There are numerous ways to season wood such as microwave drying, air drying, boiling and kiln drying. I find that using the kiln seems to give the best results for my own wood. If you do try to air dry the wood then you need to be aware that the moisture content will only drop to the surrounding moisture content in the air, which in most cases may not be sufficient.
Safety Warning
Turning can be dangerous. I expect you to be fully aware of the potential dangers and to take adequate precautions. If you follow any of the advice I have given you do so entirely at your own risk and I cannot be held responsible for any injuries or mishaps that may occur.
The Woodturning DVD called Lacework Techniques with Yvonne Arlott continues to sell all round the world.
