Moisture Content

[Chuck B.]

I got a great new planer for Christmas. I have had a jointer for awhile now. I got both of these so that I could go to this great little local sawmill and buy rough cut hardwoods of all types for use in my projects.

I am planning a project that I want to use hard maple on. I called the mill to ask the guy what he had. He said he had some sugar maple in the right sizes and quantities.

All of his wood is air dried (outdoors, under cover) and he said that this stuff has been drying for quite some time. I asked him if he had any idea what kind of moisture content I should expect and he told me that 15% is considered good for air dried (we are in the Hudson Valey part of NY and we get very wide variations in humidity between winter and summer). All of this made me think that I should invest in a moisture meter, so I bought one on E-bay.

I was hoping to just buy the wood this weekend and get to work on my project immediately. Now I am wondering if I need to bring the wood into my house and let it acclimatize before I start working on it.

What kind of moisture levels should I look for before I start building and what can I do to prevent moisture problems in this wood later on in its life as an indoor tabletop? Any opinions or advice will be appreciated.

Thanks, Chuck

[Mike G]

8% is considered ideal for furniture making in about 80% if the US. We, you and I, are located in part of that 80%.

It's about 6% in most of the south west and 11% in a good part of the southern tier of states.

If someone wants to argue those figures talk to Tim Begnal.

Ref- Page 88 "The Woodworking Hand Book" Tim Begnal..

So, if you are buying at 15% you will have to let it dry a bit more and I would expect to pay less per board foot then I would at a hardwood supplier selling 8% MC wood in the same grade.

Good luck

[JGS]

[jev]

You've got a moisture meter so meter some wood samples that have been laying around your shop for a while and see what their EMC is. Compare that to wood you buy.

[Mark Shafer]

I don't want to brag, but I really have built hundreds of tables -- all kinds. I have always regretted any time I pushed the limit with moisture. When I laminate a large panel like a table top I get really picky -- absolutely nothing over 7% moisture is my rule of thumb, maybe 8% on a small panel. Air dried is never sufficient unless it's years in fairly arid ambience. Not many have that kind of storage space or patience these days, so build a kiln or find one to take your material to. When it comes out of the kiln, cut a board well away from an end to test the moisture. And when you finish your project, be sure to seal the underside WELL, not just a sealer coat but a couple or three finish coats too. You value your reputation for the future. Don't let ANY problems come back to make trouble for you.

Good luck!

Mark Shafer

[Chuck B.]

Mark, Do you have any suggestions how I would locate a kiln in my area? Thanks, Chuck

[George]

Lumber, Wholesale - in the pages.

However, it matters not how the wood got there, the RH is what matters. Kilns are not now, nor have they ever been needed to get wood to the EMC that matches their environment. They'll get there on their own, and in better shape, in the opinion of many, for the slower method.

Oh yes, with THREE meters up at the University, air-dried ( 1 1/2 years) wood in my winter basement is ~4%.

Build loose in low, tight in high humidity, but always build smart, because the humidity will change.