WoodDigest.com |

Water-based UV finishes have only been around for about 10 years, but they are starting to make a real impact in the wood finishes market. The obvious advantage of water-based UV finishes is the coating is very easy to apply. The viscosity and film build can easily be adjusted by the addition of water to the system.

When one thinks of “100% solids,” you might think of something like a brick or a rock or something without any liquid in it. When finishing people talk about “100% solids,” they are talking about a coating or finish that is liquid at room temperature, but when it is applied to the substrate and cured, it will not emit solvent or water. The finish has no solvent and is essentially zero VOC. The finish reacts on the surface of the part to create a solid coating on the surface of the substrate with little or no loss of weight.

It is slightly inaccurate in talking about these coatings as “100% solids UV” since there is some volatile content in the coating from additives and impurities; these potentially volatile contents may amount to about 0.1 to 0.4 lbs. per gal. of VOC.

The wood cabinet and moulding industries have long had to compromise the “look” of UV finishes vs. the VOC benefits. The coatings industry has focused on adding solvent to the UV clear coating to give a “lacquer look” — and some of these finishes had from 34 to 65 percent solvent in them. These solvent-based UV, or dual-cure finishes as some companies called them, did little to help the wood finishing industry other than helping it meet compliance for a short while. The VOC range of these solvent-diluted UV products could range from 2.8 lbs. per gal. to over 5.0 lbs. per gal. This may have been an improvement over some lacquers and conversion varnishes, but it did not solve the problem of VOC compliance for most manufacturers in the long run.

These coatings also didn’t thrill insurance companies that were worried about the potential for a catastrophic loss at the facilities in the event of a solvent-related fire.

One potential solution to VOC problems, says Craig Martin, vice president of Mid-America Protective Coatings, a UV and water-based coatings manufacturer, is the new water-based UV coatings.

“Water-based UV coatings provide the cabinet and furniture manufacturer with a near zero VOC coating that gives the look of a conversion varnish or dual-cure UV — without all the hazards of the solvent-based technologies,” Martin says. “Many of our customers can use water-based UV topcoats and immediately reduce their VOCs without sacrificing performance properties.”