Question about Woods that have warped

[stevenson kam]

i saw an online store that sells turning squares that have warped, i'm planning to order but i need stable woods.

i want to know if it's possible for a warped wood to warp again?
if yes, after several times of warping, is there a chance for the wood to be stable?

i'm also wondering instead of storing the woods for months/years, why don't we do it the reverse method. once it moved, we just cut it straight or to our desired shape then turn it. just a thought... :)

all inputs will be appreciated and will help me decide if i will place the order.

[Paul Atkins]

I can't answer all your points, but here is a go.
It depends whether the stuff is dry now. If it's still wet inside and you cut/turn it it will warp or get oval to some degree. The worst warping I've had was wood with the sap left on which shrinks more than the heart. Even dry this is a gamble because there is stress between the two areas. "once it moved" to me means it is dry, so cut or turn and it should be stable. You'll need the months or years for this generally.

[Reed Gray]

Wood always moves because it is hydrotropic (absorbs water like a sponge) and is subject to absorbing or releasing moisture with humidity changes, unless it has been stabilized, which is done by infusing a polymer solution into the wood. This is why if you make a solid wood table top, you don't screw it down tight as it will push/pull itself apart. There is wet wood which is fresh from the tree 60% moisture content. There is wood which is at equilibrium, which means it is as dry as it gets when stacked outside, usually 12 to 15%. Then there is dry wood which is dried to inside humidity usually 6 to 8%. Wood that is thicker than about 2 inches can be 12% on the outside, but 20% or more on the inside, no matter now long it has been drying. If the blanks are looking warped, that is because they have lost moisture while they have been stored, but are probably still drying/moving. Any bowl blank will move as you turn it. You are removing mass, and the wood that is left will adjust a bit. Some woods more, some less. Of course, the wetter the wood is, the more it will move. If the wood is pretty dry, movement is minimal. If it is wet, it can move a lot (14 by 6 inch bowl can finish moving at 14 long by 9 inches wide, with height variation of 2 or more inches). You can rough turn, and let the bowl adjust, using the 10% rule which is a 10 inch diameter bowl should be left 1 inch thick. You need to seal, or at least bag the bowl for a month or so. If the wood is pretty dry, then you don't need to leave it as thick, but still bag it, and wait a few days before returning. My prefered method is to turn to final thickness, then let it dry and warp, then sand and finish.

Obviously, there are a lot of options, and you have to experiment to find out what works best for you.

robo hippy

[Scott Conners]

Stevenson - what do you plan to do with the wood? The answer to that question will help determine how dry you need your wood to start. I'd suggest searching this forum for information on the denatured alcohol drying process, which can reduce drying time to weeks or months instead of years. Try searching for "DNA Drying" and "DNA Method." You might also look into the boiling method, which is said to release much of the internal stresses in the wood and help prevent movement.

[robert hainstock]

I have had furniture wood warp after forty or more years. I have had it crack after as many. Dry it as good as you can, and then seal it as good as you can. Reed has given you good advice. Good luck! :)
Bob