Nitrocellulose lacquer is a wood finish applied to furniture and other surfaces to protect and beautify them, but it’s not without its dangers. In this article, we’ll talk about how to protect yourself if you work with nitrocellulose lacquer, what you can do to stay safe, and about suggestions for better handling and preparing paint batches for use.
You’ve probably noticed that many vintage furniture pieces are beautifully worn. The faded, crackled finish of an antique chest of drawers or chair legs tells a story – of long days in the sun, perhaps, or generations of hands touching them.
Modern paints don’t produce the same effect, and many artists and craftspeople want to create that look themselves. That’s why nitrocellulose lacquer has enjoyed a renaissance in the last decade. It’s an extremely durable finish that creates a look of weathered history without needing to spend decades aging the piece. But working with nitro finishes is not without its risks.
What is Nitrocellulose Lacquer?
Lacquer is a varnish-like finish typically made with resin (usually shellac), alcohol, and pigment. Cellulose lacquer is made with resin, alcohol, and cellulose (an organic material produced by plants and some animals). In nitrocellulose lacquer, the cellulose replaces a portion of the natural resinous sap produced by trees.
Nitro finishes are made in a so-called semi-solid method. In this process, paint particles settle on the bottom of a tank while liquid forms on top. The top layer is skimmed off, hardened, and finished, while the bottom layer is left in the tank to continue settling.
The problem is that paint particles contain wood resins and other ingredients. So, as you skim off the top of the paint tank, you’re also taking in some of those resin particles – along with the varnish resins that give lacquer its durable quality.
Those particles are likely to clog up gauges and make breathing difficult in tanks, which is why many workplaces require face masks when working with nitro finishes. Nitro finishes are made in several types. The type used for furniture paints, called cellulose nitrate (called shellac nitro lacquer), is generally less durable but less toxic. Benzene nitro (also called cellulose) lacquers are more durable and toxic.
History of Nitrocellulose Lacquer
While employed by the DuPont Chemical Company in 1921, Edmund Flaherty created the first nitrocellulose lacquer. The Ford Motor Company immediately acquired the rights to it. When combined with pigments, nitrocellulose produced an outstanding, quick-drying paint that greatly accelerated Ford’s automobile manufacturing.
Ways to Protect Yourself While Painting with Nitro Lacquer?
It’s important to be mindful and take precautions if you need to work with a nitro finish. Because nitro lacquer is an oil-based paint, it’s toxic and flammable. It would be best if you took special precautions when working with it.
Ventilation is especially important when painting wood with nitro paint. Setting up proper ventilation if you work in a confined space is important. You must build a paint booth if you don’t have adequate ventilation in your workshop. Ensure open windows are located at least 10 feet from doors or other openings.
Wear odor-resistant gloves and a mask to protect your lungs whenever you paint. You should also wear eye protection, even if you don’t think you’ll splash anything in your direction. Any paint that gets into your eyes will cause serious irritation.
After you’re done painting a piece, make sure you clean up immediately. Paint that hardens in a pan can be difficult or impossible to remove. Make sure brush powder and scraps get thrown away in closed containers, not in open trash cans.
One of the most effective methods of degradation of nitro finishes is sunlight. Work outside to set up and paint furniture and other items. Covering the item with a tarp or sheets may allow you to work without protective gear if necessary but remember to set up proper ventilation still.
How to Test a Nitro Finish?
You might need to test a nitro finish if you consider repainting a furniture piece or refinishing a door with a pattern.
Scratch test
The easiest way to test a nitro finish is by scratching it. If the paint lifts off with little resistance and shows the wood or metal underneath, it’s time to repair the damage before painting the piece.
Smell test
Another way to test a finish is to smell the piece. Wood coated with nitro lacquer has a distinct odor that differs from other paint types. If you can smell the paint, it’s probably cellulose nitro paint rather than resinous nitro paint, so caution is needed if you plan to repaint the piece. Resinous paints have removed the solvents, making them less flammable and less toxic.
How Long Does a Nitro Finish Last?
Once painted and properly maintained, a nitro finish can last decades, if not centuries. Given its durability and protective properties, many woodworkers, carpenters, and artisans choose nitro paint for nearly every project they can.
Once varnished, a nitro finish is highly water-resistant and can withstand moisture from humidity and occasional rain. Additionally, it resists food and beverage stains.
How to Prepare Wood for a Nitro Finish?
You can’t just paint any wood with nitro paint. The wood needs to be prepared specifically, or it will crack and split when the paint dries. For most projects, you’ll need to apply a primer before the finish paint. The primer prepares the wood by sealing it and creating a smooth surface for the finish to glide on.
How Can You Tell When a Nitro Finish Is Ready to Be Rubbed Out?
It’s important to rub out the finish as soon as possible after painting. Finishes tend to harden with time, making buffing much more difficult. If you wait too long, you may even damage the wood underneath.
When you’re ready to rub out your paint job, use a compound made specifically for polishing lacquer. Do not use car wax or furniture polish on a wood lacquer finish!
What Is Nitrocellulose Lacquer Made Of?
Cotton is used to create nitrocellulose lacquer by being treated with sulfuric and nitric acid, which results in an acidic pulp that can then be filtered to create a watery resin. The final lacquer is created by mixing the resultant resin with a combination of quick-drying solvents.
What Materials are Better?
Well, there are acrylic, water-based, and oil-based versions of lacquers. Oil-based are, of course, less water-friendly. Acrylics are generally more durable and last longer than water-based paints. Water-based paints are better when working in a wet environment like a shower or a pool.
Water-based paints are also much safer to use in your home workshop. They’re much easier to clean up, less toxic, and less smelly. Of course, the paint finish won’t be as durable as oil-based paint, but it will still have a decent shelf life.
Oil-based paints have a longer shelf life but are more flammable and harder to eliminate. They also tend to be more reflective, creating a mirror finish that some woodworkers don’t like.
It’s up to you which one you choose but remember: no paint is 100 percent eco-friendly, so you should carefully weigh your options.
Alternatives to Nitrocellulose Lacquer
As you can imagine, the chemicals present in nitrocellulose lacquer are difficult to tolerate, even under the best conditions. If the toxicity of lacquer bothers you, or if you’re concerned about how to protect your health and the preservation of your wood project, consider these alternatives:
Use varnish with pre-thinned spirits instead of alcohol. This method gives you some wet-dry coverage benefits but less toxicity.
Use oil-based paint combined with linseed or safflower oil. The drying oils in the paints will give you a durable finish while providing water resistance.
Stain and seal with shellac (alcohol-based). Shellac is water-resistant and takes stains very well. Note that shellac isn’t as durable as lacquer, so consider rubbing it with oil-based wax after sealing it with shellac.
Top 4 Tips for Safer Nitrocellulose Lacquer Painting
Whatever finish you choose, here are some tips to keep in mind for safer painting and better results:
- Use a spray gun if you can; it’s easier to get a wet coat, which dries more quickly and helps get the right thickness.
- Make sure you use enough paint for a full wet coat. Don’t skimp-you may need three or four coats to get the coverage you need.
- Leave paint or finish to cure for at least 24 hours before you move furniture or walk on it.
- Protect yourself and your breathing by wearing appropriate masks and ventilation equipment.
Final Words
Now you know the benefits, techniques, alternatives, and tips for working with nitrocellulose lacquer. With this knowledge, you’re well on your way to selecting and using the finish that best suits your woodworking project and personal skill level. So, get ready to start or continue painting and sealing your wood masterpiece with lacquer-it’s a rewarding and lasting finish that will provide great protection!
What kind of lacquer finish do you prefer? Let us know in the comments section below.
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