How long does a piece of green oak take to season? It’s a question that I am frequently asked and the stock answer that most of us give is that it seasons an inch a year. So if you have board 25mm thick it will be pretty much fully seasoned in 12 months whereas a thicker 100mm piece would take around 4 years.
While I was making the bench for the One Oak project I took the chance to measure the moisture content of the timber I was using. When it was cut in January a year ago the timber had a moisture content of around 43%. It was then sawn in late February and stacked outside to start to season. I picked up the boards I used in my bench in November so they had had 9 months of seasoning. The 30mm thick boards were down to 18% moisture contect – that’s pretty much fully seasoned for air dried timber and I suppose where I would expect them to be after a dry summer. The thicker 80mm board was around 29% m/c in its centre, quite a bit drier than I expected but perfect for the type of furniture I make. It is still easy to work with being nice and soft, and much of the shrinkage that occurs as it dries has already happened, meaning that the furniture won’t move around too much or split.
It still going to take another few years for those thicker bits to fully season.