Does pearwood move a lot?

[Aram]

I bought some beautiful, air-dried 6/4 pearwood from Gilmer. Nice color, great curl. I'll probably make a box or two and I'm trying to decide how close to final thickness I can resaw it.

I've used applewood before, and it moved all over the place. Should I expect the same from pear?

Thanks!

[ianab]

Most "fruitwoods" have fairly high shrinkage rates, so tend to move a bit as they dry. Let it acclimate for a while to your local moisture level, as it changes in moisture that cause most movement. Internal tension can make stuff move, especially when resawing, but thats hard to predict and avoid.

[Aram]

Most "fruitwoods" have fairly high shrinkage rates, so tend to move a bit as they dry. Let it acclimate for a while to your local moisture level, as it changes in moisture that cause most movement.  Internal tension can make stuff move, especially when resawing, but thats hard to predict and avoid.

Thanks.

The good news is, it was shipped from Portland OR to Eugene OR, so the difference should be minimal!

[jteneyck]

Thanks.

The good news is, it was shipped from Portland OR to Eugene OR, so the difference should be minimal!

I found this at Craftsy.com:

With shrinkage values listed as 3.9% radial, and 11.3% tangential, volumetric change is not bad, but the 2.9 T/R ratio sounds like cupping would be a problem. In practice, however, I’m usually working with quartered or rift boards and cupping is not problematic.

John  

[ianab]

3.9% radial, and 11.3% tangential

Yup, that big shrinkage difference in the 2 dimensions is what makes it "unstable". As the grain changes across a plank or around a knot, the wood shrinks a lot more in one place / direction than another. Can cause cupping, twisting, bowing etc as the piece dries out.

But if the piece you have has "air dried" and is still reasonably straight, and isn't subject to large moisture changes, then you should be OK.

[jteneyck]

Yup, that big shrinkage difference in the 2 dimensions is what makes it "unstable". As the grain changes across a plank or around a knot, the wood shrinks a lot more in one place / direction than another. Can cause cupping, twisting, bowing etc as the piece dries out.

But if the piece you have has "air dried" and is still reasonably straight, and isn't subject to large moisture changes, then you should be OK.

Krenov loved pear wood.  Most of his stuff had members with pretty small cross sections, although I think I remember seeing some frame and panel doors he made with pear wood, too.  So it must be reasonably stable once dry, although I think I would want to limit my use of it to rift or QS. 

John

[ianab]

Krenov loved pear wood.  Most of his stuff had members with pretty small cross sections, although I think I remember seeing some frame and panel doors he made with pear wood, too.  So it must be reasonably stable once dry, although I think I would want to limit my use of it to rift or QS. 

John

I bet Kernov could be pretty picky about the pieces of wood he chose too. Straighter grain that had dried straight, then it should stay that way.  Probably able to sort out the worst behaving pieces as the wood dried.

[alnandy]

I bet Kernov could be pretty picky about the pieces of wood he chose too. Straighter grain that had dried straight, then it should stay that way.  Probably able to sort out the worst behaving pieces as the wood dried.

I've used a fair amount of both pear and apple woods.  The comments about tangential to radial shrinkage are correct.   
However, there is another factor that wasn't mentioned:  Pear trees, in general, are a lot larger than apple trees.  They also usually grow a lot taller before branching than apple trees.  I grew up in house that had 3 pear trees in the back yard; they were over 50 feet tall and didn't branch until they were over 8 ft. tall (I know, we wanted to climb them as kids but couldn't jump to the first branch!).   These trees were eventually cut down, because we couldn't reach up to harvest the pears and got tired of  being "pear bombed".
In our company's lumber storage area we have pearwood planks that are 15" wide and 8' long.   When Superstorm Sandy came thru the Northeast, one of my suppliers, who also runs a tree service, cut down some Bradford Pear trees.   We milled up 6' long logs that were about 15" in diameter and sent them off to the kiln.  No problems whatsover.
Bottom line:  If your pearwood has been kiln dried and is still flat, it is very likely to stay that way.

[Aram]

I've used a fair amount of both pear and apple woods. 
....
Bottom line:  If your pearwood has been kiln dried and is still flat, it is very likely to stay that way.

Great information. Thank you.