Air Drying Wood ?

JimmyC · 02-22-2008, 01:32 PM

Hello all,

If I purchase air dried wood, or even green wood, will I be able to keep it in a shed while bringing down the moisture content (what %MC), then do the final drying in a controlled environment. Or should I do some kiln drying.

The woods in question are below:
-ERC
-R. Oak
-W. Oak
-Maple (hard and soft)
-Sycamore
-Cherry
-Walnut

Right now I am mostly interested in Cherry, but other woods do sometime become available. For out side drying, I have a 10 x 20 area that is covered by roof, but open on three sides. For inside, it's a pole barn style building with a de-humidifier.

Thanks all,

JimmyC

PeteQuad · 02-22-2008, 02:30 PM

Sure, there's nothing wrong with air drying wood, it just takes longer. I was planning to do some air drying outside just using a piece of plywood on top. I think people shoot for 6-9% or something like that, but you could bring it into the shop when it gets close.

JackLeg · 02-22-2008, 02:45 PM

Jimmy: Send me your e mail address and I'll send you some good info from Gene Wengert about drying eastern hardwood lumbers.

I cant figure out how to attach it here.

DaveO · 02-22-2008, 06:15 PM

Originally Posted by JimmyC

Hello all,

If I purchase air dried wood, or even green wood, will I be able to keep it in a shed while bringing down the moisture content (what %MC), then do the final drying in a controlled environment. Or should I do some kiln drying.

The woods in question are below:
-ERC
-R. Oak
-W. Oak
-Maple (hard and soft)
-Sycamore
-Cherry
-Walnut

Right now I am mostly interested in Cherry, but other woods do sometime become available. For out side drying, I have a 10 x 20 area that is covered by roof, but open on three sides. For inside, it's a pole barn style building with a de-humidifier.

Thanks all,

JimmyC

Jimmy, air drying is best done in an environment like you've mentioned. It is best to get good air flow throughout the stack. Air drying is only going to take you down to around 12% MC. You can do more drying in a climate controlled environment similar to the environment that the final product will reside in. That will take time. The benefit that kiln drying offers is the "sterilization" of the lumber from bugs and a faster way to get to the desired MC of around 7-8%.
You should have no problem air drying any of the species that you mentioned and all would benefit from air drying before being finished off in a kiln.
Dave

scsmith42 · 02-23-2008, 01:08 AM

Originally Posted by DaveO

The benefit that kiln drying offers is the "sterilization" of the lumber from bugs and a faster way to get to the desired MC of around 7-8%.
Dave

Dave, there is one other key benefit from kiln drying, and that is the control that it offers you over the entire drying process. Most hardwoods have a "maximum safe drying rate", usually expressed as the percentage of moisture content reduction that can be safely obtained per day. Exceed that percentage - or come in well below it - and you risk damaging your wood. Not all of the wood may get damaged, but the percentage that does is referred to as "degrade".

A good kiln and kiln operator will make several changes throughout the drying cycle in order to keep the drying rate within safe limits. These changes will usually include - but not be limited to - temperature, relative humidity, and air flow through the stacks.

Most degrade occurs when drying from green to 35% MC, but it doesn't show up until the wood is much dryer.

You are correct in that air dried wood will equalize our around 12% in our area - but only during the winter. Typically it will be about 4 percentage points higher in the summer due to the higher ambient humidity.

Having said all that, drying your own wood is very rewarding, as it adds one more dimension of "I did that myself" to your woodworking project.

Cheers!

Scott-

JimmyC · 02-23-2008, 07:58 AM

Thanks All,

My problem is that I would like to eventually keep about 200bd/ft of different species on hand for future projects. Most of it would have to be stored in a roofed area with three open sides for the majority of the time.

After bringing the MC down to air dried levels, or even after having it kiln dried, should I still keep it stickered or at that point could I just pile the boards on top of each other.

I'm thinking about eventually building walls around the three open sides, and not sealing it tightly (open eaves, maybe even bottom), how would this affect the storage end.

Thank you all,
Jimmy

DaveO · 02-23-2008, 08:39 AM

Originally Posted by JimmyC

After bringing the MC down to air dried levels, or even after having it kiln dried, should I still keep it stickered or at that point could I just pile the boards on top of each other.
Jimmy

I know that there is no reason to keep KD stock stickered, but you would want to store it in an envirnoment that would have the same EMC (inside, climate controled). I would think that you would still want to keep AD stock stickered if you were continuing to store it outdoors or in. But I am not sure.
Dave

PeteQuad · 02-23-2008, 09:21 AM

By the way, I've been looking at this stuff for air drying:
http://www.shadedri.com/index.html

JimmyC · 02-23-2008, 12:12 PM

Pete,

Thanks for the website, I've seen people using landscape cloth,because they couln't find that stuff.

Jimmy

PeteQuad · 02-23-2008, 12:18 PM

It doesn't look like they have an online store, I was just going to give them a call. Here's the link of the place I was going to buy some anchorseal from (to seal the ends); they do have an online store:
https://www.uccoatings.com/uccoat.php

Turtlewood · 02-23-2008, 12:36 PM

All,

I understand the benefit of sterilization with KD lumber.

But won't the piece of KD lumber with a low MC left in the same environment, say inside your shop, as an AD piece of lumber equalize to the same MC over time... say after a year.

Meaning, if you don't use your KD stock right away, won't it equalize up to the environment that it is in? And isn't this the same operation that AR lumber stored right next to it is doing, just from the opposite direction?

I have some KD stock that I bought 2 years ago on a rack in my shop. I would imagine that it's MC has risen to equal the shop, correct?

-Kevin

JimmyC · 02-23-2008, 12:53 PM

Your KD is fine and should be the mc of it's environment. Sterilization is one aspect of KD but so is the Stabilization of green wood.
The more info I can get, the better.

Jimmy

jeff... · 02-23-2008, 05:51 PM

Originally Posted by Turtlewood

All,

I understand the benefit of sterilization with KD lumber.

But won't the piece of KD lumber with a low MC left in the same environment, say inside your shop, as an AD piece of lumber equalize to the same MC over time... say after a year.

Meaning, if you don't use your KD stock right away, won't it equalize up to the environment that it is in? And isn't this the same operation that AR lumber stored right next to it is doing, just from the opposite direction?

I have some KD stock that I bought 2 years ago on a rack in my shop. I would imagine that it's MC has risen to equal the shop, correct?

-Kevin

Good thread here and Yes Kevin your right - take KD leave it outside and it picks up moisture, throw it in the pond it gets wet, store it in a climate controlled environment and it equalizes over time with that environment.

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