getting longer and warmer—and all of this points to the beginning of another building season. That got me to thinking about a few other “just right” conditions that seem pertinent for this time of year. And, once again, water comes into play. Continue reading


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Science and ASTM

ASTM logoYou may think that that standards development in ASTM is a slow process—as it tends to be in most associations with volunteers. You may think ASTM-ers talk endlessly about the stickiness of tape or the problem with the precision of the pencil hardness test. Yes, there is plenty of that. There is also the development of new standards when new technology becomes established.

Anyone developing a piece of testing equipment in the paints and coatings industry—or the medical industry or the building and construction industry—can see the value of having an ASTM standard available to clarify its use and to describe its precision. While all of these things are important, I have found that ASTM is also the one association where science can “happen” most readily. Hard to believe? Read on! Continue reading


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The Next Great Thing: Part Two

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We left off last time mentioning two research reports, both of which discuss a functional material that might—someday—serve as a cooling device. No moving parts and no energy required to operate this device. Science fiction? Definitely not, but there is still much to be done before such a device becomes a commercial reality. But, for the moment, let’s not worry about such details.

At the 2015 CRRC Membership meeting, Aaswath Raman, Ph.D., from the Ginzton Laboratory at Stanford University, presented his work on sub-ambient cooling of sky-facing surfaces. To understand Dr. Raman’s work, picture a sheet of material with an exceptionally high solar reflectance (around 97%), mounted in a fixture on a roof in Phoenix. It has a shiny metal appearance. (Super-high reflectance is only possible with mirror-like materials.) Because the material has such a high reflectance, it will not absorb much incoming IR radiation, but it certainly will be heated by the surrounding hot desert air (convective heating). Since this shiny material is hot because of the desert heat, it is emitting plenty of IR radiation. Here is the actual installation. Continue reading


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The Next Great Thing: Part One

ImageforBlogPart1forwebIn the arena of university R&D, one often thinks, who cares? I certainly do. But in this and the next post, you will read about some fascinating work coming out of Stanford University. As a self-professed cynic, I would never mention “the next great thing” if I did not see some very real potential. There is, of course, a big valley between R&D and commercial reality, but from what I have heard and read … well, you be the judge.

One of these ideas that could fall into the “too good to be true” category is radiative cooling. Before you fear that I’ve taken leave of my senses, yes, I do understand that all objects radiate energy and will cool as a result. All cool-roofing codes contain an emittance requirement for this reason. Objects (such as painted metal roofing) with a high thermal emittance (>75%; a perfect emitter would be 100%) cool down faster than low-emittance materials such as shiny metal. When the sun sets, you want the roof to radiate as much heat as possible to the atmosphere as fast as possible. Of course, when the sun is beating down on the roof, you also want the roof to reflect as much heat as possible in the form of infrared radiation (IR), keeping the roof as cool as possible. That’s why both parameters—reflectance and emittance—are important in the cool-roofing arena. Continue reading