Cabinet, Wood Finishes
for Cabinetry
From varnishes and lacquers to oils and waxes, there are myriad finishes for cabinetry that can be applied on-site under varying conditions.

When trying to determine which clear finish is best for cabinetry, there is no clear-cut answer. Experts agree that there are many things to consider when choosing a fitting finish. What is the environment like? How will the cabinetry be treated? Is there a lot of excess moisture? What about airborne contaminants? Is there a lot of natural light (i.e., UV rays)? Is drying time a factor? Is durability important or should the finished piece look like fine furniture?

From varnishes and lacquers to oils and waxes, there are myriad finishes for cabinetry that can be applied on-site under varying conditions.

The wide variety of varnishes
“Varnish is a generic term for a clear protective finish. It comes in various types, including polyurethane, alkyd and conversion varnishes,” says Roy Suttles, general sales manager for McCloskey, a division of the Valspar Architectural Coatings Group.

Varnishes can be water-based or oil-based. “The water-based varnish has a low odor, which is very important for field application. In an occupied setting, it’s a big deal,” notes Andrew Kinnen, Sherwin Williams’ architectural product manager for field-applied products. “It won’t yellow, dries quickly and is very sandable.”

“Water-based topcoats are environmentally friendly, with quick and easy water cleanup,” says Jacquelyn Ferrara, product manager for Minwax. Her company’s water-based polycrylic finish is durable, crystal clear, nonflammable and dries in about two hours. Typically, it’s applied with a synthetic bristle brush, with a light sanding in between coats.

“With the popularity of decorative water-based color stains — blues, greens, mustards, etc. — water-based finishes are growing in popularity. Their clarity when dry ensures that the color remains true and vibrant,” she adds.

Kinnen advises contractors to give today’s waterborne products a second look. “These aren’t the same products introduced 10 years ago. We acknowledge that there were some issues that had to be worked out. For a lot of applications, today’s water-based or waterborne products are the way to go.”

Oil-based polyurethane, however, is the most durable coating and would be a good choice for many kitchens. Whereas most oil-based products are slow drying, Sherwin Williams has a fast-dry oil varnish in its Wood Classics line. “The fast dry is in existence because the poly takes so long to dry and tends to bubble. This product dries much faster and can be used with a sanding sealer to make things go even quicker.” Together with the line’s fast drying stain, seal and varnish, Wood Classics can deliver a complete professional finish in about eight hours.

Compared to lacquers, which are totally different in makeup, “Polyurethane and alkyd varnishes can offer pretty good durability and are relatively easy to apply on site,” says Suttles. “They’re great for remodeling work.” You don’t have to spray these products, he continues. They are usually brushed on. Solvents are required for clean-up.

A polyurethane is basically liquid plastic that creates a laminated appearance, Suttles explains. “Polyurethane can be brittle when it ages but alkyds remain flexible as the wood contracts.”

However, water-based polyurethane is very forgiving. It dries quickly, has no odor and isn’t flammable. McCloskey’s water-based polyurethane varnish is crystal clear and is an ideal choice for lightly colored and pickled cabinets.

Oil-based varnishes tend to be amber in color, with polyurethanes more so than alkyds. “Oil-based finishes deepen over time. Many people use oil-based topcoats because of this,” Ferrara says. “The ambering adds depth and richness, particularly when applied over bare wood. When applied over a wood tone stain, the color will deepen and enhance the richness of the wood grain.”

An oil-based alkyd varnish isn’t as durable as a water- or oil-based polyurethane and wears best in a nonabrasive setting where there isn’t excess moisture. “Alkyds produce a more natural appearance,” Suttles says. “It’s an old-fashioned product, you might say, one that typically is used on fine furniture.”

The most durable finish is conversion varnish, Suttles says. “It’s a two-component finish that must be catalyzed and spray applied. Typically, it’s used in shops rather than on-site because it has to be applied in a controlled environment. You don’t see too many painting contractors using conversion varnish in the field.”

As with any two-part material, he adds, there is a pot life involved. “You only have a certain amount of time to work with conversion varnish before it gets hard. It’s very fast drying.”

You can apply varnish over painted surfaces to add protection, but bear in mind that it will change the color and many manufacturers don’t think it’s necessary. “People varnish over surfaces all day long. It adds a depth to the piece and it enhances a color to make it a little wetter or darker looking,” Suttles says. Oil-based varnishes give the paint a yellowish hue, while water-based products will stay truer to the original paint color. Always test an inconspicuous spot before applying.

Whereas most varnishes are self-sealing, many contractors prefer to use a sanding sealer as the first coat. “Sanding sealers are usually used on porous wood that has a lot of grain,” Suttles says. They raise the grain so you can sand it off and get a smooth finish. Water-based products cause more grain raising than solvent-based coatings.

Sanding sealers are less expensive than polyurethane or alkyd varnishes. They’re a fast dry, too. “They have a lot of merit because you can get in and out of job in a day,” Suttles says.

Some contractors forego the sanding sealer and stick with their varnish of choice. “I don’t recommend using an undercoat with varnish,” says Lloyd Haanstra, a project leader with Deft in Irvine, Calif. “With varnish, you should sand every coat, especially when you allow the coats to dry a little longer. The longer you let the coats dry, the more important it is to sand in between coats.”

Kinnen and Suttles recommend three coats of varnish or an undercoat of sanding sealer and two topcoats of varnish. “You can mix a sanding sealer with an alkyd or water-based polyurethane varnish,” Suttles points out, “but you would never mix the two types of varnish by choice.”

The gloss of varnish finishes spans from flat to a shiny wet look and offerings vary from manufacturer to manufacturer. Whereas most homeowners seem to equate shine with durability, all perform equally well. “Sheen levels are merely a question of personal taste and home décor,” says Ferrara. “Certain modern styles are more conducive to gloss sheens; many traditional and country styles lean toward a semi-gloss or satin sheen.”