Question about Preventing Wood Movement

[Glen Blanchard]

Let's say you mill a board and let it sit for a week or so prior to working this board any further. Let's also say that somehow you KNOW (perhaps through divine intervention) that this board will cup or warp if left flat on the benchtop - so you sticker it and allow for proper air circulation around the board. When you return, the board is just as flat as when you finished milling. Great job!!!

Now I have heard of some folks clamping a board to the bench top to prevent movement. What would happen to this same board after the clamps were removed if it was clamped rather than stickered?

[Dan Barr]

if the board is going to cup, it will cup. clamping is just preventing that one side from getting air and therefore potentially creating a larger difference in tensions on the two sides.

Also, it goes to question: how would you know which side will cup before you clamp it? this is impossible. just because one side gets more or less air, does not necessarily mean that one side or the other will cup.

i dont believe you can ever really "prevent" wood movement. your either compensating for it, retarding it or fighting in vain.

that being said, i like white oak.

ciao,

dan

[Jim Becker]

Well, firstly, you cannot "stop" wood movement. Wood moves. Period.

But the sticker method is superior because it allows moisture access to/from both sides of the board. If you clamp it fast to your bench, you could actually set up an unequal moisture content situation...and a board that cups. What I would do is mill it "close", but not all the way. Sticker it until it's time to use and then do the final milling (both sides!) just prior to doing the joinery. Of course, in reality, I mill it up and use it right away in many cases...shop time is short... ;)

[Gary Herrmann]

Glen, I've got a big ol project that is taking me forever because of my tendon surgery. So I'm going slow even when I do feel like pushing 8" wide 8/4 cherry across the jointer.

I'm milling them overthick as a first pass. Why?

1. This is a huge project (for me) - a loft bed with built ins for my son's room
2. The wood was pretty twisty
3. I'm going slow because I'm still kinda dinged up - so some of this stuff was milled before my surgery - 3 months ago

So I figure I'll "rough mill" all my stock then mill it to final dimension as I'm ready to assemble the components.

So mill it somewhat oversize then final mill it within a day or so of assembly or joinery and you'll have fewer movement problems.

[glenn bradley]

I have stickered boards and then clamped them. In the end, they did whatever they were going to do anyway. I'm much happier now that I've learned to accept the material for what it is; I used to try to force it to my will. . . never worked out too well.