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Creation:
Essentially,
all of my turnings come from "green" wood. One of my
greatest pleasures is the pursuit of turning stock during the winter
months. My two grown sons and I schedule outings to cruise selected
areas of woodland in the middle Georgia area. We are particularly
blessed with hardwood species. I currently have turning blocks of
walnut, cherry, local red maple, pecan, red cedar, persimmon, mulberry,
hackberry, hickory, beech, chinaberry, ash, and oak. My preference is
to collect in areas that have been clear cut for timber. It is not
uncommon to find “tops” on the ground that are more than twelve inched in
diameter. You will also find an abundance of crotch wood and the
occasional burl since these are of minimal value to the sawyer or others
searching for firewood.
Once
harvested, I will prepare the wood for seasoning. The procedure I use
is similar to that discussed in woodturning books and on-line
articles. My preferred chainsaw is equipped with a 20 inch bar and a
3/8 inch wide chain. This combination yields a sufficiently wide kerf
to minimize binding while ripping a log segment. I try to “read” the
log so that any unique aspects are preserved in the center of a turning
block and the heart of the log is cut out as well. The size of the
turning block is determined by either the diameter of the heart wood or the
swing of your lathe (24 inches in my case). I generally measure the
diameter of the heartwood, and then add about 4 inches to establish the
length of the flitch to account for end grain checking. I then
remove the sap wood from the blocks and seal the end grain with a
commercially available sealer.
Since
I like the look of spalted wood, I process most species in a way that
allows me to control the degree of deterioration over time.
This is accomplished by sealing the green wood in plastic
bags. The time in the bag depends on the species of wood and the
climate (winters are mild in Georgia). It may be as little as six
months to over two years.
I
check on the seasoning process by rebagging blocks every six to nine
months. When the desired “look” is achieved, I move the pieces to
ventilated storage racks and store them under tarps until I am ready to
turn them. As the moisture level in the turning block drops the
spalting (rotting) process stops. Learning how to manage this is key
to being able to safely process spalted wood on the lathe.
I
have found that bagging turning blocks is beneficial in general. Six
months in the bag seems to improve the overall dimensional stability of the
wood – less warpage during drying of rough turnings.
Next
installment: Safety
considerations when turning spalted wood.
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