4. LUMBER DEFECTS TO AVOID
Since I do most of my woodworking with antique hand tools, I like my boards to be as easy to work as possible. Wood defects can be even tougher to work with for a hand tool woodworker like me. Some wood defects can be resolved with saws, handplanes, and even epoxy. But if I’m paying for wood I like to find boards that require as little work as possible. So look out for some of these problems:
Knots can cause problems for hand tool woodworkers, especially when passing your handplane over the top. And knots like to fall out over time. Yes, you can mix epoxy and sawdust to solidify the knot, but most of the time I avoid them all together. But you may like the look of them in a rustic piece of furniture. Just be aware.
SAPWOOD & INSECT HOLES
Some people like the rustic look of sapwood & insect holes. But I don’t. I avoid it, or cut around it. In the photo below you’ll see two boards glued together. The reddish wood is the heart wood. It would be on the inside of the tree. It was dead long before the tree was cut down, so the insects didn’t eat it. The sap would is the white wood with worm insect holes. Insects continue to eat at the sapwood long after the tree is cut down. So I prefer to avoid or remove the sapwood.
WOOD MOVEMENT DEFECTS
When lumber isn’t stacked, sealed, and dried properly it is prone to move in all sorts of strange ways:
Checking happens when a board dries too quickly or unevenly. The cracks move along the board. So it’s best to avoid these boards. If you are cutting your own lumber from a tree, checking can often be prevented by using a good quality wood end grain sealer (like I mentioned above)…the red stuff painted on the ends of boards in many of the above & below photos. Lumber should also be stacked with “stickers” or spacers of even thickness, with weights on top.
TWIST & CUPPING
When green (wet) boards aren’t properly stacked they will cup or twist. Cupping is when the board turns into a cup shape (see above). Twisting is when board ends twist different ways. It takes a lot of work to plane out the twisting or cupping. I don’t always turn down free wood that is twisted or cupped, but I won’t buy it.
Bowed boards are like a bow that you shoot arrows with (see above). To me, this defect is a bit harder to correct for than twisting or cupping. So I avoid these boards…unless they’re free (like the above lacewood board was).
Crook is similar to bow, but the wood arcs the other way. This is an easier defect to fix because it only involves jointing the board’s eges…which I do anyway.