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20 Finishing Tips

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20 Finishing Tips

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Make dewaxed shellac

Take the wax out of shellac and you have a great sealer that’s compatible with most other finishes. It’s best to get this “dewaxed” shellac as dry flakes that you mix with denatured alcohol. Usually you have to order the flakes through the mail. But in a pinch, you can decant (draw off one layer of liquid from another) dewaxed shellac from the canned shellac you’ll find at the hardware store.

Bring a clean can or lidded jar with you to the store. With the okay of a salesperson, carefully carry a can of shellac to the counter and open it. If the liquid looks creamy, like cappuccino, put the can back and try another one. A good candidate for decanting will contain a clear, deep amber-colored liquid with a creamy-colored layer of residue at the bottom. This indicates that the wax has settled out. You can decant between two and three cups of dewaxed shellac from a quart of liquid shellac. After decanting, pay for the shellac and ask the clerk to dispose of the can with the waxy residue.

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Decant dewaxed shellac from a can at the hardware store. Find a can in which the wax has settled to the bottom and pour off the pure shellac from the top.


Thin the decanted shellac with an equal amount of denatured alcohol for use as a sealer.



Eliminate drip shadows

When finishing a large flat surface, the temptation is to finish the top first. Inevitably, some varnish runs over the edge and soaks into the end grain. Even after you finish the edge, the soakedin drips remain as dark shadows. No amount of re-coating takes care of it and you’re faced with having to strip, sand and refinish.

Fortunately, the problem is easily avoided. Coat the end grain with a thinned coat of varnish before tackling the top. A mixture of two parts varnish to one part mineral spirits works well. The drips won’t be able to soak in and leave their shadow.



Use two brushes to control drips

A big brush that holds a lot of finish is great for covering a large flat surface. But that same big brush often leaves too much finish on its thin front edge. The remedy: use two brushes. First, using the big brush, quickly cover the front edge and an adjacent section of the top with finish. Tip off this swath of finish on the top with the big brush. Then switch to a second smaller brush and smooth out the coat on the edge, removing any sags and drips as you go. Once the edge is finished, switch back to the big brush, feather in where you left off and finish the top.

Drips and sags on the front edge of a board are hard to clean up with a big brush because it leaves a heavy coat that’s likely to sag.


Use a second brush—small, disposable foam ones work great—to get rid of drips and sags on edges. The secret is to keep this second brush fairly dry—only dampened with mineral spirits—so it can wick up excess finish. Hold this brush at an angle so it cradles the bottom lip of the edge and make one long end-to-end stroke. If you need to make a second pass, put on a plastic glove and squeeze out the brush.



Test finishes on hidden areas

Here’s one of the best (and most ignored) tips for getting a great finish: test the stain colors and topcoats you’re considering for your masterpiece on its hidden areas. If your piece has no unseen surfaces, use offcuts from the project or leftover scraps of the same wood.

Prepare the areas for your hidden tests as diligently as the parts that show. Record your finishing procedures for each sample. Be sure to topcoat stains and dyes—they usually look totally different under a finish. Aerosol cans of shellac or lacquer work great for this. Be sure to look at your samples under the kind of light the piece will live in— finishes look different under natural or incandescent light than they do under fluorescent shop lights.



Make surface checks disappear

Don’t let small surface checks keep you from using an otherwise good board. Got a minute? You can make those checks disappear.

Squeeze cyanoacrylate (CA) glue into the crack. CA glue works better than yellow glue because it dries very quickly. Any brand of gap-filling CA glue with a 5- to 15-second open time will work. Use a tip with a pin-sized hole (you can get replacement tips for 50 cents at hobby stores).

Immediately sand the area, mixing sanding dust with the glue and packing it in the cavity. Keep sanding until the crack is filled and the excess glue is removed. You may need to repeat the process. Under a finish, the sanding dust/glue mixture is almost invisible.




This story originally appeared in American Woodworker January 2007, issue #126.

January 2007, issue #126

Purchase this back issue.

Purchase the complete version of this woodworking technique story from AWBookstore.com.