Q: I've noticed that large, old Black Jack oak, which grows in Oklahoma to very large size, often has heartwood with amazing color and figure, and I've tried many times to dry the stuff and use it for accent wood. The problem is, the wood always checks, and splits, even with the slowest (two years) air drying. I assume this is due to the slow irregular growth habit of the tree and the density of the heartwood in older trees. Any suggestions?
A: In older trees, there are several special characteristics of the wood that can lead to processing problems.
First, many older trees are more open grown with large branches. So, there is more cross grain, leading to excessive warping (compared to trees grown in a competitive forest, where most branches are at the top of the tree).
Second, it is not unusual for an older tree to develop more cross grain in the lower part of the stem with fluted butts, undulated annual growth rings, and so on.
Third, often the older trees are in areas that have been grazed or the adjacent soil has been farmed. This activity leads to damage of the roots, allowing bacteria to enter the tree. It may take 70 years or more for the bacteria to affect wood quality in an oak tree. Quality losses include more color streaks, weaker wood (more cracks and checks, and even wind shake in the standing tree), smelly wood, and higher initial moisture contents.
Try very slow air drying. Cover the pile partially with plas tic burlap or put it in a shed that is partially closed. Be especially careful of those hot, dry windy days. Keep the piles covered and protected. Cutting the lumber in the winter can help, because the first few months of drying in cold weather is more gentle than summer weather.
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