Unseasoned timber? But wont it crack?
Congratulations! This is the question I am most often asked when demonstrating Greenwood techniques, and I've got to admit, it is a good question!
For thousands of years man has worked green wood successfully, developing techniques and an understanding of how to overcome problems of timber splitting whilst seasoning.
Sadly, this understanding has been largely lost from common craft consciousness with the advent of electricity and modern seasoning processes.
The reason that timber can split during the seasoning process is due to differential shrinkage: that is it shrinks more in some directions (tangentially), than in others (radially and longitudinally). It is this differential shrinkage that causes the tension, which if not released, may lead to cracking or splitting.
The Greenwood worker however, overcomes this problem by cleaving or splitting his raw timber prior to working it. The wood is split until the required working size is achieved. So the wood is split at least once i.e. into half (and often much more).
This initial cleaving allows the turned (but still green) item to dissipate these tensions naturally, allowing the leg of a chair for example, to change shape during the seasoning process, from a round to a slightly oval cross-section.
For chair components and other items requiring an assembly process, tenon joints are quickly and accurately turned down to their final measurements after seasoning is complete.
So, not only can green timber be used for serious wood turning, but there are, I believe some considerable advantages in using this technique....read on!
