Wood Finishing 101


There are an unlimited number of finishes and systems that can be applied to wood. These cover everything from a simple coat of shellac all the way to multiple step (up to 20-30 steps) furniture finishing. Luckily, in the vast majority of the general finishing industry, it is typically a stain, one or two seal coats and a topcoat.  We will discuss briefly, throughout this series of articles the most common finishes that you can expect to encounter.

         The end use of the product will determine the optimum coating that should be applied.  First of all, there are interior and exterior applications. Each of these have their own set of needs in regard to resistance and durability. For example, a house paint is designed for exposure to the weather and is made to last, hopefully, for several years.  A nitrocellulose lacquer may not last much more than a month if it was used as a house paint. On the flip side, you wouldn’t expect to put a house paint on a kitchen vanity and have it provide the look and appearance that is desired.  For this discussion, we will focus on interior products.

Types of Wood Coatings: 

Stains- NGR’s, sap stains, equalizing stains, dye stains, solvent borne spray stains, solvent borne wiping stains, solvent borne stain concentrates, waterborne spray stains, waterborne wipe stains, UV stains.

Lacquers – By definition, a lacquer is a coating which forms a film as a result of solvent evaporation. These typically have been modified to be precatalyzed nowadays. Lacquer types include: nitrocellulose, acrylic, vinyl, cellulose acetate butyrate (CAB), urethane, and waterborne. Usually, lacquers are a blend of two or more vehicles, i.e. alkyd modified nitrocellulose, acrylic/CAB, etc. Lacquers can be sealers, topcoats or a self-sealing product.

Conversion Varnishes– In the simplest terms, a conversion varnish is an acid catalyzed blend of alkyd and urea resin. However, they are most times modified with other resins to enhance dry times and/or provide better performance. They may be solvent borne or water borne.  They typically provide far better resistance properties than lacquers and thusly ALL major kitchen cabinet manufacturers use these at a minimum (some use UV curable coatings).

Paints-These may be pigmented lacquers (or lacquer hybrids) or conversion varnishes. Primers also follow this same premise.

UV Curable- These may be solvent borne, water borne or 100% solids. They may be spray applied, DRC (direct roll coat), vacuum coated or fancoated. These include stains, sealers, topcoats, fillers, and paint.

Specialty Types- Glazes (wipe and breakaway), crackle lacquer, fillers, and toners.

Up next “Where do we use Stains?”

 

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