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Warped!!! - joemac - 05-28-2016

I am building an armoire from quartersawn white oak. It is a large piece and is solid QSWO. My problem, and my question has to do with the single door. It is a large piece, 29" X 56" rail and style construction with two panels. The rail and stiles are all 1" thick and the panels are 3/4" thick, setback 1/4" from the front, the stiles are both 6" wide and the top and bottom rail are 6" wide, with the center rail 5" wide.

To make up the panels, I bought a large piece of 8/4", 10" wide by 50" long. I resawed the piece into two 3/4" halves. I then bookmatched the halves forming a large panel which I crosscut into the two panels that I would need. I then sized both panels and left them for a week. From fear of warpage, I clamped them flat on my bench. You guessed it, they both warped. The panels are 18" wide. If I hold one edge on the bench, there is a 3/4" gap under the opposite edge. Since they are to actual size, I can't cut them and reglue.

I have to cut a rabbet around all four panel edges, each 3/8" thick and wide. They will fit into a 3/8" dado which is set back 1/4" from the front of the stiles and rails.

Now to my question: Am I inviting trouble if I force the panels flat into the dadoes cut into the stiles? I will have only 1/4" of material on each side of the tongue.

Re: Warped!!! - JimReed@Tallahassee - 05-28-2016

Sorry to hear about your problem but it seems solvable. Pictures would help but I am guessing that you are doing traditional rail and stile panels. That means a groove (not a dado) and a tongue (rabbet in your case). Traditional methods have this assembled with the panel floating so it can move. In this case, your panels have warped, so they have shown their tendency for movement. I do panels like this all the time and they work well.

When I make the panels, I use a plane to bevel the back instead of cutting a rabbet. I think it makes the wood stronger and less apt to split when moving. I also like to leave generous wood on each side to allow for movement. Repairing antique furniture made me cuss when the panels shrunk enough to leave gaps. So I always wanted mine to be generous. I would feel better with 3/8 on each side instead of 1/4, but you will have to go with what you have unless you want to glue up some thin strips on your lateral edges as insurance. You can make the side grooves a little deeper to accommodate. (It sure would be nice to have a Rumbold plane with a 1/4 grooving blade for this.)

Anyway, a slight warp in a 3/4 panel would not bother me too much. Just take it easy and make sure the panel will float a bit. A little wax might help during final assembly. Good luck.

Re: Warped!!! - cputnam - 05-28-2016

Don't know if oak behaves as in this scenario. I left my 1st panel on the bench and it promptly warped (differential air flows.) I flipped it the other way and the warping eased off some after the same amount of time.

Re: Warped!!! - tim_leo - 05-28-2016

I wonder if they warped because they were clamped to the bench and only received air flow on the top surface? What about leaving them air dry on both faces for a while? They may flatten out with a little time. Maybe clamp them flat with cauls so they get more air flow on the wet side?

Re: Warped!!! - Wilbur Pan - 05-28-2016

joemac said:

From fear of warpage, I clamped them flat on my bench. You guessed it, they both warped. The panels are 18" wide. If I hold one edge on the bench, there is a 3/4" gap under the opposite edge. Since they are to actual size, I can't cut them and reglue.

Hi Joe,

Some thoughts:

The warpage issue depends on how the boards warped. If your panel is warped symmetrically, then your 3/4” gap is really just a 3/8” deviation from center, and you probably don’t have as much of an issue as you think you do. On the other hand, if the board is mainly flat, and curls up 3/4” over, say, the last 20% of its width, then you have a bigger problem.

The suggestions above for flipping the boards and seeing if they equilibrate are good ones. Clamping the board flat to the top of your bench is basically asking for unequal moisture loss. Next time, just sticker the pieces prior to final dimensioning. If you really feel the need to weight down the boards, add some stickers to the top and put the weight on those stickers, so you still get airflow around the boards.

My take is that the problem isn’t flattening the boards so you can get it into your rail and stile frame. The problem is going to be what happens after you get it all assembled. The rails and stile need to be constructed well enough to prevent the warped panel from pulling the rails and stiles out of flat. I like Jim Reed’s suggestion of beveling the sides of the panels to get them to fit in the grooves. You also may want to thin the panels a bit more. This will help prevent any post assembly warpage issues, since a 5/8” thick panel that’s warped will put less pressure on the rails and stiles than a 3/4” thick panel that’s warped to the same degree.

Finally, next time you do this, you might want to make your panel glue up oversize and let it stabilize before cutting the panel to final size. DAMHIKT.

Re: Warped!!! - acanthuscarver - 05-28-2016


The most concerning part of your story is, you're using quartersawn material. Under normal circumstances that should have all but eliminated warping. The fact that you say you resawed it gives us the first clue as to what's happening – moisture imbalance. White oak is a fairly dense wood and resawing 8/4 means the fresh faces definitely have a higher moisture content than the ones that were the outside faces of the original board. When you clamped the panels to the bench, you caused more imbalance.

Probably the best course of action at this point is to put some stickers on the bench, then a panel, more stickers (lined up with the ones below), the other panel, another layer of stickers, a piece of plywood or other panel of roughly the same size, then some weight (a few cinder blocks or something heavy). Let the whole pile sit for a week (more if possible), disassemble and see if the warp has diminished. If it has, glue up the doors and proceed as planned, but make sure to keep even airflow around the doors once assembled. If not completely flat, reassemble the stickered pile and let it sit a while longer. If the panels get back to flat, you shouldn't have a problem with continued warping because the quartersawn material should have reached equilibrium.

Hope that helps and that your panels go back to flat.

Re: Warped!!! - Paul K. Murphy - 05-29-2016

The letter C
The letter S
Two different things.

When you view your panels straight on from the end, they are shaped like the letter C, correct?
Since you have book matched, we can assume that one side of the panel is what was inside the plank, and the other side is what was outside the plank. If, for example, the tendency of the wood was to curve in C-like fashion toward (or away) from the center of the plank as a result of resawing, the panel would be C-shaped. A C-shaped panel indicates dimensional change attributable to resawing.
On the other hand...
Imagine your plank before resawing. Arbitrarily name one face A and the other face B. Assume for the purpose of discussion, the natural tendency is for the boards to curve toward A and away from B. Your book match would result in an S-shape.
I'm guessing it's C-shaped. Resawing lumber undergoing dimensional change attributable to the resawing. Lumber like that ought to be in stick for a while before working on it.
Why do you say quartersawn? You didn't specifically say the plank you resawed was quartersawn, did you? A curved shape is an unusual shape for any quartersawn plank to assume. On a quartersawn plank (your panel) the tree rings should look like this when the panel is laid flat: |||||||||
If you are quartersawn wood, that is what your anatomy looks like. You really don't have it in you to do curves. Your anatomy doesn't help you to form a curve, even when the prettiest girl board says she'll be your girlfriend if you'll curve for her. You're Mr. Straight up and down lines of grain.

Re: Warped!!! - joemac - 05-29-2016

They are in the shape of a "C". I think that I will take Chuck's suggestion and sticker them and then re-clamp for a week or so. I was not thinking when I clamped them to the bench. Obviously they could acquire moisture from only one side and therefore would warp.

The plans calls for a 3/4" thick panel, but going down to 5/8" won't be a game changer and might allow me some wiggle room to plane off some of the warpage.

Thanks for all of the great ideas.

Re: Warped!!! - acanthuscarver - 05-29-2016


Don't clamp the boards down. Just adding weight to the top of the pile allows the boards some wiggle room. If you clamp, you may end up holding the boards fast which could lead to cracking. You want the fibers to gently relax back to that flat state.

The idea idea of adding weight is to give the pile a little extra nudge. I'm talking 25 - 50 lbs. It'll help push the boards back toward flat (it's that gravity thing) better than if you just stickered the pile and walked away.

Good luck.

Re: Warped!!! - Paul K. Murphy - 05-29-2016

I'm still wondering what you see when you look at the growth rings on the end of the panel.
If it is quartersawn, you see this: