A Little About Airbrushing
August 14, 2011 | 9:35 pm CDT

Old techniques and tools, such as airbrushes, are still handy for making finish repairs and adjustments.

This sample shows green oxidation on a gold shaded edge.
First step in the repair process is sanding with a fine grit abrasive.
An airbrush is ideal for blending the base color coat and gold color.
Aerosols are good for clearcoats to seal in the colors and protect the finish.
The sample repair is complete after it cures.

In the finishing, refinishing and restoration business, you never know what your next job is going to be. It may involve doing work on furniture from a different era, with old-style finishes.

In this vein, I decided to look back at the 1950s and ’60s when gold and silver bisque finishes were regularly used on bedroom, living and dining room furniture. This trendy finish came in various shades of antique whites, tans and blonds, shaded around the edges with gold or silver coatings. There was other furniture that also used shading colors around the tops and on the drawers and sides.

At that time in my finishing career, I was mainly doing outside repairs and restoring customers’ furniture on-site in their homes, offices and warehouses. It was common with many of the popular bisque finishes that over time they would oxidize (turn green) where the gold or silver shading was sprayed around the furniture’s edges. Many finishing repairs involved removing the green.

In this article, I will discuss how I repaired those finishes, including how I used an airbrush. I found the airbrush to be a very valuable tool not only for bisque finishes, but also for doing all kinds of repairs and restorations. These techniques can have applications even today.

The first photo on the right shows a simulated green area, with oxidation on a gold shaded edge. This occurs from combining composition gold bronzing powders into a nitrocellulose lacquer coating.

When this happened in the “old days,” many customers blamed the furniture manufacturers and, in turn, the manufacturers blamed the customers, claiming that the oxidation was caused by lacquer coming from the “acid” in their hands, scalp and hair.

It was hard to argue with the manufacturers, as the green coloration often showed up where pillows touched the headboard and in areas around drawer handles. However, it also showed up in other places where the hands or head didn’t normally touch the furniture. Some finishers claimed that nitric acid in the nitrocellulose lacquers caused oxidation of the composition metals in the bronzing powders used in the gilded shading.

When a customer called the store where he purchased the furniture and complained about the gold turning green, a serviceman was sent to make a report, but no one would repair this problem in the home. In some cases, furniture stores would pick up the piece and renovate it in their own repair shop or send it out to be refinished. Sometimes they charged the customer and sometimes not.

Repairing the Oxidation

What finishers typically did to remove the green was sand the finish until there was no more of the green showing, which meant removing the finish, and building it back up to the level of the rest of the finish. At that time, there were aerosols we could use, available in many colors, clearcoats, primers and sealers. But the key to making a good repair was also using an airbrush and a small portable compressor.

What I did was develop some colors, using universal colorants and water clear coating, that I could use for blending in the base color coat. I used the base colored toners with an airbrush instead of colored aerosol because the airbrush produced less overspray and fumes. The airbrush also worked well to build up the color coatings fairly level to the surface. But its main job was blending in the shadings of gold and silver. (Note: The airbrush had to be cleaned as soon as the toning and metallic shading was completed.)

I did use water clear aerosols for the final clearcoats to complete the job. As with any finish, the final clearcoats had to be allowed to dry completely.

Tips for Success

Sanding is very important to doing such repairs, and I found that it is better to use finer grit sandpaper and take longer to remove the green than to use coarse sandpaper and leave deep scratches in the primer or the wood. Once the green is removed, I wash the areas with mineral spirits to de-wax the surface around the damage.

Depending on the depth that was sanded, I primed and sealed the area and then force-dried it with a hair dryer. I allowed it to cool and repeated the process until I was close to the level of the surface. The hair dryer speeded up the drying process, which saved a lot of time. But it must be used with extra care, because you can damage the repair if you get too close to the finish.

After that, I matched the color of the finish by comparing it with my base color coats. In many cases, I had to make a little adjustment to get a close match. Once the color was matched or very close to the original, I airbrushed in the shaded gold or silver around the edges. In some cases, I extended the metallic shading out further than the repaired area to get a better blending match and take the customer’s eye away from the repair.

The final step was to apply a couple of water clearcoats from the aerosols and blend the overall coating. Without the airbrush, it was difficult to make the repairs look professional. I found the airbrush to be a valuable and versatile tool that I think every finisher should have.

I expect that as with other style trends, gold and silver bisque finishes will become popular again in some form or another some day. But thanks to the newer gold materials and better selection of coatings that are produced today, they should not turn green — unless you mix the wrong coating with some aged or defective composition bronzing powders. Regardless, I still tout the value of having and using an airbrush, both inside and outside the shop.

Mac Simmons is a freelance writer and 50-year veteran of the furniture finishing, refinishing and restoration trades. He has written articles for woodworking magazines in the U.S., Canada and Europe and just introduced a new finishing e-book on CD for $24.95. For information or orders, write Mac Simmons, Box 121, Massapequa, NY 11758. Other questions may be directed to him via e-mail c/o [email protected]

Have something to say? Share your thoughts with us in the comments below.