Ultraviolet (UV) technology has become a buzzword of sorts in the automotive industry. The technology has been used in the
automotive industry for years, on the manufacturing side, mainly in the production of headlamps. Its extreme scratch resistance
makes it a perfect fit for protective headlamp lenses and dash bezels. The application of UV and its acceptance in the collision industry has been a little more tenuous. Initial testing began years
ago, but there were issues that had to be overcome. Today, the technology has improved to the point that it can be a viable
option to handle small, usually one-panel, repairs. While it may not yet be the best choice for large repairs, or overall
refinishing, this technology is promising due to its ability to significantly cut cycle times. It is possible to fix a small
ding or scratch, prime, and paint the repaired panel, and deliver the car using UV in less than one hour. For this reason,
plenty of interested shop owners and managers are looking more closely at the UV process. You should too.
The basics
UV curing works through a chemical process, activated by the energy of ultraviolet light. The light crosslinks (cures) liquid
product molecules, and "force" dries the product in less than one minute. Unlike chemically or heat-cured finishes, UV-cured
surfaces dry extremely quickly, to the point they can be worked with, in minutes, including buffing. Even though the UV paint curing process is much faster than drying conventional paints with IRT technology, or using the bake
cycle on a booth, there is virtually no risk of deforming or melting plastic parts such as bumper covers or trim pieces due
to high temperatures. UV lamps do generate a small amount of heat. If the lamp is positioned correctly on the surface being
dried, any heat produced will be minor and certainly not enough to cause damage.
Product availability
In general, there is a limited number of UV-cured products currently available in the market. These include primers, aerosols
and sprayables, putties (used for minor repair) and clear coats. There are no UV basecoats available for automotive applications
at this time. Each of these products typically is part of a one component, or non-catalyzed system, so they have an extended
shelf life (1-2 years).
The most common and readily available product is the aerosol UV-cured primer. It is easy to use and has become a favorite
product for painters at Collision Centers of America. I interviewed several painters at their high volume, Schiller Park location,
where speed and quality are extremely important. Matt Wagner, head painter there, said, "I can prime a small spot, hit it
with the light, and scuff it in minutes. It really speeds up the cycle time on small jobs, to a point where it's almost unbelievable."
In this facility, they do a great many drivable, smaller repairs that fit well with the qualities that UV can provide.
These primers are available from a number of manufacturers. Since the primer is in an aerosol can, it is really easy to use
anywhere in the shop. An added benefit is that the overspray is safer, and without activation from a UV light source, can
almost be wiped off anything it hits with a clean rag. Some manufacturers do make a primer that can be sprayed with a conventional
gun, so that larger areas can be primed as well. Ask your jobbers about what lines they carry and experiment.
Glazing putty
UV glazing putties are used primarily to fill small surface imperfections in vehicle panels and can be used over polyester
body fillers. They are usually compatible with most brands of automotive primers and sealers. As long as UV glazing putties
are not exposed to light, their shelf life can be as long as one or two years. Some putties are not pigmented and are essentially
clear. They work well due to the fact that the UV rays can penetrate the entire product completely through, offering a more
thorough and faster dry time.
These putties are not high build and will fill only small imperfections. As with the primers, once they are exposed to the
rays of a UV light source, they dry without being mixed with any hardener. In a minute, they're ready to sand. They tend to
sand well, although if not cured properly, they will roll up like uncured filler does. Following the manufacturers' directions
is imperative. The putty is applied with a standard or rubber spreader. Do not put the product on too thickly. Apply it as
you would a standard polyester glazing putty. Once it is applied, position the UV lamp over the repair area. In about a minute,
the putty will cure and be ready to sand.