the Lacquer
Finishing Secrets No. 11 - LACQUER
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We could make it easy by just picking up a can of Deft at the Woodcraft store. That would work, but there are some differences in lacquers, and a finish that requires some thought and preparation deserves more than that. It well may be that we still end up using the Deft, but we should be using it for a reason.
About The Lacquers
All commercial lacquers contain “solids” and a lot of thinner. The solids are what is left behind as the finish after the thinners have evaporated. It is these solids that make the differences in lacquers. Not all lacquers are created equal, and lacking any other knowledge, price is a good indicator of quality, and the weight of the can the amount of “solids” it contains.
Commercial Cellulose lacquers (Park, etc.)
These are a common Nitro-Cellulose lacquer. I don't recommend them for our use because their surface film will turn yellow in color and become brittle with age, and that age is within the range of 5 to 10 years. These lacquers will turn a very dark brown color with age while they are still in an unopened can, Expect to pay about $15.00 per gallon for these products.
Deft, Watco, and Minwax
Deft has been around forever. The other products are new within the past couple years (ca. 2008). They appear to be the same as Deft, but time will tell whether they age the same. I will refer to Deft in this discussion because that is the one that I am familiar with. I will leave it to the reader to determine whether the others are the same or better.
One difference I have noticed is the color of the product in the can. Deft was once a clear "water-white" color when it was fresh. That changed in the mid-1980's when it took on a decidedly amber color. Over the years it has changed colors to a greenish-blue, and the current Deft is a definite yellow color. The Watco lacquer is water-white, and I have yet to open a can of the Minwax lacquer.
Deft is also a also a Nitro-Cellulose Lacquer. For a price of $32.00 a gallon, it offers the same solids content as the less expensive lacquers. However, it has an advantage over the common nitro-cellulose lacquers because it has been modified to remain more flexible, and not yellow as fast with age.
These are called “brushing lacquers” because they come already thinned with “retarding” thinners that take longer to evaporate. This allows the surface to "level" into a smooth film before before sufficient solvents have evaporated to fix the surface film. Hopefully this period has allowed the brush marks to disappear, or at least become less visible. There is always a downside to using these lacquers because the slower drying also allows more time for runs to develop on the surface.
Deft, like any other brushing-lacquer, can be used in a spray gun, and usually without using any thinner. Its slower drying rate can useful, but will also contribute to “runs” and “sags” in the surface film if we are not careful. Contrary to what is printed on the can, or in their literature, Deft can be thinned with any commercial lacquer thinner.
Out of habit more than any logical reason, I use Deft as a general wood sealer and brush-on finish. It is easy to use, brushable, and readily available. But, I will never use it for the “museum quality” lacquer finish.
I am now working on my first gallon of the Watco lacquer, and so far I can't see any difference.
CAB-Acrylic Lacquer
The CAB is short for Cellulose Acetate Butyrate. To some degree, all lacquers become brittle with exposure to sunlight, but the CAB-Acrylics will stay more flexible than anything else that I have used. At a price that is only slightly higher than Deft ($36.00 a gallon), the lacquer by Sherwin-Williams is “water white” in the can, and it will not turn yellow in our lifetime. There are similar products available from Kelly-Moore and other sources, but some of them can already be an amber color when the can is opened.
I thin it to no more than 50/50 with a commercial thinner for application with 30 PSI at the spray gun. Any product labeled “Lacquer Thinner” can be used.
Ditzler (PPG) Automotive Lacquer
This is the best of the several brands that I have used over the years. It will not turn yellow with age, and its film is flexible enough that it will not show cracks on any but the most flexible of our wood turnings.
We will have to go to the automotive paint supplier to purchase this product. Be prepared for a shock when you see the price because it retailed at $36.00 a quart the last time I bought it. Yes, that is “quart”! This lacquer is sold for use in high-pressure spray equipment, and as such has an extremely high solids content. I thin it to a 3-to-1 or 4-to-1 thinner-to-lacquer ratio for application with my siphon gun at 30 PSI. At that thinning rate, it is actually cheaper than Deft.
Waterborne Lacquers
I will not include the waterborne products that are called and sold as “lacquer”. I have always stayed away from them because they didn't melt into the previous coat like a solvent lacquer, adhesion between coats was always a problem, their film had a cloudy bluish tint, and they weren’t crystal clear. There are some new products coming into the market that will solve these problems, but they aren't generally available at this time, and I have no experience with them. From what I have heard, they behave like a lacquer, and the turned wood I have seen with these finishes looked like a lacquer. I will add them to this list after I have used some of them.
Catalyzed Lacquers
While they are excellent products that will yield a durable gloss finish, they are for “professional use only” because they require ventilation and personnel respiration equipment that is beyond the scope of the normal woodturning shop/studio.
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This page was last updated: December 10, 2011
