Flexner on Finishing: Choosing a Spray Gun


Though a good finish can be achieved with other methods, guns are faster.
By Bob Flexner
Pages: 66-68

From the February 2010 issue #181
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As I’ve explained many times in Popular Woodworking, you can achieve a near-perfect finish using a rag or brush: You can apply a wipe-on/wipe-off finish such as oil, wiping varnish or gel varnish; you can sand a brushed finish level and cover the sanding scratches with wiping varnish or gel varnish; or you can sand a brushed finish level and rub it to the sheen you want using fine abrasives.

But spray guns have some important advantages over brushing or wiping. The most obvious is application speed; applying a finish with a spray gun is much faster than
brushing or wiping.

Spray guns also allow you to use fast-drying finishes to build a thickness rapidly with minimal dust nibs and make it possible to apply a finish film that is almost perfectly level (no orange peel) and to “tone” the wood.

Toning is spraying a finish with a little colorant (pigment or dye) added to tweak or adjust the color of the wood – whether stained or not. Toning can also be used to create highlights and other decorative effects.

The downsides of spray guns compared to brushes and rags are greater cost, increased waste because of overspray, and considerably more complexity to keep the tool in good operating condition.

So how do you choose a spray gun if you decide you want to take advantage of its benefits?

It’s actually quite straightforward. First, you decide on your source of air: compressor or turbine. Second, you choose a spray-gun configuration: siphon-feed, gravity-feed or pressure-feed. Third, you decide on quality – that is, how much you’re willing to pay.

And finally you choose a brand. Because competition keeps all manufacturers on the cutting edge of the technology, this is not as complicated as you may think.


From the February 2010 issue #181
Buy this issue now