Our Varnish Finish
We finish our table, desk, and buffet tops with polyurethane varnish to build an impervious layer of protection, unless an oil finish is reqested. Liquids can dry on the surface without penetrating. Polyurethane varnish is superior to the lacquers commonly used for furniture finishes in these ways:
- Its impermeability is greater.
- Its resistance to "clouding" due to heat is greater.
- It is tougher and more flexible, not brittle, so that the coating will follow a dent without chipping and not show a broken-glass-edge along a scratch.
- It is visually and tactilely less obtrusive.
- Its sheen and depth are comparable to, and almost indistinguishable from, those of our hand-rubbed oil finish.
But polyurethane varnish is more difficult to apply than lacquer, because it is slow to dry and has a higher content of solids in the solvent. While drying, it can be contaminated by settling dust. It is tricky to spray — we brush it. It takes days to put on a varnish finish because each coat must dry overnight or longer, whereas a lacquer finish can be completed in hours.
Because of the difficulties of application, varnish finishes are known for their thick and thin places, runs, laps, lines, and roughness from dust. We have learned to create a varnish finish without these defects with a surface that equals or rivals the best sprayed lacquer finish in its flawless, even, smooth surface. "We have learned." Three words, many years. The breakthrough was the VOC scrubber we built to remove solvents from the air of the finishing rooms. This allows us to maintain temperature at 75 degrees and relative humidity at 45–50%. We filter and re-circulate our conditioned air.
The application of varnish is extremely sensitive to temperature and humidity. At the optimums we maintain, it dries quickly, but also flows out smooth. If varnish dries too quickly (higher temperature), laps and lines do not flow out. If it dries too slowly (lower temperature or higher humidity), it drips on the edges and captures dust. And if it dries too slowly, you must wait two days before sanding and recoating for it will "gum up" the sandpaper and cause other mayhem. A surprising additional benefit to the scrubber was its dust filtering efficiency. We have built a low tech clean room, scrubbed of vapors and dust.
Cleanliness is imperative in every way. We vacuum. We blow the dust from clothes and tools before entering the room. All mixing and pouring of the material is meticulous to avoid contamination.
Maintaining Our Varnish Finish (or our hand-rubbed oil finish)
Whatever product and schedule for maintenance that you use on your other furniture are almost certainly fine to use on our furniture. If in doubt, please ask us.
If the surface is soiled in some way, wipe it with a damp, or nearly wet, cloth. If the soiling is particularly stuck or built up, use a little soap or detergent. Rinse with a damp, or nearly wet, cloth. Dry thoroughly.
Polish with a lemon oil product. Good ones are available at grocery or hardware stores. We keep a rag with the oil. Add oil to the furniture or to the rag and rub until there is an even and complete coating. Rub and buff with a dry cloth to remove any excess.