One of the most common comments we get is how smooth our finish is. While that is a great compliment there is more to a finish than meets the eye, or hand, in this case. In fact, it seems the importance of the protective finish often gets overlooked. After all, if you are going to buy furniture to last for generations why wouldn’t you expect the same from the finish?
All table manufacturers like to describe the features of their tables, quality of construction, and the use of solid wood. I know we are guilty of all three. The finish is so often overlooked that I could not even find it mentioned on other manufacturer’s websites. So in this month’s blog, I thought I would break down the common finishes used in our industry and the pros and cons of each one. I have even included a chart at the end to show which manufacturer uses which finish in hope to provide more information for your decision-making process.
There are a few families of finishes available for furniture but I will discuss the three primarily used in our industry; Lacquer, Conversion Varnish, and Polyurethane.
While the term gets thrown around loosely in the woodworking industry, traditional lacquer specifically refers to a finish that consists of a pre-catalyzed, nitrocellulose finish that has 12 to 18 percent solids per volume and is air cured. Being pre-catalyzed, there is no need for the mixing of hardeners, thus making lacquer a single component finish. This makes it the easiest finish to prepare and spray. Because of the quick drying time, due to evaporation, it becomes dust free in a matter of minutes not requiring furniture manufacturers to have a spray booth. Due to its low solid content, lacquers often have to be reapplied many times for proper build and solid film density. Lacquer is also very rigid and does not allow for wood movement, which is unavoidable in solid wood furniture, and will show white stress crack in joinery over time. Part of lacquer’s popularity is also due to its’ cost-effectiveness, about $35 a gallon. Lacquer is a great finish for decorations, display boxes and even little-used pieces of furniture but just does not hold up well in everyday furniture use like a table will get.
CV Is a two component, post catalyst, chemically cured finish. This particular finish requires the mixing of a catalyst with the varnish itself. This is a delicate process as the mixture must have the correct ratio of the two chemicals in order to harden properly. However, with its higher solid content of about 35 percent by volume after the catalyst is added and a dried film density of twice that of traditional lacquer. CV takes fewer coats for a complete build and satisfactory film density. Because of its ability to cure chemically, dry time is drastically shorter than that of standard varnish but still longer than lacquer. Like lacquer CV is also rigid and can show white stress cracks at joinery overtime. The cost of CV is double that of traditional lacquer, $60-$70 per gallon.
Today’s 2K polyurethanes have few things in common with their one part predecessors. Two-part polyurethanes are pure polyurethanes, meaning both components add solids, unlike catalyzed finishes that use an acid as a catalyst thus lowering the overall solids content. Compared to CV, the most durable of the catalyzed finishes, 2K polyurethane has many advantages. According to the AWI (Architectural Woodwork Institute), it is more wear, heat, solvent, moisture, and stain resistant. That explains why it is the choice for wooden stair manufacturers, wood floor refinishing contractors and even pinball machine manufacturers. In fact, the finish we spray is the only wood finish certified by the AWI for laboratory casework due to its chemical & wear resistance. 2K polyurethane is very popular in Europe, in fact, catalyzed finishes such as CV have been almost totally replaced by two-part polyurethane. The cost of 2K polyurethane is triple the cost of traditional lacquer, at $90 per gallon.
PROS & CONS
|Lacquer||• Easy to apply
|• Low solids content about 15%
• Limited scratch and mar resistance
|Conversion Varnish||• Great scratch and mark resistance
• High solids content about 35%
• Long pot life
|• Most difficult to apply
• Most contain formaldehyde
|2K Polyurethane||• Superior scratch and mar resistance
• Stays flexible• Chemical Resistant
• Highest solids content about 50%
•Contains no formaldehyde
• Short pot life
As you can see not all wood finishes are created equal. That is why I encourage anyone looking to buy any piece of furniture, whether a gaming table or not, to inquire about the finish. I have done some research and inquired with seven of the more known table manufactures as to what finish they use. Again no easy task since it was difficult to find anyone who mentioned their finish on their website.
WHO USES WHAT
|Uniquely Geek||2K Polyurethane|
|Game On||Conversion Varnish|
|Bandpass||Penetrating oil with a hardner|
|Carolina Gaming Tables||Lacquer|
This is not meant to be a knock on any of the finishes because all of them have valid uses in certain situations. I just feel that if you are going to build a piece of furniture that you expect to be heavily used, and build to last for generations, the finish needs to be up to the task.
Please feel free to post any comments or questions.