Many years ago, one of the big varnish manufacturers had a regular advertisement showing a cowering boat owner eyeing a brightwork project with a feigned expression of terror, and saying “Vvvvvvvvarnish?” Such fear is a common sentiment among would-be and occasional varnishers, and for good reason: Varnish provides excellent protection while showing the beauty of the wood, but it takes a consistent commitment of time and skill each year to maintain it. And achieving a good bright (aka varnished) finish in the first place requires careful surface preparation and application.
There are myriad pitfalls that can compromise the job along the way, and a lack of maintenance during the season can ruin a fine job. Paint, frankly, is a better option for those who lack the time or inclination to maintain varnish. Indeed, vast expanses of paint (cabinsides, for example) accented by bright trim will look much better than poorly maintained varnish. Varnish, however, is not only rewarding aesthetically; because it’s transparent, it also can reveal potential areas of rot that show up early as dark, discolored spots before they become a serious problem.
Some great books and articles have been written on the topic of varnishing (see Further Reading at the end of this article). For those seeking a more succinct lesson than those tomes provide, all major varnish brands include on their labels a concise set of instructions. I’d wager that that’s where most of us take our initial varnishing advice. Yet, due to the space constraints of the can, these instructions are typically printed in a barely legible type size, and they leave some room for interpretation—especially for the first-time varnisher.
So, the goal of this article is to interpret the varnish can—to give a bit more depth to those instructions, without writing a book. A can might say to remove all dust. We’ll look at how we do that, and the other basics of varnishing, leaving aside tangential concepts such as two-pack systems, spray application, wood staining, and stripping of old finishes.
Simon Adams
A block of foam insulation can be shaped to a contoured surface to create a custom sanding block.
Preparing and Sealing Bare Wood
All labels will tell you the wood must be clean and dry before varnishing. But there are a few other considerations, too. Painters and varnishers have an old adage: “It’s 90 percent prep work.” Divots and unevenness in the surface will telegraph into the finish coat, so be sure to get your bare-wood surface as smooth and scratch-free as you’d like it to be when finished. If you can live with raised and uneven grain, then a thorough sanding is all it takes. But if you’d like a mirror-smooth finish, now is the time to begin working toward that.