Air drying times can vary with what climate they are drying in. If the wood was green(30%+ moisture) and has been cut down to 8/4. It will be drying for at least 12 months before it has become somewhat dry 12-16%. This is a dangerous period to have wood cut to dimension because it will shrink, and is prone to cracking as it shifts through high imbalances in pressure(core to shell). This is when woods crack and split. The wood probably needs another 6-12 months beyond that period to dry to a fully stabalised piece. Fresh cut wood is risky, and of course with the risk the price(value) drops greatly. I would not waste time with green wood if you do not have an absolutely compelling reason to buy it(the piece is very special), and you have no need to use it for a couple years. To test moisture you can pick up a moisture meter(less expensive ones (under $50) can be purchased at rocklers,woodcraft etc...). You can also monitor weight, but this takes some time and experience.
Peace,Rich
Thanks Rich, I suspected as much. A couple months of air drying didn't sound like a lot to me, especially not knowing how fresh the lumber was before the blanks were cut. I was thinking maybe I might buy a couple, get a meter and monitor the wood's progress. I have a lot of projects in mind and having some wood ready in 6-12 months would be fine for some of them.
I was also thinking, can you dry blanks yourself using an oven or the like? Just popped into my head. Probably a dumb idea.