Bad wood? Bad technique? Bad luck?

[William Lessenberry]

Started a project that requires 3 pieces each of maple, walnut, cherry, and padauk, 1/2" x 5" x 14". Used kiln dried boards ~4 foot long, 5/4 maple, 4/4 walnut, cherry, and padauk. I resawed the lumber to 9/16"~5/8". All of it except the cherry came out flat enough to crosscut and plane to size. The cherry warped and cupped to the point of being unusable. Got another piece of 4/4 cherry from a different supplier and crosscut the pieces to approximate length before resawing instead of running the full length of the piece like I did the first time. Worse result with same cupping and even a little twist thrown in for good measure.
Is this happening 'cause of something I'm doing, or is the God of Cherry just messing with me? I really don't want to joint 1/2" off of these boards, but if y'all think that's my only option I'll try it.
Thanks for your help.
BillL

[Prashun Patel]

Resawing can release tension that can cause cupping. Improper drying can cause this too. The grain orientation will also play a role.

Can you show pictures? It's not specific to cherry. Although I will say that in the North East, where cherry is common, I'm more likely to find DIY cherry lumber, which I can't always be sure has been dried properly.

[Ron Citerone]

I have really started using acclimated wood that is stored in my attached garage. Much less movement issues. Especially for resawing, I am a strong believer in acclimation. With door stuff I joint both sides lightly and then let it sit a few days before final milling. Some boards just don’t like being resawn.

[Jimmy Harris]

Some boards will do that. If you get good at reading grain, you can often avoid that (to some extent) at the sawmill by selecting boards with straighter grain that will likely contain less internal stresses. But it's not always possible to see that ahead of time, and sometimes you don't have much of a choice, due to limited selection. I have, on many occasions, dealt with boards that were straight, but had so much internal stress that when I ripped them, they fractured during the cut due to the uneven release of those stresses (since you can't cut through the whole board at once). I even had one recently explode on me on the table saw, which was a scary experience.

Outside of getting good at reading grain and avoiding potentially problematic wood, there's not much you can do. Well, you can also buy wood that's thicker than you need, cut it to rough dimensions and let it warp, and then joint and plane it straight. But that doesn't always work either. I've had flatish boards warp due to planing them, which removed just enough wood and exposed an imbalance of the internal stresses, causing a flatish board to warp further while trying to flatten it. Wood is sometimes a balancing act.

Though often times it doesn't matter much if the wood warps a little, as the design of whatever I'm building will straighten it out. And sometimes I can hide the warped board in a way that no one will notice in the final piece.

[Mark Hennebury]

First requirement to successfully work with wood is to have a basic understanding of the nature of the material.
Spend a day in the shop with one of these books and a variety of wood species and explore and experiment.

The knowledge that you acquire will guide your work for the rest of your life.

Cut & Dried: A Woodworker's Guide to Timber Technology by Richard Jones.

Understanding Wood: A Craftsman's Guide to Wood Technology by R. Bruce Hoadley

[John TenEyck]

Kiln dried doesn't mean much if it's not close to equilibrium with your shop. KD lumber typically is 6 - 8% average coming out of the kiln, but I imagine the equivalent RH where you are might be much higher than 35 to 45%. That sets up a large differential in MC across the thickness of the wood, which slowly equilibrates given enough time to some new value after which it can be resawn with little problem. On the other hand, if that lumber had been in your shop for weeks/months prior to using it, then you just got some bad wood, which might have been due to improper drying or cantankerous Mother Nature.

John

[John Kananis]

Maybe it's just me but I find that fruit-wood in general prefers to be sawn in thirds instead of halves. If I absolutely need two pieces from one board of cherry, plum, etc, I will first joint and plane flat, then immediately resaw and stack. Again, could just be my perception on fruit-woods but I don't think so.

[Richard Coers]

This article pretty much covers all that can be wrong with log which will give you unstable lumber. https://www.woodworkingnetwork.com/b...g-wood-defects

[Edward Weber]

Maybe it's just me but I find that fruit-wood in general prefers to be sawn in thirds instead of halves. If I absolutely need two pieces from one board of cherry, plum, etc, I will first joint and plane flat, then immediately resaw and stack. Again, could just be my perception on fruit-woods but I don't think so.

This is my experience as well, Fruit-woods are notorious for moving in all manner of ways.
Pictures might help to know if there were any visual indication of potential movement but it's not always clear.

[Steve Demuth]

This is my experience as well, Fruit-woods are notorious for moving in all manner of ways.
Pictures might help to know if there were any visual indication of potential movement but it's not always clear.

+1 on the fruitwood. Cherry (that is, North American Black Cherry) less so than woods like apple and pear, but still crankier than most forest hardwoods. I avoid flat sawn cherry, except for relatively narrow uses for this reason. Unfortunately, where I live, QS cherry is very hard to come by.

[Steve Demuth]

It would be helpful to see pictures of the wood. Flat sawn cherry can be tough to work with. You don't mention whether your shop is a fully conditioned space, but if it's not, and you're taking kiln dried (likely 6% moisture) and resawing, the wood is immediately absorbing moisture heading toward a more natural EMC of 12-14% in your area at this time of year. Even if it were perfectly dried and had no unresolved internal stresses, a resawn, flat sawn cherry board only 5/8" thick is highly likely to cup in the process. Things you can do: 1) Find quarter sawn wood to work with; 2) Fully acclimatize the wood to your local EMC and conditions before resawing. You can also try planing 1/16" off both sides over an a period of days, and it might meet acclimatization in the middle and get you what you want.

However, it's worth noting that if the piece you're building doesn't hold the wood flat by virtue of construction, and it's destined to go into a modern, air conditioned space, it might warp again as it dries back down.

[William Lessenberry]

Pictures-PICT0446.jpgPICT0447.jpgPICT0448.jpgPICT0449.jpgPICT0450.jpgPICT0451.jpgPICT0452.jpg

[Richard Coers]

I sure can't figure out the problem looking at those photos.

[William Lessenberry]

First pic is the board sections in the order they were before crosscutting. The next three are the individual boards so you can see grain on the top. Next three are back lighted end shots showing the extent of the cupping/warping of the boards.
I'm going to the wood store tomorrow and see if they have some 5/4 material and try that.
The wood was acclimated to my shop for a couple of weeks and the place I buy it is only 16 miles away in a building like my shop, so I didn't think that would be a problem.
BillL

[Steve Demuth]

I think the pictures tell the story. ON the first end grain pic, you've got a piece flat sawn from near the pith of the tree, with grain running from zero degrees to the width, up to 45 degrees. If there is any moisture change after the cut, it's going to generate differential forces that a 1/2" board will not be able to resist. If you have to have thin cherry for your project, I'd recommend you look hard for some with QS grain. (Because I have a hard time finding true QS cherry, I've been known to take wide flat sawn boards from the center of a tree, cut the center out and glue them back together to get wide enough QS grain. You really can't tell the difference if you take a little care with the cut and the grain is truly vertical).