OK here goes all you could ever want to know about wood drying

WAY TO GO TOM!!!!

Robert

As you note, from your research, it's the Scandinavian countries who have shown the most interest in vacuum-aided drying.

Note that _nobody_ soaks things dry. It's all variations on a theme - water is let out of the wood and carried away by the air. Vapor pressure/relative humidity are the governing factors in all drying methods.

Play the distortion figures to get as thin as you can for more rapid drying, but remember the orientation of your annual rings and their relative thickness when you do. Six weeks to EMC on 3/4 of an inch stock is not unreasonable. Translates mostly to a heart-up piece with 3/8 final wall thickness on most northern hardwoods to a foot or so in diameter.

I believe the six week figure to get it totally dry, but I've found that (for me in my little turnery) my best results to date have been with turning to 3/4"-1/2" thick, drying one week with no special hoodoo, just on a bench in the basement at 55*F out of the sun, then turning to final thickness. I do turn pretty thin- average final thickness for most of my stuff ranges from 1/8" to 1/4", generally with a little thicker base. What I find is that they're still a little wet, but any cracks that were going to happen have happened, and they tend to hold together after that week's dry time. It's fun watching them distort as they get thinner, though- I usually turn bowls with the heartwood towards the rim, and they have a pretty consistant distortion across the big three types of wood I turn (maple, birch and willow) after sanding up to 120, I give the rim a little shave with a sharp scraper, and so far there has been little or no cracking. Hollowing's a little different, of course, but it's my current favorite for bowls.

Might have to reevaluate my strategy if I get the giant oak limb we're contemplating removing to build my dad's new deck. It'd be a first if I can get that stuff to turn without exploding, so the drying discussions are welcome.

It's not the heat, it's the (relative) humidity. Keeping them up on the bench is going to give you dryer than leaving them near the floor. If I put mine down too early into that 80% RH, they have time to grow mildew.

OTOH, I have had some surface checks appear after the first week by leaving them up where it's 65%. Those I turn directly to thin for warp and go ~1/4" can be left almost anywhere and do just fine.