I have a 2x10 pine board that is kiln dried/heat treated. I cut out a section to plane down to .4" and carve. I had it on hand and didn't want to go to the store for a 10" x 10" piece.

I planed partially on one side and then flipped it to plane to size on the other side. I got it to .4" and then v-carved a pocket with my cnc router. That sucker curled right up. I'm surprised by how much.

Will using hardwood solve this or will it still curl up with hardwood as well? I did want to do this in walnut for the top so, if it won't twist out of shape then I'll pick up a nice piece of figured walnut if I can find it around here.

Even if it’s is stable with regards to moisture content there could still have been internal stresses within the wood that were released after it was cut. That’s why it’s usually a good idea to overcut a piece, let it sit a bit and then do any final dimensioning.

As for will all wood do this, each piece is different. I have two slabs of oak, 4/4 thickness from different parts of same tree. While drying one stayed nice and flat, no issues. The other one has cupped like crazy. No rhyme nor reason.

A lot has to do with the wood's grain. If you have a nice even grain running through the board you will not get as much warping. If you have a flat grain, more prone to warping.

Hardwoods do seem to warp less than soft, but all woods will move at least a little bit. A really good woodworker can predict the direction and amount of warping, and take it into account when cutting.

Unfortunately, I am not one of these people.

This shows the different ways boards are cut out of the tree and how important the grain is to warping or curling as the wood dries.

http://www.core77.com/posts/24...rt-1-plainsawn-24890

Good stuff 41. Thanx.

quote:

Originally posted by architect:
... Hardwoods do seem to warp less than soft ...

That's what I assumed and was hoping it was true. I'll get a nice piece of walnut and see if it holds. That'll be an expensive mistake if I don't take my time though.

Thanks for all the responses. I'm digging into the link now.

I've been reading about roasted wood, too. I'm not sure how it mills but should be all the same. It's supposed to be lighter, harder and more stable than it's unroasted counterpart.

quote:

Originally posted by 41:
This shows the different ways boards are cut out of the tree and how important the grain is to warping or curling as the wood dries.

http://www.core77.com/posts/24...rt-1-plainsawn-24890

Yes, thank you for the link. Very interesting and educational. I read the first part and bookmarked for continuatin.

I've had some pretty good success applying heat (from a lamp) to "un-cup" some boards.


Here's someone who's using a heat gun...

quote:

Originally posted by architect:
Hardwoods do seem to warp less than soft, but all woods will move at least a little bit.

Wellll... that depends.

In general terms: Yes, but mainly because hardwoods are cut from better trees, cut better at the mills and dried better.

Most dimensional softwoods (SPF: Spruce/Pine/Fir) are not meant for fine woodworking and, yes, will split, cup, twist, curl, warp, bow, fracture, you name it, like nobody's business.

I've some 2x4 dimensional lumber I hand-picked from back before the big box stores' lumber was quite as bad as it is these days. It's been further curing in the garage for probably twenty years or so. Still straight as a, well, as a board. I regard those to be worth their weight in gold.

quote:

Originally posted by architect:
A really good woodworker can predict the direction and amount of warping, and take it into account when cutting.

"Predict" isn't quite accurate. "Guess more accurately than you or I" would be closer to the truth.

quote:

Originally posted by architect:
Unfortunately, I am not one of these people.

Nor I.

Tho I did get it right on those 2x4s

quote:

Originally posted by ShouldBFishin:
I've had some pretty good success applying heat (from a lamp) to "un-cup" some boards. ...

Well, it curled up as it was being carved so the carving is kinda messed up. I'm going to have to redo it anyway.

quote:

Originally posted by mark123:

quote:

Originally posted by ShouldBFishin:
I've had some pretty good success applying heat (from a lamp) to "un-cup" some boards. ...

Well, it curled up as it was being carved so the carving is kinda messed up. I'm going to have to redo it anyway.

Oh - That heat trick won't take care of that - LOL.

If it is going to be attached to something stiffer when it is finished you could use double sided tape or make a vacuum table to keep it stable for machining.

quote:

Originally posted by Mikito:
If it is going to be attached to something stiffer when it is finished you could use double sided tape or make a vacuum table to keep it stable for machining.

I'm currently using double sided permanent carpet tape. I went to tape after chewing through one of my metal clamps. The carbide bit didn't even slow down. Just ate right through it.

It's a lid for a gift box. It has to lay flat without any fasteners.

I got a nice chunk of poplar to try tomorrow. I'll report my findings.

 
True quartersawn is the way to go if you want stability. The wood moves along the growth rings. It's more expensive, but it just depends on what it is worth to you. Quartersawn lumber usually exhibits beautiful figures, depending on the species. You can simulate quatersawn lumber at even Home Depot, by selecting boards where the growth rings are vertical, rather than horizontal.
 

Dont know if you need something with wood grain or not. But we use basswood for carving, I have not experienced cupping with it.

Can you glue up smaller dimension wood to make the size you are after? It will have less of a chance of warping by doing this but you need to choose your pieces to make the grain look like one board.

Try the “Roasted” wood. Very impressive stability. Bought it for storm window frames. Machines beautifully, glues very well and I hear comes in different types. I have yellow pine. I would compare the roasted stuff to aluminum blocks for stability. I am familiar with machining woods, steel, aluminum, brass, bronze and some plastics. My woodworking tools can pretty easily hold .015” tolerance. This roasted stuff is good, very good. After machining I would seal it on all sides.

 
Almost all moldings have a "backout" on the back side. When you remove wood on the face to create the molding profile, the wood will move due to stresses, so the back side is hollowed out by approximately the same amount of wood. The wider the molding, the more important the backout.
 

My neighbor who works with wood remarked that the supply of wood out there anymore seems really poor and low quality.