Throughout my years of selling products to hardwood flooring professionals, I have found most are looking constantly for a way to better their game or figure out any way they can differentiate themselves from the competition. Some made the switch to water-based finishes years ago when the rest of their market was still doing solvent finishes. Another opportunity was providing dust containment, where now almost everyone has some type of vacuum on the jobsite to aid in minimizing the dust. Others learned the ins-and-outs of the penetrating oils and started providing additional layering options that can provide unique looks and colors that were otherwise previously unattainable.
While ultraviolet (UV) cured products are not new to the hardwood flooring industry, site finished UV cured products are continuing to gain in popularity, and, once again, providing you another way to differentiate your company from the competition, and even better, provide an additional industry to utilize the investment in equipment. Here are a couple of things that make UV cured finishes unique.
An on-site UV cured finish is a transparent, water-carried polyurethane that provides exceptional durability, easy application, self-leveling, and great adhesion qualities, which can be used residentially or commercially with the added benefit of being able to be cured instantly. These finishes are available in different gloss levels, from matte to gloss, similar to other waterborne finishes. They have a very mild odor, which will dissipate after the finish has dried.
UV cured finishes are one-component finishes that contain synthetic resins, plasticizers, urethane, acrylic or blends and a photo-initiator. When exposed to high-intensity UV light, the photo-initiator triggers a chemical crosslinking reaction within the polymer (similar to that of a two-component finish), which cures the film. Cure time is instantaneous once the UV lights react with the photo initiators. Desired finish properties like durability, sheen, and chemical resistance are achieved immediately.
UV Cured Finishes Can be Categorized in Two Classes:
Waterborne UV Curable Finishes
Waterborne UV curable finishes contain water as a solvent and dry to the touch by evaporation. The application of the finish is the same as most other waterborne finishes and usually is dry to the touch in two to four hours. The difference is the curing process. The water in that film must be evaporated completely prior to starting the curing process. The uncured dry film is somewhat soft, but will withstand the UV curing equipment and light foot traffic. Curing happens when the dry film is exposed to the UV light. Once it is exposed, it is cured, and it can either be abraded for an additional coat or put into immediate use by the floor owner.
100 Percent Solids UV Finishes
100 percent solids UV finishes are a liquid coating that consists completely of solids and reacts to polymerize upon exposure to a specific spectrum of light. As the wet finish is exposed to the UV light, it changes from liquid to solid (film). The coating cures without any difference in wet mil to dry mil thickness. These finishes have a quick build, with no wait time for water to evaporate. 100 percent solids UV finishes are coated, then dried by use of UV light while the finish is still in a wet state. There can be a risk of leaving footprints or tracks behind in the wet finish if not cured properly.
UV cured finishes are one-component finishes that contain synthetic resins, plasticizers, urethane, acrylic or blends and a photo-initiator. When exposed to high intensity UV light, the photo-initiator triggers a chemical crosslinking reaction within the polymer (similar to that of a two-component finish), which cures the film. Cure time is instantaneous once the UV lights react with the photo-initiators. Desired finish properties like durability, sheen, and chemical resistance are achieved immediately.
Application of UV finishes is not much different than the application methods used for other waterborne finishes. Rollers, T-bars, and cut-in-pads typically are used to apply UV finishes. Previously applied stains and finishes must be dried completely, clean, and adequately adhered to the surface prior to application of a UV finish. For best adhesion, some manufacturers may require a build coat with a traditional cure product over a stain or previously coated floor prior to the application of the UV finish. In a full sand and finish, three to four coats are recommended for UV cured finishes (which may include seal coats). These finishes do not always need to be abraded between coats. Follow manufacturer recommendations for intercoat abrasion requirements and hot-coat windows.
Safety is critical when using portable UV curing machines. Always follow the equipment manufacturer’s instructions for proper use and safety. This includes use of additional special eye and skin protection for the person curing the floor, and for bystanders/onlookers.
While there may be an initial investment in equipment to make this leap into the UV curing world, it is no different than the dust containment craze when it was first introduced. As a matter of fact, I have used the same equipment cost analysis sheets I used back in the early 2000s to sell dust containment equipment when explaining the UV opportunity to my customers.
There are hundreds of thousands of square feet of flooring that are in need of restoration that may require immediate access, not including the immediate access advantage these systems may offer your commercial or builder hardwood accounts.
Matt Thrane is a training specialist and handles new business development for Gehl Flooring Supply Inc. in Wauwatosa, Wisconsin. He can be reached at matt@gehlflooring.com.