Guerrilla Guide to Spray Finishing
by Christopher Schwarz
The hardest part about learning to spray finishes is becoming convinced that you can learn to spray finishes.
Of all the ways to apply finishes – brush, rag, rubber and spraying – there’s only one method easier than spraying: ragging on oil. Spraying finish is always faster than any other application method – astonishingly so. I can spray two coats of lacquer on a chest of drawers and have the thing assembled in just a few hours (compare to a few days with a hand-applied finish).
Oh and one more thing: In my opinion, spraying produces better results.
Plus, with good spray systems now costing about as much as a half-decent cordless drill, you just ran out of reasons to avoid spraying.
If you’re a professional finisher or refinisher, this story is not for you. Most of the resources I’ve read about finishing are aimed at people in cabinet shops or industry. This article is for the home woodworker who wants to get the speed and quality of a spray finish but doesn’t have money or space for dedicated setup.
I first learned to use a spray gun as a teenager working in a door factory, and I’ve used everything from industrial equipment down to the plastic DIY units. And while I could spend most of this article discussing all the differences among the systems – high-pressure vs. high-volume-low-pressure units (HVLP), bleeder vs. non-bleeder guns – I don’t think that’s as important as the basic techniques involved in spraying. (I do think that most home woodworkers would be better off with an HVLP system, but that’s just an opinion.)
All the systems are more similar than they are different: Air is forced through the finishing material, atomizing it into a fine spray that you control with a spray gun. You control the mix of air with the finishing material, the shape of the cone of finish squirting from the gun, and (of course) when finish is coming out of the gun and when it is not.
These are easy things to learn to control.
The second part of spray finishing that bemuses people is how to actually spray the work. Where do you start and finish? How do you finish interior spaces? What about legs?
I’m going to discuss all of these aspects of spray finishing. But first, let’s talk about what you can and can’t spray.