Wood Movement

[Jeff]

Just saw this timely article about wood movement. It's instructive. :thumbs_up

http://thewoodwhisperer.com/do-they-know-about-shrinkage/

An interesting follow-up to a recent thread: "Table Top Movement".

 

[scsmith42]

Good article. The only thing that I would add is that the amount of movement is not only related to changes in relative humidity, it is also related to the grain pattern of the wood.

Flatsawn boards expand/contract the most across the width of the board; vertically grained (quartersawn) boards expand/contract about 40% less than FS.

 

[Ivey]

That was a good read Jeff, good info. thanks!

What Scott said!

 

[CrealBilly]

Good Read Jeff - thanks for posting

I agree with Scott Smith - One needs to consider the "cut" of wood and how it will be used. Perfect example: FredP and I (mostly Fred) made my wife some kitchen cabinets - she insisted on flat panel doors on the base cabinets. Fred and I glued up 2 1/2 wide strips of quarter sawn for the 20" wide doors and I have yet to see a door wrap . As a matter of fact they are still as flat as when the came off the drum sander. I expected that they would shrink in width, which they did (a little bit), but that's ok because we put a rabbit on the back side of the doors. Now if we would have used flat sawn lumber instead of quarter sawn for those flat panel doors - I'm sure we all know what would have happened - warp city and big problems.

So like Scott said - the cut of wood needs to be taken into consideration. I myself have recently decided I will not use flat sawn where movement may cause issues only because flat sawn lumber movement is just too unpredictable for me, it's grain pattern is all over the board (literally), how can anyone get a handle on how a given flat sawn board let alone a glued up panel of flat sawn boards is going to move?

 

[Jeff]

Don't despair and throw all of your flat sawn lumber in the wood burner. Yikes! I just torched a bunch of book marked panels. :BangHead:

Christian Becksvoort offers a very informative piece about how to calculate and allow for this seasonal movement all over the US whether it's built in the summer or winter and whether the piece eventually resides in Arizona or Maine.

http://www.finewoodworking.com/SkillsAndTechniques/SkillsAndTechniquesPDF.aspx?id=27129

If we understand the concept and know how to apply it to our projects then we should have no surprise long after. :eusa_thin