Questions: Wenge

by John Calkin

Originally published in American Lutherie #61, 2000

See also,
Questions: African Wenge by Jeffrey R. Elliott

John Calkin of Greenville, Virginia responds to Milan Sabljic’s question regarding wenge and Willy Ware’s questions regarding superglue’s interaction with finishes.

Wenge is hard, yet very brittle. Splinters are a constant threat. There’s also a striking difference in hardness between the wood from different seasons. I recently made a copy of a Gibson L-00 with wenge sides that were sort of quartered and a back that was flatsawn. Keeping the back free of ripples was a nasty task involving a lot of block sanding. It’s almost as bad as softwood in this respect. Wenge is also one of those surprise woods that attack some people. The man who gave me my first piece of wenge said it gave him an intense headache when he resawed it. The exact same board had no affect on me.

Superglue drop fills: At Huss & Dalton we do drop fills on conversion varnish all the time, and they are invisible. In my own shop I’ve found that with lacquer and Crystalac it should be used between coats so that it can be aggressively sanded flat, otherwise the fills are devilishly hard to hide. Fills used on the surface usually leave a witness mark around the perimeter. Even when the feather-out is perfect and the surface looks and feels dead-on after flat sanding, the fill is often visible after buffing. Finish repairs done in superglue look much better than the ding or scratch, but they are seldom perfectly invisible. Awhile back I resurrected a much-abused mahogany parlor guitar of low value. The back was cracked and dented, and I did all the repair work with dozens of puddles of superglue. The back stabilized wonderfully and looked perfectly flat after sanding. After French polishing it looked like a new guitar, but after a couple days every fill telegraphed through the shellac. More wetsanding and polishing followed, but the fills kept coming through. I finally had to tone down the gloss to make the work acceptable. My customer was thrilled, but I wasn’t happy at all. I’ve decided that the smallest amounts of CA glue possible should be used on instruments, and if possible it should be mixed with sanding dust to stabilize it. The stuff is a life saver, but it’s not quite God’s gift to lutherie. ◆