Varnish 101: What You Need to Know About Furniture Varnishes, Lacquers & More

Enjoy the first in our new blog series featuring our Guild members and their craft. We start with Jim Backer of Jas. Becker Cabinetmaker, Inc., who is an expert on varnishes. Read on for a Varnish 101 lesson from Jim!

 

Question: First things first — what is a varnish? 

Answer: Varnishes include a wide variety of ingredients and levels of durability and include interior, exterior, and nautical versions. Most varnishes are brushed on. Some, like Waterlox, are easy to apply and not overly susceptible to dust. Others, like Belens Rock Hard Table Top Finish, give a beautiful, durable and deep (meaning that you look through a thick transparent coating, giving a feeling of depth to the wood surface) finish, but require a dust-free environment and final rubbing-out with pumice at the end of the process. 

 

Question: Is there a difference between a lacquer and a varnish? 

Answer: Lacquers are the finish you most often find on “furniture store” inventory. The finishes are relatively quick to apply and dry quickly as well. The resulting appearance can be thin or “deep” built-up coats and can be, but don’t necessarily need to be, rubbed out at the end of the process. If damaged lacquer finishes are more difficult to repair, especially the catalyzed versions.

Lacquers are sprayed on and come in various degrees of durability with catalyzed lacquers being the most durable (think thin, sprayed epoxy). Some are petroleum-based; others are water-based.

 

Question: Do you use lacquers often and when? 

Answer: I have used catalyzed lacquers most often on veneered pieces. I like the extra protection it affords. It is mostly impervious. 

 

Question: What is shellac and how can it be used?

Answer: Shellac is the non-toxic, purified secretion of the lac beetle. It is dissolved in alcohol and either brushed on, or can be “padded” on with mineral oil in a process known as a “French Polish.”  

Brush applications require a dust-free environment. After building up the depth with multiple applications and sanding in between with 400 grit sandpaper, the final coat of the finish can be rubbed with 0000 steel wool to dull the shine and/or to rub out any dust motes in the surface. Old shellac finishes take some skill to repair if they are beyond waxing.

Shellac can provide beautiful finishes from glossy to the deep slightly dull sheen of French Polish. Its one major drawback is that it dissolves in alcohol, so a spilled drink is a disaster.

Question: Why do you use many different finishes?

Answer: There is no “perfect” furniture finish. If there were, we would all use it and life would be much easier for furniture makers!

In order of durability from “not” to “very,” I identify oils (most often linseed or tung), shellac, varnishes, lacquers, urethane, and catalyzed lacquer finish. As a rule, the less durable the finish, the easier it is to repair; the more durable, the harder it is to repair if damaged.  

Oils, often followed by waxing, give a beautiful dull sheen. They are relatively easy to apply and are not sensitive to dust during the finishing process. I use them most often on seating, or pieces and/or parts that won’t  be spilled upon. Spills result in spots very quickly, however oil finishes are relatively easy to touch up. Often a new coat of oil added and wet-sanded over the “spots” or rings is the solution to the problem.

Question: What is your preferred finish and are there any brands you especially love? 

Answer: I like linseed oil better than tung oil in part because of the smell and partially because I have found a totally non-toxic brand, Tried & True. It’s the only finish I apply with bare hands. Tried & True works well, but requires a 70-degree minimum temperature to dry and is more difficult to apply than the slightly toxic, boiled linseed oil available in hardware stores. 

 

Question: How can you maintain a finish? 

Answer:  Most finishes will wear and dull over time. My preferred method of care involves paste wax (obtained at a hardware store). Apply with a soft rag, let sit until the solvent, most often turpentine, gasses off and then buff with another soft cloth or paper towels.  

Over application of wax can result in an easily smudged film; the extra wax can be removed, but it takes care and or the right solvent. Wax can spot or ring if spills are left for any time on the surface. Most often such rings or spots can be rubbed off  using a little more wax applied with a piece of 0000 steel wool (available at hardware stores) rubbing very gently in the direction of the wood grain. You may have to wax the whole piece to even out the shine on the rest of the piece.

[sharethis]

Leave a Reply

Your email address will not be published. Required fields are marked *