My recent post about water based varnish generated some questions about water based lacquer, so I’ll address those today.
Just so you know, anywhere from three to four times a day my phone rings and a customer asks, “Does [this product] create a lacquer type finish?”
When the word “lacquer” enters the conversation a deep, wide rabbit hole opens…
And we can quickly descend into the world of defining the chemistry, function and purpose of what a “lacquer” really is.
Some conversations are quick; others seem to take forever to conclude. So, I’ll do my best to keep things simple and avoid the hair-splitting minutia.
Here are a few important points that will help you determine if the term “lacquer finish” is appropriate for your own world of wood finishing.
I’ve always found it best to categorize wood finishes by their function and performance. Artisan and industry standards over the long-term have helped to define the products that we use.
So, by that measure, as a wood finisher, why would you consider using a lacquer over another type of finish? Here are several answers from my customers:
-It’s user friendly from a repair and refinishing perspective, i.e. the coats/layers “burn in” to each other.
-It dries fast.
-It dries clear – or nearly clear when applied in the right ambient conditions.
-It offers protection/durability on a “utility” basis; it is a good all-purpose interior finish.
Ready for the deeper dive? Here we go…
The Merriam-Webster dictionary defines lacquer as…
1a: a spirit varnish (such as shellac)
1b: any of various durable natural varnishes especially: a varnish obtained from an Asian sumac (Rhus verniciflua)
— called also Japanese lacquer
2: any of various clear or colored synthetic organic coatings that typically dry to form a film by evaporation of the solvent especially: a solution of a cellulose derivative (such as nitrocellulose)
OK, there are two keywords here that gets the dust flying – varnish and shellac.
While I learned years ago never to argue with lexicographers, I do find definitions of words that veer outside of specific industrial terminology often end in bar fights.
So, with this in mind, let’s respectfully toss out the words “varnish” and “shellac,” and instead focus on nitrocellulose lacquer to help us define what has also become available in water based formats in the late 20th century going forward.
What is a nitrocellulose lacquer? A “nitro lacquer” is made from the fibers of cotton and cellulosic materials, which are reacted with nitric acid to create a resin.
This resin, diluted with alcohols and other additives, are used to make a low-solids, highly reactive coating that found a wide array of adaptations in the early 20th century for use in furniture and automotive finishing due to their ease of use, fast dry-time and reasonable degree of durability.
The downside to nitro lacquers is the inherent danger when using them – nitrocellulose lacquers are highly combustible and require great care in their use and handling.
Skipping forward, in the early 1980’s a new array of water based acrylic and urethane resins began to make their way into wood floor coating formulas.
Because of their good durability and relative ease of use, the term “lacquer” was used when marketing these early finishes without focusing on the actual function and performance.
Thus, when I began formulating the first generation of Oxford water based lacquers, I was determined to categorize the finishes I created by how they performed compared to their solvent-based counterparts.
So, when we look at a nitro lacquer as a cross comparison, what do we see?
As I mentioned above, the very first performance value that makes solvent based lacquers so endearing to the end-user is its 100% burn-in capabilities.
“Burn-in” is the function in which the next coat of lacquer melts, or “burns” into the previous coat. Due to the very high solvent content used to make a nitro lacquer, these solvents — ketones, xylene, naphtha and other “hot” solvents — reactivate and melt the dry/cured cellulose film that they are being applied to.
This reaction allows for the cellulose resin to rewet and blend together – creating a unified, single film formation. With each coat melting into the next, the final, cured coating is easy to polish and repair.
Now we find ourselves with water based acrylic coatings being sold as lacquer substitutes. Some brands available today fall short of the performance criteria to be deemed a “lacquer” the way we’re defining it – others live up to the definition quite well.
For example, the Emtech® EM6000 Production Lacquer and the refined EM7000HBL provide physical characteristics and functionality that behave just like a nitrocellulose lacquer.
These characteristics are:
-100% burn into its previously applied coat.
-fast recoat time.
-easy repair and polishing response.
-good utility-grade durability.
Are these two formulas made with cellulose fiber? No, they are made with fine particle acrylic polymers and water-soluble propylene series solvents.
So, in the literal definition of “lacquer” they do not qualify. However, in their performance and function analysis they meet all the criteria of a high-quality production lacquer finish.
As you can see, this conversation can go on at length. In the end, it is up to the coating manufacturer to properly define and categorize the name and purpose of the finish they are taking to market.
By not doing this, we see on-going confusion in the wood finishing community. I hope I cleared some of it up for you today.
What water based lacquers, if any, do you use today, and what do you like/dislike about them? Please share your thoughts or read what others are saying below in the comments section.
As always, stay safe and stay creative.
-Jeff Weiss –