Air Dry vs, Kiln Dry
 

I have an opportunity to purchase 200 board feet of "air dried" white
oak for about $1.50 per board foot. The wood has been air drying for
11 months and I went there with a meter and it has an adjusted for
temperature moisture content of 8%. It is rough cut to 4/4 but I have
a planer so that is not an issue.

I want to make a roll top desk and my question is simply am I making a
mistake in not getting kiln dried lumber. What can I expect after it
begins to dry in the home after the desk is made?

Would appreciate any experienced comments.

Cut a piece in half and see what the moisture is inside.

--

Rumpty

Radial Arm Saw Forum: http://forums.delphiforums.com/woodbutcher/start

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"JJM" wrote in message
...
I have an opportunity to purchase 200 board feet of "air dried" white
oak for about $1.50 per board foot. The wood has been air drying for
11 months and I went there with a meter and it has an adjusted for
temperature moisture content of 8%. It is rough cut to 4/4 but I have
a planer so that is not an issue.

I want to make a roll top desk and my question is simply am I making a
mistake in not getting kiln dried lumber. What can I expect after it
begins to dry in the home after the desk is made?

Would appreciate any experienced comments.

JJM asks:
I have an opportunity to purchase 200 board feet of "air dried" white

oak for about $1.50 per board foot. The wood has been air drying for
11 months and I went there with a meter and it has an adjusted for
temperature moisture content of 8%. It is rough cut to 4/4 but I have
a planer so that is not an issue.


I want to make a roll top desk and my question is simply am I making a
mistake in not getting kiln dried lumber. What can I expect after it
begins to dry in the home after the desk is made?

A lot depends on the accuracy of your meter. With rough cut material, I
prefer a pin style meter, and I like one that lets you select for
species. Those two things can make a significant difference.

8% sounds a shade dry for air dried oak at just 11 months, but it is
winter time, when humidity is lower (or so it is said: this has been a
very, very wet winter here). You might want to take a #4 plane along
and skip plane some surface areas to see about getting a more accurate
reading.

Put the oak in your home for a month or two before doing anything final
with it--some heated area in the basement is fine. Then check. The wood
needs to acclimatize, anyway, with a minimum of a week indoors where it
will be worked before serious machining starts.

Most of what I've built in the past 20 years has been built with air
dried lumber, and it has never given me a problem my own stupidity
didn't cause. I try to get it under 10%, acclimatize as above, and
ignore the rest. That system, or lack of a system, usually works very
well.

Kiln dried lumber would work well, but it won't work any better, and,
if the kiln operator is not experienced and careful, could well be
worse.

I've made stuff with air dried walnut and cherry, seems the colors are
much brighter than kiln dried. I read somewhere that kiln dried lumber
gets steamed at some point in the process, bleeding out some of the
natural dyes.

Sounds like a good price.

It was somewhere outside Barstow when JJM wrote:

I have an opportunity to purchase 200 board feet of "air dried" white
oak for about $1.50 per board foot.

That price ? So get it. Work out what to do with it later.

The wood has been air drying for 11 months

Sounds a little young as yet. But then I've rarely bought timber in
that quantity and started using it immediately. Stack and sticker it
in similar target humidity to where the finished piece is going to be
used, then ignore it for a few months.

8% humidity sounds unusually low that quickly, but then it's a funny
time of year.

Personally I take almost no interest in moisture content at all. I
don't believe it's possible to measure it accurately enough and the
practical effects are better if you concentrate on air humidity and
allowing enough time for equilibrium (read Hoadley for why this
works).

It is rough cut to 4/4 but I have
a planer so that is not an issue.

I'd prefer to saw it to 8/4 first. There's always some cupping in
drying and you lose less timber by flattening two sides then re-sawing
it than you do by having to flatten four sides on an equivalenet
quantity of timber.

You'll be wanting a chip collector too, if you have that much to
thickness. Know any potters ? One has just taken all my oak planer
shavings to use for raku firing.


I want to make a roll top desk and my question is simply am I making a
mistake in not getting kiln dried lumber.

Kiln dried timber is _NOT_ better. For softwoods in particular it may
be quicker (cheaper), more predictable (cheaper) and may "set" some
resins. But mainly it's there to make it cheaper.

If this is your first time using a large quantity of "primo" timber
like this, then a copy of Hoadley's "Understanding Wood" would be a
very good thing to read through beforehand.