Need your feedback: Climate control vs. bowing/warping

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Forum topic by Randy Sharp posted 06-18-2008 08:54 PM 2432 views 1 time favorited 15 replies Add to Favorites Watch
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Randy Sharp

363 posts in 3871 days

06-18-2008 08:54 PM

Topic tags/keywords: question

Need some feedback, fellow woodworkers.

Let’s say I buy a 1×8x10 red oak board from the controlled climate of my local home improvement store. The stock is straight…looking good and square to make a cabinet door frame (flat panel door using 1/4” plywood insert).

My shop is not climate controlled and after a day or so in Mississippi heat and humidity (85 degrees at say, 70%), it begins bowing and/or warp. A friend recommends I slightly dampen the cupped side and lay if flat to correct the problem. No good. After it bows, taking it back to a climate control unit is too late too. It won’t go back straight.

What I’m thinking is that I keep it in my climate controlled house from the store until I’m ready to cut, take it to the shop and either build the frame immediately, or take the pieces back inside for assembly later. The board will spend less than two hours out of climate control during cutting.

Does that sound workable, or are there other solutions?

Thanks, Randy

-- Randy, Tupelo, MS ~ A man who honors his wife will have children who honor their father.

15 replies so far

View GaryK's profile


10262 posts in 4187 days

#1 posted 06-18-2008 08:57 PM

I think that first I would just wait a week and see if it equalizes. It will probably flatten out on it’s own.

Give that a try before you do anything else.

-- Gary - Never pass up the opportunity to make a mistake look like you planned it that way - Tyler, TX

View Greg Wurst's profile

Greg Wurst

795 posts in 4031 days

#2 posted 06-18-2008 09:40 PM

I usually cut wood on my table saw in the garage. I leave the wood in my house until I cut it and take it back in immediately after I am done. Wood I used to leave in the garage would warp like that for me, and keeping it in the house has greatly minimized that problem.

-- You're a unique and special person, just like everyone else.

View Russel's profile


2199 posts in 4138 days

#3 posted 06-18-2008 09:56 PM

I’ve had some luck clamping boards to a flat surface for a few days while they equalize to the new environment. It’s worked for twisted boards up to 5 feet.

-- Working at Woodworking

View Randy Sharp's profile

Randy Sharp

363 posts in 3871 days

#4 posted 06-18-2008 10:19 PM

I guess once you rip it, internal stresses can cause it to warp and cannot be reversed?

-- Randy, Tupelo, MS ~ A man who honors his wife will have children who honor their father.

View Catspaw's profile


236 posts in 4014 days

#5 posted 06-19-2008 01:25 AM

This is a concept I can never understand. Everybody spends all this time trying to control the environment of the wood, hoping nothing happens to it.

What happens when you make something out of it and send it off some where and the new conditiions aren’t the same? What happens if your A/C breaks down for a few days. Or the heater. Will the piece of funriture suddenly go all warpy?

I see no sense in building with something that is going to warp. IMHO, if it’s going to warp when I don’t control all the environmental conditions, I don’t want to use it in anything. It would seem to me if it’s moving that much, there are internal stresses that you won’t be able to get rid of short of using it in short lengths and such.

And finishing (sealing) the piece is only marginal help.

-- arborial reconfiguration specialist

View BroDave's profile


107 posts in 4013 days

#6 posted 06-19-2008 02:14 PM

I believe that internal stress which causes a piece to warp is beyond anyone’s control, but warping due to environmental conditions can be controlled, at least while you have the project in your hands.
My thinking is if I can store and build a piece under the same conditions as it will be normally subjected to in someone’s home then the movement will be minimal, especially if I have finished/sealed the piece to prevent it from absorbing moisture.

Anything finished with poly is going to absorb and loose moisture almost as if it were never finished, unless it built from plywood or MDF which doesn’t move much to start with.( China products not included)
I stopped using poly finish, Shelac and Laqure only on solid wood for me.

Of course I may be way off the mark in my thinking, but it makes me feel better. :)

-- .

View Randy Sharp's profile

Randy Sharp

363 posts in 3871 days

#7 posted 06-19-2008 03:27 PM

My thoughts are along the same as BroDave. Per Catspaw, you’re right in the “hoping nothing happens to it” theory. If I spend $40 on a single board, in the back of my mind, I’m saying “I hope it’s a good one this time.” Is it a question of luck, or are there things the average guy can look for in the wood that (i.e. grain pattern) that can tip him off?

-- Randy, Tupelo, MS ~ A man who honors his wife will have children who honor their father.

View jcees's profile


1070 posts in 3998 days

#8 posted 06-19-2008 09:08 PM

I live in FL so I know a thing or twelve about moisture uptake and release. That’s why I don’t buy “finish” wood from the Big Box store anymore. They want too much for it anyway. BUT if I were stuck with that as an only option then I’d treat the stuff like it was rough. In other words, it’s going to get a lot smaller before I’m through. I would cut my parts oversize, let them stabilize in the shop then square the pieces to almost finish size and let them settle a bit more before trimming them to final size. Taking it in steps is the surest way I’ve found to deal with the demons of distortion. Hope this helps.


-- When one tugs at a single thing in nature, he finds it attached to the rest of the world. -- John Muir

View dirtclod's profile


169 posts in 4059 days

#9 posted 06-20-2008 03:17 PM

Don’t let it acclimate to your uncontrolled shop. That’s asking for trouble no matter what form the wood is in. Your shop is not dry enough to leave wood in it, unless you plan on storing it there and putting it in a kiln, or other drying method later, before you use it.

You’re right – move it to a controlled environment when you are not actually working on it.

-- Wonderful new things are coming! - God

View davidtheboxmaker's profile


373 posts in 4004 days

#10 posted 07-04-2008 10:19 AM

I don’t have massive climatic effect on the timber I use, but I do take steps to let the wood settle before I use it. Typically, I buy some wood, then let it sit in my workshop for a month or two, then resaw and let it settle for another month or two before taking it down to final thickness. Having done that, I then let it lie for a while before I use it. Having done this, which mainly consists of leaving the wood alone for a time, I then check the timber is flat before I use it. I do get the occasional piece that twists so as to be unusable due to internal stresses. That becomes scrap. The vast bulk of timber I use does not show any distortion, and is stable when used.

View accalades's profile


5 posts in 4261 days

#11 posted 07-06-2008 05:37 PM

always upsetting.

-- chris lambkin

View Al Killian's profile

Al Killian

273 posts in 3952 days

#12 posted 07-06-2008 06:56 PM

I try to let the wood sit for a week or two. Then use it uo after it is cut or there is a good chance it will move more.

-- Owner of custom millwork shop

View John Fry's profile

John Fry

74 posts in 3899 days

#13 posted 07-08-2008 04:36 AM


The question nobody has asked is,..... Did you store the wood properly?

The biggest problem people have with wood warping after getting it home (or after freshly milling), isn’t just the change in RH conditions, it is the way it was stored! How did you store your new board? Sitting on the bench? Stacked against another board vertically? If the board is stored in a position that only lets air get to one side, it will change moisture content on that side and the other side won’t. This will warp 100% of the time. Did you allow your high humidity air to freely flow around the board for equal exposure?

I know folks will disagree, but I NEVER take the time to acclimate wood in my shop. What is the point? First of all, I can’t afford to sit around and wait week after week, or I’ll never get paid. I live in the high desert of So. Cal. and it is generally around 12 to 12% RH. I have sold furniture to clients in Houston, Washington DC, and upstate New York. These are very humid locations and I’ve never had a call back. Acclimating lumber to my shop and then selling to these locations seems silly!

If you handle and store your wood properly, stack and sticker (or clamp) after milling and exposing fresh surfaces, and keep your material flat at all times during construction, then build with proper techniques to allow for expansion and contraction, you should have no problems. And, you should be able to locate your piece in any climate zone.

I live by the motto…..”The safest place to store your lumber is in your project!”

-- John, Chisel and Bit Custom Crafted Furniture,

View grumpycarp's profile


257 posts in 3944 days

#14 posted 07-08-2008 07:43 AM

The process of kiln drying wood can lead to a condition called “case hardening” which is not at all unlike what happens to metal. Except with metal it is a condition often created on purpose and with an end result in mind. With wood it happens because the wood is dried too fast leading to a situation where the outside and the inside dry at different rates. This causes an imbalance between the two which builds in stress and upon cutting releases those stresses. I have had kiln dried 2×12 western red cedar literally explode upon being crosscut halfway.

Acclimate as you have time and space for. Ensure proper airflow to all sides. Rough mill oversize and allow time to stabilize. Mill to final size and assemble as soon as is practical.

As GaryK said (and I paraphrase) “At first, do no harm” it will probably even out.

The other issue could be stock selection. NO BULLSEYES! Check the grain. Quartersawn stock is pretty darn stable, rift sawn far less so. And anything close to the heart of the tree will just go wonky. Just because it’s on the shelf and expensive doesn’t mean you should use it. I go through this with people on my end constantly.

And lastly, your joinery should allow for wood movement. If the piece is shipped from John Fry’s shop in SoCal at 12% rh to your house in Mississippi it will move quite a bit if made from solid wood. This should be accommodated in material selection, grain orientation and choice of joinery.

Just my five buck a gallon opinion. . .

View Chris 's profile


1879 posts in 4190 days

#15 posted 07-08-2008 03:35 PM

This is the very reason why I buy rough stock now instead of dimensioned. When I started doing this I had far fewer issues. I too live in a VERY high humidity area; roughly 80 to 90% depending on the day.

With rough lumber I can dimension oversize then after the stresses (bowing, warping, checking, etc) occur I have the extra size left to correct it….

-- "Everything that is great and inspiring is created by the individual who labors in freedom" -- Albert Einstein

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