From Logs to Lumber
[From Jeff Schmaling] I have a standing, dead red oak on my property that’s straight, about 24 in. dia. and about 40 ft. tall. I’d like to harvest the tree for use in my shop, but I’m not sure how. Can I have it rough-cut into planks right away, or should I leave it in logs to season? If so, do I need to cover the ends with preservative? Any advice would be appreciated.
Question: [From John Norris] This winter, a neighbor let me harvest a black walnut tree he wanted removed. I sawed it down, hauled it home and sealed the ends with hot wax. What do I do now? My current plan is to slice it myself with a chainsaw milling attachment. Should I do this as soon as possible, or let the log age for a while? My first thought is to slice it into 8/4 slabs to cure. Is 8/4 the optimum thickness? The projects I have in mind for this wood will use boards no thicker than 3/4 in., and I may want to slice some of it into veneer. I have tools to resaw and mill rough lumber up to 12 in. wide. After slicing it into slabs, should I rip it into 12 in. widths as soon as possible or let the rough slabs cure? How should I dry the boards?
Jeff Schmaling, Libertyville, IL
Logs are perishable commodities, and warm weather, bugs and humidity can cause deterioration very quickly. The rate of degradation varies greatly from species to species, even from log to log depending on storage conditions.
I have never had much luck sawing red oak that’s been dead on the stump for more than a few months. The sapwood breaks down rapidly as microorganisms feast on the sugars, and the dead tree becomes susceptible to insect infestation. If you see fungal growth on the side or ends of the log, the decay inside is quite advanced.
Even so, sapwood can be edged off at the mill, rotten parts can be trimmed away and even an insect-infested pile of lumber can be fumigated. You just have to ask yourself, “Is this lumber worth it?”
Unlike red oak, black walnut trees that are dead on the stump may remain in near perfect condition for years and often gain a rich reddish-brown color. A friend of mine who built a house on his family’s farm in Maryland told me about a walnut tree that he sawed for paneling in his den. It had been standing dead in the middle of a field for at least 10 years before finally falling over. His father dragged it to the edge of the woods with a tractor and left it in the shade where it lay for another 15 years before being sawed into boards. The bark and sapwood had completely rotted away, but the heartwood was as good as the day the tree had fallen.
Regardless of the species, seal the ends of a log as soon as the tree is felled to prevent excessive checking. I use Anchorseal, a wax emulsion paint (U-C Coatings; 888-363-2628).
Chainsaw mills consume an incredible amount of wood with each pass, so I recommend calling Wood-Mizer Products (800-553-0182), a company that manufactures bandsaw mills. The company may be able to provide referrals to local sawyers who own their mills. A bandsaw mill will yield up to a third more lumber from a given log than a chainsaw or circular saw mill.
Your next decision is how to have the wood sawn. You basically have three choices: sawing for grade, quartersawing and flitchsawing.
Sawing for grade involves opening up all four sides of the log and picking the clearest face to saw until it is no longer the clearest. Then you flip the squared log (it’s called a cant) to the next best face, saw that face, and so on. Your sawyer will continually look for the highest grade board to pull from the log.
In red and white oak especially, quartersawing reveals a lovely medullary ray flecking. I quartersaw oaks that are reasonably clear and at least 20 in. dia. on the small end of the log.
In flitchsawing, also called sawing through and through or sawing en boulle, the sawyer starts on one side of the log and saws the boards in succession. This might be the best choice for the walnut because there is a considerable premium attached to the wide boards this method produces. If their width exceeds your planer’s capacity, you can always find someone with a wider planer, surface them by hand or rip them down when you’re ready to use them.
There are two potential problems with cutting stock thick and then resawing it. First, doubling the thickness of a piece increases its drying time by 250%. Second, if you take your boards to a kiln for drying, the likelihood of introducing stresses increases with the thickness of the stock. I suggest sawing the lumber a fat 1/4 in. thicker than your anticipated finished dimension.
Drying is tricky. There’s a lot to learn. Two excellent introductory books on the subject are The Conversion and Seasoning of Wood by William H. Brown (available from Bailey’s Woodsman Supply; 800-322-4539) and Wood and How to Dry It (The Taunton Press; 800-888-8286).