Wood Warping After Resawing

[Len Rosenberg]

I've been saving a gorgeous piece of 4/4 AAAA quilted maple to use for a foyer table top. It's been acclimating in my heated shop for 2 or 3 years. Finally built the table and started on the top.
First jointed it so it was dead flat. Resawed it down the middle, one half came out fine, the other went "sproing" and bowed over 1/8" in the middle (on a piece only 44" long).
If I joint it flat it will be too thin to use for the top.
Is there any way to prevent this? Other than buying 5/4 or 6/4 (if you can find it) and be prepared to joint it once again after resawing? I have enough of the original board left to make a second top, but expect the same problem to occur.

Thanks for any suggestions.

Len

[Jason Beam]

First and foremost: Wait.

I mean it - give it a few days and see what it does. After a week or two, I'll bet it changes - better or worse, i dunno - but the first thing is to wait it out.

Second: How thick is the piece? If it's thin and going to be captured in a frame of some kind, I wouldn't worry about it.

But in the end - wait it out, give it some time to settle - no matter what, it's likely to end up different than it is right now - which means whatever you do now may not be the best course of action. It may flatten itself back out pretty well - it may curl into a tube - chances are, it will change from what it is now, though.

[Andrew Hughes]

Len the only thing I can think of is to rip the piece down the middle,then resaw a shorter board.That will hopefully take some of the tension.Leave them long so you can match the figure back.Figuerd maple can be sometimes difficult to edge join back together,So get you plane your jointer sharp and ready to work.Dont wait after resawing to get your boards back together.

[Len Rosenberg]

Thanks Jason, I'll wait and see what happens. Although, I've never seen a piece of wood un-warp. After resawing, each piece is about 5/8" thick. Will not be in a frame, will be a solid top.

Andrew, this piece was only 7 inches wide, resawed down the middle to make two pieces, which when joined would be a book-matched 12" wide by 42" long.

Len

[Lee Schierer]

First and foremost: Wait.

I mean it - give it a few days and see what it does. After a week or two, I'll bet it changes - better or worse, i dunno - but the first thing is to wait it out.

Second: How thick is the piece? If it's thin and going to be captured in a frame of some kind, I wouldn't worry about it.

But in the end - wait it out, give it some time to settle - no matter what, it's likely to end up different than it is right now - which means whatever you do now may not be the best course of action. It may flatten itself back out pretty well - it may curl into a tube - chances are, it will change from what it is now, though.

I agree, but put both pieces on stickers and place a weight on top of them while you wait.

[Len Rosenberg]

Thanks Lee, I will try that.

Len

[Andrew Hughes]

Oh i see now, that's a bummer and tough one.Maple is such a unpredictable wood.Good luck

[Phil Thien]

Maple is one of the most reactive woods I've resawn.

I've vote for waiting, I've had pieces improve to the point of being usable.

But these days I purchase my lumber as close to final thickness as possible, or at least make sure I have enough to handle warping.

[Len Rosenberg]

Thanks Phil. I will wait to see what happens, put a 25 pound weight on the board. It barely budged.

For my second attempt with the remainder of the original board, I dropped it on the floor several times (there was a Fine Wood Working article by a guy who said that would relieve some of the internal stresses), and will use a blade with a thinner kerf to give a touch more room to joint/plane if it bows. Other than that, this is an expensive lesson....

Len

[Chris Padilla]

Wood: a fickle medium!

You can wait and hope for the best but I doubt it'll get better seeing how it has dried for a few years. You simply released internal tension...it happens.

I've never heard of the drop method to release internal stress. It makes zero sense to me that it would work. The internal stresses are built into the fibers of the wood as it was growing or perhaps as it was dried or both. No amount of banging it going to change that. Cutting through it, you betcha. Imagine the wood is built of several thin wires under tension and you cut through them...bang...tension released.

Anyway, one method I've used (on a much shorter board) was to soak it in water (I used a wallpaper 'tub'...fit perfect) for a couple of days and then bring it out and clamp it to oppose the bend. Don't clamp it flat...you have to clamp it slightly over-bending it the opposite way. Ignore it for several days and see what you get. Maybe I was lucky...I unbowed a piece of maple this way.

images.jpg

And just to be clear, it did 'bow' as show in the above pic, right? I want to make sure it didn't cup on you.

[Len Rosenberg]

Thanks Chris. I'm skeptical about the drop method but nothing to lose. And yes, it did bow. Meanwhile, anyone know of a good source for 6/4 premium quilted maple?

Len

[Peter Quinn]

It happens. 4/4 is pretty thin to split for a top, I'd generally start with thicker stock if possible. I'd be very surprised if it flattened itself at this point. If the moisture content were different between core and surface perhaps it might equalize and move towards flat...I wouldn't count on it. A this point I'd consider ripping the cupped piece down the middle or along the apex of the cup on the bandsaw to minimize the kerf, joint and reglue. This wont make it flat but it may lessen the severity of the problem to the point the wood is again usable, and with minimal visual impact. Then you can glue the two halfs and pull it down when attaching the top to the table.

[Phil Thien]

Anyway, one method I've used (on a much shorter board) was to soak it in water (I used a wallpaper 'tub'...fit perfect) for a couple of days and then bring it out and clamp it to oppose the bend. Don't clamp it flat...you have to clamp it slightly over-bending it the opposite way. Ignore it for several days and see what you get. Maybe I was lucky...I unbowed a piece of maple this way.

I did this once with some zebrawood, both halves bowed pretty bad. I applied water (via spray bottle) to one side only (the side that needed to be longer). I did this repeatedly, maybe a couple of dozen times over a two week period. I got them pretty flat and thought for sure I had just added too much water but I let them sit for a year and in the end I'd say I reduced the bow by 75%.

Doesn't help if you need the wood immediately but I was able to use the wood for a different project.

[Matt Day]

The math isn't working for me. You said you started with 4/4 and ended up with 2 - 5/8" pieces after resawing? Based on your last post I think you started with 6/4 right?

I've had similar problems with maple where it reacts to milling. Solution - buy more than you need!

[Phil Thien]

The math isn't working for me. You said you started with 4/4 and ended up with 2 - 5/8" pieces after resawing? Based on your last post I think you started with 6/4 right?

I've had similar problems with maple where it reacts to milling. Solution - buy more than you need!

This last weekend I did some resawing, a little maple, and a little walnut. The maple bowed (I still was able to get the 1/2" I needed, it was oversized enough to allow for some bow).

The walnut was really perfectly straight.

Why is maple so prone to this?