Wednesday, April 12, 2017

a maple bowl

The spigot remaining at center allows the use of a tail stock.
Part of the teacher's challenge is to learn, so I am turning a large bowl from green maple. For those unfamiliar with woodworking terminology, green refers to the fact that it's still wet wood, freshly cut.

The advantage of turning green wood is that the cells are full of water, and just as a ripe tomato is easy to cut with a knife and a dried tomato takes greater force, the bowl gouge cuts quickly through green wood. It leaves ribbons of pasta like strings of wood at my feet and hanging from my shoulders as I turn.

The disadvantage of turning green wood is that as the bowl dries, it will no longer be perfectly round. As cells shrink in size due to loss of water content, and as the cell walls harden, the shape of the bowl will become oval.

If I were to simply let the log from which this bowl came dry prior to turning, it would be severely cracked. So the strategy here is to leave the bowl shape thick enough that it can be turned again later after some of the distortion of shape from shrinkage takes place.

Many skilled turners follow this strategy, turning in two stages, the first being wet, and the second, dry.

Much of the wood turning art concerns how to hold material on the lathe while the gouges are used to form its shape. I formed a dovetail recess in the bottom of the bowl early in the process so it can be held by the lathe chuck. On the inside of the bowl I've left a spigot that allows a center in the tail stock to give strength to the mounting as the outside of the bowl is turned again to its final shape.

Part of the mystery of turning is that there are always things that can go awry. The grip of the chuck can fail. The gouge, poorly controlled can catch and dig chunks from the wood. And while a bowl may seem like such a simple thing, a successful one, or even one that has come this far is not something to take for granted. Each and every second of turning takes intense attention. That is one reason turning wood on the lathe is good for kids. Each second matters. The effects of mindlessness become readily apparent.

My thanks to Lin and Klaus for the lovely piece of wood.

Make, fix, create, and encourage others to learn likewise.

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