Builders' Forum Archives
Re: varnishing dilemna
Posted by terry on Jan 28, 2005
A few things I learned and somehow managed not to forget from my job assisting a sign-painter as a youth. He put gold leaf lettering on yacht transoms and I covered the leaf with a few coats of varnish. We often worked in the typically cool, damp weather of a New Jersey early spring.
We would always add some lacquer thinner to varnish to accelerate drying and minimize runs; more (maybe 10% or more) in cool or very humid weather, less (maybe 5%) in other weather. Also, and I presume you already know this, we'd work very fast and apply the varnish thin, as in THIN, as in REAL THIN. Runs are a pretty good indicator that the varnish is being laid on too thick for the weather conditions and/or verticality of the surface.
Also, I varnish with a brush. On vertical surfaces that are most prone to runs and sags, I lay on a section (maybe two feet), then scrub the varnish with fast swirling motions, actually working up a bit of a lather. This helps stiffen the varnish to further minimize runs. I then tip off quickly with the grain and leave the work alone to dry in peace. Any small runs that do appear I carefully scrape off the next day.
A word on lacquer thinner: health-wise, it's thought to be a greater hazard than most other organic solvents normally found in paints, not to mention its inherent flamability. Close off the room, wear your respirator with a fresh organic vapor cartridge (i.e., please don't wait until you smell something to change the cartridge), and vent the room outside with a small fan. If you can get the room near 70 degrees, you can use less thinner . Othersise add more lacquer thinner.
I've had good luck varnishing indoors and out in a wide variety of temps and humidity. Can't see any reason why you can't be just as fortunate.
In Response to: Re: varnishing dilemna by Gert Walter on Jan 28, 2005