Monthly Archives: November 2009

Take That, You Sample!

The picture that accompanies this entry –no, not mine, the other one – looks a bit daffy, but the subject addresses something I’ve wondered about for a long time: UV degradation.


It's not scientific, but at least it's a test.

Admittedly, the effect of the sun’s ultraviolet – UV – rays on some sample chips isn’t a high concern of the industry today. On the science front, the radon question will generate more heat (atomic and otherwise), and there’s also the daunting task of just keeping the doors open and surviving the recession.


There’s just something about UV, though, that should keep us interested. UV rays generally leave humans and other life alone (as long as the ozone layer’s blanketing the earth), but it does the darndest things to man-made products. And, few of those results are good.

Automotive suppliers know all about UV, based on the Great Fake Wood Panel and Vinyl Top Fiasco of the late 1960s. Aficionados of that era may remember the station wagons with vinyl printed to look like wood (primarily Fords) and sedans with dimpled-feel vinyl roofs (usually General Motors). The vinyl on both looked pretty cheesy when new, but UV rays attacked the molecular structure of the material; patterns faded away, and then the vinyl lost structural integrity and flaked off.

UV still attacks cars today, and yours may be one of them. Ever notice how the inside of your windshield gets filmy at the bottom with stuff that even a Windshield Wonder® can’t take off with tap water? That’s residue from a chemical that’s used to soften the vinyl in your dashboard.

Over time, UV-laden sunshine attacks the vinyl and turns the chemical (in a process called plasticizer migration) into a gas, which then sticks on the inside of your windshield. (And you just thought it was gunk coming from the de-icer vents.)

So what’s the deal with stone and UV? Well, for one thing, nobody really talks much about how UV can affect something like quartz surfaces. That may change, as Pokarna Ltd. rolls out its Quantra quartz line with colors that include UV-resistant coating. Until now, though, it’s been a dark area.

The chips in the picture are some of Caesarstone’s 2009 new colors. After using these to illustrate a product review, I could’ve sent them off to the landfill, but I’m now conducting a very unscientific test on weathering of the material.

One half of each chip is left uncovered, while the other has a blanket of 3M Co.’s Scotchcal® reflective vinyl, which is tough stuff and extremely UV-resistant. (There’s also a undercovering of white duct tape as a final protection.)

I’ve set the chips on a shelf in the enclosed patio of my home, which is in the sunshine-and-UV-ray-rich territory of California’s Coachella Valley. They’re at 0° position – flat – and will get full exposure. Just to be fair, I’ve also set a couple of samples of Cambria’s new material on the shelf with the same preparation.

At the next StonExpo (whenever that turns out to be), I’ll strip off the vinyl and we’ll take a look at what some unadulterated sun really does to the material. You may be surprised at the result; I have a puck of Eos 3cm solid-surface that’s been in the patio for four years or so, and it’s still in one piece.

This isn’t to just pick on quartz surfaces, either. There are plenty of treatments being applied to natural-stone installations indoors and outdoors, and few are talking about UV-resistance there, either. Sunlight does have this nasty way of spilling into kitchens and onto countertops, too.

As I noted, this is purely unscientific, but it’s a test that relates far more to actual use than many of the green-based measurements and certifications now touted by manufacturers and suppliers.

Emerson Schwartzkopf

You can read up-to-the-minute news on the dimensional-stone trade and search the archives at Stone Business Online

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