Help me understand

[collinb]

I picked up a piece of hard maple at WoodWerks the other day. Sat in the garage a couple of days before getting to it this evening. The change in humidity had added a bit of a bow at one point but not so much I couldn't work with it.

Before I took it home they offered to straighten one edge for me. They've got this neat saw with a laser guide and guide lugs at feed end. Just align the board to the laser and feed it in.along the lugs and it cuts a nice straight edge. No futzing with a fence or jointer.

So I take this board and attempt to cut 2 inches off that straight side. And what happens? The piece I cut off ends up with a bow in it!

Tale saw heel adjustment, perhaps?

[Chestnut]

Internal stress in the board it warped once and it warped again.

[Coop]

Yep! Life sucks when that happens. Now you have a winding stick. 

[pkinneb]

What they said  

[Tom King]

Probably kiln dried too fast.

[Chet]

It is a real possibility with any piece of wood when you put it to you saw.  You never know what energy you might be releasing.

[mat60]

Reminds me of working with Birch.

[wdwerker]

Son of a....

[RichardA]

11 minutes ago, wdwerker said:

Son of a....

Beech.......... Right?

[wdwerker]

Beech/Birch ...both work.

[wdwerker]

Long gradual slow drying reduces problems like your warped board. So Tom probably has it right.

[Coop]

Damned surprised  that you didn’t have a problem at the ts while ripping. 

[Isaac]

A straight line rip saw is cool, but watch out, once it goes, there is no turning back. If the operator isn't careful, you can lose a lot of material in the process, 

[..Kev]

This is why, when you can, you cut things over sized and let them sit for a couple days before final milling.  This is also why those first rips should be on the bandsaw so you don't catch a kick back in the chops..

[curlyoak]

I cut to length the least I will need. If I needed several 2" wide pieces 18" long I will not make long rippings then cut to length. Plywood is OK. With solid wood I recently needed 7' rips 2 1/4" wide. The first rip is around 2 5/8". So I could re-true it. 1 or 2 rips won't pass grade. Sometimes it comes off perfect to warp. Not too often. It has to do with grain tensions. The center of the tree is much different than near the sap wood. Sometimes it appears to give a clue and sometimes false clues. Hard to figure. Part of the waste factor and hard to calculate.

[collinb]

I've been cutting for 25% waste and that seems to cover most cases. It seems some pieces of wood just don't want to cooperate. :-(

This one stood out as such a problem I thought showing it might provide some insight.

10 hours ago, mat60 said:

Reminds me of working with Birch.

It's hard maple.

9 hours ago, K Cooper said:

Damned surprised  that you didn’t have a problem at the ts while ripping. 

It did get stiff.

I think with the old Craftsman table saw I had, without a riving knife, it *would* have been a problem.

**

I took what was left for a second rip but this time went to the bandsaw. Guess what? No bend!

It could be that the wood changed in those two extra inches. Or it could be something else. That's why I'm going to check the heel adjustment this evening.

[Tom King]

Everyone knows how bad Yellow Pine is for this.  Before 1992, when the last local sawmill went out of business here, I could buy Yellow Pine in any dimension, and expect 99% of it to come off the saw with no stress.  Back then, they would saw it, air dry it on sticks for a year, and only after that, kiln dry it very slowly using sawdust as the kiln fuel, and finish plane it.  You could buy a whole stack of 2x4's, without looking at them, and expect the majority to be perfectly straight.

These days, they saw it, kiln dry it in 24 hours, dress it fast, and band the bundle.  You need to stand back when the straps are cut.

I had one old carpenter, L.W. (Jack) Jordan,  working for me that quit after that mill closed in 1992.   We'd build a wall one week, and the next week we'd have to fix it.  He spent the rest of his life building cabinets in the shop in his back yard.  He put his tools back in his truck that day, shook my hand, and said he was through building houses because of this #$%%^&* lumber.

[Midlife]

What you need is a sliding table saw, no fence to jamb against . 

Fingers away and your standing to the side away from kicked back timber .

[collinb]

7 hours ago, Midlife said:

What you need is a sliding table saw, no fence to jamb against . 

Fingers away and your standing to the side away from kicked back timber .

Last year I did something similar (and crudely) and subsequently abandoned it, though may have to resurrect it in a proper fashion.

That is, a 6' long board with a 3/4" track for the miter slot.

I could go with  12" W x 6' L to get most all jobs done.

**

Back to the op: I think the fence position may be the big issue. I cut another strip off using the bandsaw and there were no issues with bending.

[pkinneb]

1 hour ago, collinb said:

Back to the op: I think the fence position may be the big issue. I cut another strip off using the bandsaw and there were no issues with bending.

The bandsaw didn't have issues because the bandsaw blade flex's the TS blade does not. That board would go all wonky regardless of what tool was used to cut it due to internal stress.

[pkinneb]

Here is a quick informative video on wood stress posted by a local wood supplier

 

[Chet]

Very interesting

[sheperd80]

This is why i dont use hard maple for cabinet doors anymore. All wood does it but hard maple is the worst in my experience

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[dust factory]

Rip it down the middle, turn one piece over and laminate together, I tend to not use anything wider than 4 inches without lamination to prevent cupping.