Applying clear finishes with aerosol cans is quick, easy and, considering the wide range of finish options available, surprisingly versatile. Granted, elegant spray rigs may be more trendy, but “rattle cans” offer a much thriftier path to great results.
Almost every common clear finish is available in aerosols, including shellac, lacquer, oil-based polyurethane and water-based polyurethane. In fact, you can also buy tinted clear coats to add just a bit more color or correct a less than ideal stain job.
Using spray cans is completely intuitive: simply aim and pull the trigger. There’s no mixing needed and no cleanup afterwards, save to clear the tip. Do that by turning the can upside down and spraying until only air comes out. Admittedly, that small button can get tiresome to your finger. A spray can trigger, available where aerosols are sold, is a worthwhile purchase, adding a more comfortable gun-type handle that won’t cause finger cramps.
Curb Your Enthusiasm
On flat surfaces, spray even coats by constantly moving the can in a straight line and overlapping each pass about half the width of the spray fan. Stop when the wood is just wet, and before wet turns into sags or runs. To get an even coat on small round objects, like knobs and finials, mount them on a threaded rod or dowel. Spray while spinning them at slow speed in a hand drill or on a lathe. Drape the lathe bed with plastic sheeting to protect it from overspray.
As handy as they are, aerosols do have one Achilles’ heel; the finish inside, while fast-drying, is highly diluted. That implies two things: you’ll need more coats, which requires patience, and it’s harder to make the more absorbent end grain fill up as quickly as the flat grain areas. You’re on your own developing patience, but here’s a trick to deal with the end grain problem.
Seal and Wipe First
Before using the aerosol, liberally flood the raw wood with Zinsser SealCoat™ and wipe it off while it’s still wet. Let it dry and scuff lightly with 400-grit paper. No SealCoat? You can do the same trick with whatever finish is in your aerosol can: spray way too wet, then pack the end grain with the excess finish while wiping it off the rest of the surface. Either way, one wiped coat will save you time and get you to a much smoother surface faster.