Q:

Occasionally, I find small knots and blemishes in the wood I use to build furniture. What’s the best repair for them?

Jay Riley, New Orleans, LA

A:

The best repair is an invisible one. This means that any patch should match both the color and the grain of the surrounding board. The best source is a cutoff or scrap from the same board. Select a flatsawn scrap that has a 2-in. to 3-in. section clear of any growth rings. Plane it down so it’s 1/8 in. to 3/16 in. thick. If you don’t have a suitable piece, make it at the bandsaw by cutting a flatsawn board to minimize the number of growth rings visible. Cut a diamond-shaped or triangular patch, but not a rectangle. Cuts that run diagonally across the grain are far less visible than those running perpendicular to it.

Not all defects are natural. Buckshot and bullets can lie hidden beneath the surface of even the most beautiful board.

No grain allowed. The best patches are made from flatsawn stock with no visible grain. Resaw between grain lines if possible to minimize them.

 

Shape of patch is key. Diamond-shaped and triangular patches disappear better than square ones, because cuts that run diagonally across the grain are far less visible.

Plane or sand the edges of the patch smooth and bevel them slightly for a tighter fit. Then place the patch over the damaged area and lightly trace around it with a marking knife.

Scribe around the patch. Use a marking knife to trace the patch’s outline.

 

Cut an accurate mortise. The precise mark allows you to cut an accurate mortise, which helps hide the patch. After routing away the waste and cleaning the edges with a chisel, glue the patch into the mortise.

 

Artistic license. Grain lines, drawn with a brown pencil, make the patch disappear.

Rout away the waste and clean up the edges and corners with a sharp chisel. Glue and clamp the patch in place. After sanding the patch flush to the surrounding wood, use a brown pencil to lightly draw in grain lines that connect to the surrounding wood.

Fine Woodworking Recommended Products

Waterlox Original

Versatile wiping varnish is easy to apply and great for both satin and gloss finishes.

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AnchorSeal Log and Lumber End-Grain Sealer

Good for both sealing the end grain of freshly cut logs and boards, this wax prevents end-grain checking and saves material

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Bahco 6-Inch Card Scraper

The size and thickness are what matter here. A consistent performer, this Bahco scraper is found in many shops we visit.

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