Lacquer


Lacquer is a synthetic finish that has been the finish of choice in the furniture making industry since the 1920’s. It dries fast, has decent protective qualities, provides excellent clarity and depth, rubs out well, and is fairly easy to repair. Professionals especially appreciate lacquer’s fast drying time — 3 to 4 coats in one day is easily achieved. Lacquer is made from cellulose derived from cotton or wood fibers that is combined with a plasticizer, a resin, and a blend of solvents and diluents. The amounts and types of these materials produce lacquers with varying degrees of flexibility, color, and resistance to water, acids, alkalis, solvents, and heat.

Here are the main types of lacquer that are used for wood finishing:

Nitrocellulose lacquer

This is the most common type of lacquer. If the label on the can just says lacquer, it’s almost certainly nitrocellulose lacquer. Originally developed as a substitute for shellac, NC lacquer is attractive, sprays like a dream, and rubs out better than most other finishes. However, it yellows badly with age and only provides moderate resistance to water, heat, abrasion, and certain solvents such as alcohol.  For these reasons, it is not the best choice for a kitchen table finish, especially one made from a light-colored wood and exposed to lots of direct sunlight (unless you like the yellow look).

CAB Lacquer

CAB lacquer is typically made from a mixture of a cellulose resin called cellulose acetate butyrate (CAB) and acrylic. It is sometimes labeled as CAB-acrylic lacquer. This finish has the same general properties of nitrocellulose lacquer, except it is much whiter and yellows less over time. It also has slightly better heat resistance and is less brittle. CAB lacquer is an ideal finish for light-colored woods because it preserves the light color. However, it is more expensive and lacks some of the clarity of standard lacquer.

Catalyzed lacquer

Catalyzed lacquer is a so-called “conversion finish“. It is made from conversion varnish and nitrocellulose lacquer, resulting in an easy-to-spray, fast-drying finish with the durability and toughness of varnish.  Catalyzed lacquer requires the addition of an acid catalyst in order to cure. It can be purchased pre-catalyzed (catalyst already added) or post-catalyzed (add it yourself). Either way, once the catalyst is added, the finish has a very short shelf life so it must be used right away.
Pros (Nitrocellulose and CAB Lacquer)

  • Dries very quickly – speeds production and minimizes dust problems.
  • Easy to spray.
  • Exceptional clarity, depth, and rubbing properties.
  • Easy to remove and repair.

Cons (Nitrocellulose and CAB Lacquer)

  • Contains toxic, flammable, smelly, and air-polluting chemicals.
  • Average scratch and water vapor resistance, poor solvent and heat resistance.
  • Nitrocellulose lacquer yellows badly and may form cracks over time.

Brand Names

 

  • Behlen Stringed Instrument Lacquer
  • Deft Clear Wood Finish Brushing Lacquer
  • McFadden’s Spray Lacquer
  • Minwax Clear Brushing Lacquer
  • Oxford Ultima Spray Lacquer
  • Sherwin Williams CAB Lacquer
  • Star Clear Crackle Lacquer
  • US Cellulose Lacquers
  • Valclear CAB Acrylic Lacquer

Application

Lacquer can be brushed or sprayed on but it is usually sprayed on because it dries so quickly. To spray, first thin the lacquer according to the manufacturer’s directions. Apply the first coat, allow it to dry, and then lightly sand with 280-grit or finer sandpaper to remove any raised wood fibers. Remove the sanding dust by vacuuming, brush, tack cloth, etc. and spray on the next coat. Let this coat cure and lightly sand if there are any obvious dust nibs or other imperfections in the finish. Otherwise, just spray on the next coat. Three or four coats of lacquer will generally suffice. It isn’t necessary to let the lacquer dry completely between coats.

In order to brush lacquer, you need to either use a spraying lacquer to which you have added lacquer retarder, or buy a brushing lacquer that already contains the retarder. The retarder is a solvent that slows down the curing process, allowing you to brush on the lacquer much like shellac. The key is to work quickly and avoid going over the same area lest ye drag the lacquer and get streaks in the finish.