Safe moisture content in Ohio

[Matthew Curtis]

What is a safe moisture content (MC) to use? I hear that 10-12% may be ok, but for furniture 8-10, or 6-8%. What is ok to use for small furniture?? I am in Ohio and I would not think that it is possible to get less than 8 or 10% by air drying.

[John Keeton]

Matthew, moisture content, just as a %, is probably not as important as the wood reaching an equilibrium (becoming acclimated) before you build. Truly air dried wood is just that - it has become as dry as the ambient conditions will allow. If those conditions are the same as the final resting place of the furniture, then that is as good as it can get - at least for me. That condition will produce the least wood movement either way.

If you start with wood at 6%, and the equilibrium conditions of the "home" of the furniture will put the wood ultimately at 8%, then you will have expansion. And, vice versa.

[bob hertle]

Matthew,

I'm in southern Ohio and I've built a lot of furniture from air dried oak, cherry and ash that after several years in a barn on stick was at 11% plus or minus. I always brought enough into the shop, and let it further dry to 7-8% which is about as dry as it's going to get. My shop is in a dehumidified basement and the trip from 11 to 7% took anywhere from a month to three months. Might speed that up if you run a fan to circulate air thru the stack. I guess my conservative treatment paid off, because i've never had a top crack, a drawer twist, or any other shrinkage problems.

One exception is a white oak English garden bench I built about 20 years ago. I worked the 11% material as it was, and the bench survives today.

Regards
Bob