Friday, May 19, 2006

Turning ancient wood

Most woodturners are very happy when they are given a 30 inch diameter log to work with, but Don Thur was stunned when carbon dating at the University of Toronto revealed one log he had acquired was 8,637 years old.

The white pine was discovered sixteen feet down by a friend digging a pond. The tree itself was 261 years old when it fell. The Huntsville Forester explains a theory scientists have for why the log is so well preserved. It is also thought to be the oldest wood find in eastern North America.

I was interested in finding out more about this wood and how well it turned, so last night I spoke with Don by phone. He told me that the largest log was somewhat oval due to wind pressure, and measured 30" by 25". Apart from the outer inch or so, the logs were soaking wet and smelt disgusting. Don was surprised to find that there was still tension in the wood when he turned it.

The log had some ring checks and radial cracks, probably caused when the tree was knocked over, and Don incorporates and enhances these features in his work. There was also some attractive figure around the knots. The wood has a green / orange tint. There was no resin apparent in the wood. It has turned out to be quite fragile material, and even with his solid design style, several pieces have had to be glued back into place.

Don regularly uses Pentacryl to stabilise his work, but found a problem with this wood. The Pentacryl would not dry, and the manufacturer suggested this was due to the lack of resin and sap in the wood which normally react to emulsify the Pentacryl. The problem was fixed by mixing 50/50 with mineral spirits.

The bowls made from this wood are selling well. Don has already sold the four largest bowls to past customers; one of these patrons is planning on donating one to a museum and one to a local government office where it will be placed on public display.

Meanwhile scientists are continuing their study of this unique piece of wood and hope to publish their findings in about 3 years time.


keith said...

thats pretty cool, here in Ireland we have oak and yew which has been buried in our peatland bogs from anywhere to 6-8000 years. Machines that cultivate the bogs regularly hit the logs and dig them up to dump them to one side out of the way. As soon as they are exposed to the elements they start cracking and splitting, over a period of time of course. I have been fortunate enough to get 3 large bog yew logs which are still strangely solid, only acquired them recently and they haven't been cut up yet

Derek Andrews said...

Lucky you! I have heard of Irish turners using bog oak, but I never heard of bog yew. Have you cut into any of it yet? What does it look like?