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Mastering Lacquer Techniques Requires Right Equipment and Practice
 03/05/2008 - A contractor who specializes in painting new houses once referred to cabinet finishing as the “speed bump” he always encountered while doing interior work. In other words, he had to approach the work carefully to achieve quality results.
“You’re not trying to cover a textured sheet rock wall with oil or latex paint so 'blow and go' techniques don’t work,” he said. “You’re applying stains and lacquers to bring out the grain or special characteristics of the wood. Subsequently, while you’re trying to enhance the beauty of the wood, you’re also magnifying any mistakes you might make while applying the lacquer – spotty coverage, runs, sags, and contaminants on the finished surface.”
“A painter who has good finishing techniques, does quality cabinet work and maintains a relatively fast pace is an important asset to any contractors’ team. However, becoming a quality cabinet finisher requires patience, practice and the right equipment,” he concluded.
“Applying lacquer takes a special touch,” agrees Seth Magnuson, with Deluxe Decorators Inc. of Stillwater MN. “But learning some basic techniques and picking up a few tips can help a painter get off on the right foot.”
According to Magnuson, one of the most important steps has to be done before you even begin applying the lacquer. “You must be sure the wood surface and the adjacent floor area are clean. It’s important that the surfaces of the cabinet are wiped, vacuumed and cleaned. Dust particles and other contaminants have a way of standing out like Mt. Fuji on the surface and it can be quite labor intensive to rework if not prepared correctly.”
Also be sure the wood surface is dry because moisture turns a lacquer finish milky.
“There are two reasons why this could occur. The first reason is that the painter has not allowed the stain to dry thoroughly enough. The only way to properly fix this sort of milky finish is to strip the lacquer and stain. This is controllable so always make sure your stain has had enough dry time. The second and more common reason is atmospheric moisture entrapment. This occurs on humid days when you spray lacquer. The reaction is similar to a cold pipe in the summer heat. The high dew point creates a reaction, as the curing lacquer pulls water onto the surface thus creating the milky look. To remedy moisture entrapment you can spray a thin coat of lacquer retarder and lacquer thinner mixed 50/50 over the surface,” Magnuson says. “A uniform coat of lacquer thinner will re-wet the surface, soften the finish and release the moisture. You must do this before the lacquer has fully cured or it will be more difficult to fix. When the lacquer hardens again, it should be clearer as the moisture has been released.
Unlike oil or waterbase paints, additional coats of lacquer “melt” or soften the preceding layers and bond with them.”
It’s best not to use lacquers from different suppliers on the same project. The solids content and method of manufacturing the product could differ with each supplier. If you use different lacquers side-by-side, the gloss from the two materials may vary. Sometimes it can be very noticeable.
“It’s also important to thoroughly agitate sanding sealers, satin and semi-gloss lacquers because the flattening agents might settle to the bottom. If you don’t agitate the material, the first cabinets will be glossier than the later ones. In addition, most manufacturers do not recommend straining lacquer as the straining may increase the gloss because some of the flattening agents might be removed during the process.”
“Since you need lacquer to build up to ensure the area is covered with enough mils of protective finish, you should always sand any 90 degree hard edge on doors, drawers or boxes because lacquer cannot build on those angles. Sanding the edges helps give the lacquer a place to lay down as you smooth the edge and will help protect against failure.”
Applying Lacquer
For a high quality finish use a sprayer to apply the lacquer. Don’t try to brush or roll it on. It’ll look terrible.
There are many methods by which one can apply coatings and achieve a high quality finish. These methods vary in finish quality, speed of application, and transfer efficiency. The three most common methods for fine finish spraying are HVLP, airless, and air-assisted airless.
An HVLP sprayer provides a very fine finish and is best suited for small jobs that require an extremely fine finish and attention to detail, but because it uses very low pressure to atomize the lacquer it’s the slowest application method. For portability, most contractors use an HVLP system that feature its own compressor, multi-stage turbine and filtration system.
When speed is important, airless sprayers provide the best option. Converting an airless sprayer to apply lacquer is accomplished by using a fine finish kit. This kit includes an airless spray gun with a fine mesh filter and a fine finish tip. The fine finish tip comes in smaller sizes than standard latex tips, reducing the flow rate of the material as well as the width of the spray fan. Fine finish tips also feature a pre-orifice, which produces finer atomization resulting in an improved finish quality.
Airless spraying with a fine finish kit is suited for contractors who need to apply quality finishes over large surface areas – large cabinets, walls, floors and ceilings and where overspray is not a significant concern.
Air-assisted airless sprayers combine the benefits of the airless high production rate with the control and quality finish of HVLP. Material is delivered to the gun at a pressure lower than traditional airless (usually 500-1000 psi) and is partially atomized through an airless tip. Full atomization is achieved by adding a small amount of air (5-30 psi) to the edges of the spray fan. The result is a finish that is higher in quality than airless. Its lower pressure also results in less overspray.
Air-assisted airless is ideal for medium sized surfaces such as doors, cabinets and custom woodwork. It’s the type of system used by many cabinet and furniture manufacturers. These systems can comply with HVLP compliant regulations if set up properly.
Two final suggestions about spray equipment — a good lacquer sprayer should feature a pump with pressure control capabilities with little or no “deadband” pressure fluctuation, allowing the painter to reduce fluid pressure for optimum finish quality and production. It’s also best to use a dedicated sprayer – or at least a dedicated hose and gun - to apply the lacquer because it assures the painter that the previous user of the unit did not use it to apply red paint and then neglect to properly clean the sprayer. There is nothing more disheartening than to have a red or green tint to your lacquer or to find dried paint specks in the finish!
One final note — lacquer and its vapors are very flammable. It’s extremely important to prepare the spray area properly by extinguishing all flames (pilot lights, cigarettes, etc), unplug any electrical equipment, properly ground your sprayer, and be sure the entire area is very well ventilated with fresh air. Read and follow the safety information that accompanies the spray and the material you’re spraying.
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