I have a lot of logs that have dried for centuries, begging to be turned into bowl. Bear with me as I'm new to bowl turning. My lathe has a 12 inch swing. Diameters of logs can run up to eight inches. What would be the maximum length of a small log for turning to a bowl? 8x8? Larger logs would be cut and rounded on the bandsaw. Hope I'm making sense. Thanks.
I don't consider myself a "bowl turner" although I've turned a bunch of bowls, dry and green. What kind of bowl?
How long is a "century"? And kind of wood? Have the logs been kept off the ground out of the sun to prevent rot? Those sitting on the ground may be decayed - cut through one to inspect. Or if lucky, spalted! If unlucky, maybe firewood.
Could turn an 8" diameter end grain bowl, the length you cut and the depth is up to you. Could leave the bark on the rim or make a smooth, turned rim.
Could cut down the pith with a bandsaw or chainsaw then you'd have about 8" across to work with, so if centered about an 8" length would work. Turning with the pith at the bottom or the pith at the top makes a difference in both size and the shape of the rings inside - they might be distinctive for some species. Turned with the pith down would made a smaller diameter bowl, depending on the depth.
Some people turn a bowl and leave the pith in it somewhere. This, depending on the wood, can be great or cause a bunch of cracking.
With plenty of small logs and new to bowl turning, you have the perfect opportunity to experiment with all different ways! There are plenty of books likely youtube videos that could help. Or someone in a local club (Chatanooga?) might be thrilled to provide ideas and even mentorship.
But you said ""logs that have dried for centuries." Should stay away from cracks on the end grain. If you see cracks one thing to do is to cut back with the chainsaw until you see no cracks, then cut a thin slice (maybe 1/4" thick" and bend it. This will expose hidden cracks. If any, repeat until the thin slice is solid.
If you see cracks down the side, you can cut off say a 10" length in away from the ends and see if you can make another cut down the crack, giving you two solid halves. If there is more than one deep crack on the outside, it may be too late.
If you need wood for bowls, take a drive up 75. I have walnut, cherry, ERC, and more on the ground and some dry bowl blanks. A dry piece of mahogany, walnut, or cherry about 2" thick can make nice shallow bowl. The design is up to your imagination. If looking for ideas, there are books and an internet full of those!
This is one of my very early bowls made from dry 2" thick cedar. Thicker wood not needed for a small, shallow bowl!!
I think this one was from 3" thick cedar:
And this was my very first real bowl, after practicing on a piece of red oak. Cherry, about 2" thick.
With a few exceptions, most of my bowls are from dry wood.
That said, I'd rather turn spindles!
An 8" diameter log cut down the middle can make some VERY nice spindle turning blanks!
