Warping What did I do wrong?

[Craig Hunt]

I'm fairly new to woodworkking been doing this for about three years.
I Have been building skills, right now I have been planing down boards by hand.
A couple of weeks ago I started planing some poplar down to reduce the thickness from about 3/4" to 5/8".
After letting the board sit in my garage for at least a week.
I haven't bee able to get into the garage till today and I noticed all of the boards I have been planing are
very badly cupped. Weather wise we have gone from very mild winter to dry mid 80's weather here in a weeks time.
Very strange weather for this time of year around here. Then Yesterday it rained several inches. My goal is to get the stock down to 1/2" thick but I don't know if my boards can be flattened any more. I had most of the wood for my project dimensioned to final size.
Is there anything I can do to these boards to get them flat. What could i have done to prevent this mess?

Thanks
Craig

[David Nelson1]

Square/clean up an edge. Mark the edge so you can take the dimension from the middle of the board. Flatten one side to get your reference, flip it over and plane till you hit the mark. Then flip it back and repeat the process. Stack it so it can dry on both sides for a few days. It helps if you kinda know the moisture content of the wood to start with. No guarantees wood will move.

I don't plane for dimension much by hand, but the same rules apply to machine use. Since I learned and try to pay attention things have been much better. Still get a surprise ever now and again.

Just thought of another trick. Don't take it to final dimension all at once, sneak up on it so the majority of the wood can equalize to the new size.

[Neil Brooks]

When you plane, or rough mill your boards, you often expose inside wood that isn't as dry as the outside wood was, making it susceptible to warp.

After milling, it's not a bad idea to stack and sticker them, and ... put some weight on the very top boards, directly above the stickers.

If you don't know ... stickers are (roughly) 3/4" x 3/4" x whatever length pieces of wood.

Here's a picture of stickered and stacked lumber:

http://extension.missouri.edu/explore/images/g05550art01.jpg

You want them off the ground, and room for air to circulate on all four sides of each board.

http://www.twistedoaksawmill.com/Services/stack.gif

A bit of weight on the top helps to keep them flat as they dry.

[Chris Tsutsui]

If you planed only one side of the board then that could cause the wood to warp. As mentioned before, plane both sides equally to close to the final dimension. Then allow both sides to air dry at least 24hr before final dimensioning the board prior to assembly.

As for a fix, I heard somebody putting a board over a moist lawn on a warm day so the moisture from the lawn side is on one side and the sun is on the other side and this will hopefully warp the board back. Never tried it though... What I do with warped boards is i cut them into shorts and replane them flat, let dry, etc and use them for something else.

[frank shic]

craig, don't feel bad. all of us have had wood that's warped on us. most of the times, though, it's not critical that the wood actually be a specific dimension. i have yet to see my wife whip out a ruler and measure any of the things i've built! are you using these pieces for drawers? because the drawers themselves won't care if they're precisely 1/2" thick ;) are you using a jointer to flatten a face before thickness planing?

[Scott T Smith]

If you planed only one side of the board then that could cause the wood to warp. As mentioned before, plane both sides equally to close to the final dimension. Then allow both sides to air dry at least 24hr before final dimensioning the board prior to assembly.

.

Chris and David are correct, most likely your problem was caused by taking off more material from one side of the board than the other.

[Gary Kman]

I didn't see how wide they were. If they were 4" you have had tough luck, if 16", it's no surprise. If the boards were dried without internal stresses they are apt to return to flat as soon as the moisture content of the two sides equalizes.

[Prashun Patel]

You also didn't mention how it was stored in the garage. Hope it wasn't directly on the floor.