Q. I sprayed some of my recent oil paintings with damar spray varnish, and I was surprised when the paintings seemed to be covered by white spots after the varnish dried. What happened? Am I doing something wrong?
A. Without having a firsthand look at the painting, it seems likely that one of three things has happened. The can of varnish may have been losing pressure as you were spraying, in which case a sprayer begins to spit small globs of varnish. Its also possible that you were holding the nozzle a little too far away from the surface of the painting, in which case the sprayed droplets begin to coalesce and dry before they hit the surface of the painting. The result in both cases would be white spots like those you describe. A third possibility for what went wrong is that you may have held the spray can too close to the painting. This might cause small bubbles in the varnish layer, which would also appear as white spots. When spraying on varnish in the future, be sure to use a fresh can of varnish and hold it the proper distance from the paintings surfacegenerally 8-12 inches. As for removing the spots from the painting on which theyve already appeared, it may be possible if the varnish hasnt cured for too long a time.
To give this a try, dip a soft cotton cloth folded into a small pad in an appropriate solvent for your varnish. Then squeeze the cloth out and use it to gently wipe the surface of the painting. Be careful to remove only the surface of the varnishif you penetrate the varnish layer you may remove some of the painting. Keep an eye on the cloth; if any color appears, youve gone too far.