Help with removing bow

[bsheeres]

I have a piece of slightly figured maple measuring 23 x 6 x 3/4 that I wetted and planed last night. However it appears to have dried with a slight (somewhere between 1/32 and 1/64) bow in it (maybe it wasn't planed completely flat either, but it sure looked that way last night). I'd really like it to lay flat w/o going through the whole process again; there is some thickness to spare but I don't want to risk it bowing again/more. Is it realistic to think that if 1/8 shims were placed under the outsides of the board then weighted for a few days that the bow could be negated?

Thanks

Brian Sheeres

[Swingman]

The answer could depend entirely upon what you're using it for?

[DonkeyHody]

If it was only last night that the piece was wet, wait a few days before you do anything else to it. The moisture content needs to equalize throughout the board, and that takes time. If it was straight before wetting, it should return to that condition when it has thoroughly dried and equalized.

Why'd you wet it?

DonkeyHody "Every man is my superior in that I can learn from him." - Thomas Carlyle

[mike hide]

I do not think that will work . Each time you mess with the surface you rearrange the internal stresses in the wood because the stresses at the free surfaces is zero, and by planing it you have created a new free surface . It might take several days for the stresses to completely relieve themselves . each time now you repeat the process the movement should be less

[bsheeres]

chessboard surface and i'm really gunning for FLAT

[bsheeres]

It's figured wood and my straight knife jointer and planer were creating considerable tear-out on the dry wood dispite taking even the thinnest passes. I read a few posts on this NG about wetting the board to soften the grain. It worked really well too; zero tear-out and only a little, what I guess you'd call, scuffing of the grain, nothing a scraper can't fix.

Thanks.

[bsheeres]

Thanks Mike,

I'll wait a few days then repeat the process. The board started with some twist and 1/4 was milled off, so I'm sure the stresses changed quite a bit. Second time around only a small amout should have to come off. I'll keep ya posted.

[DonkeyHody]

Well, now I've learned something, which I'm still not too old to do. It all makes perfect sense, I just wouldn't have thought of it. I'm so anal about rust that it wouldn't have occurred to me to put wet wood through my jointer or planer. But I can see where I could take precautions to prevent any rust damage and get better results on my wood in some cases.

DonkeyHody "Every man is my superior in that I can learn from him." - Thomas Carlyle

[Teamcasa]

Re-saw it to 1/4" book match it then laminate it to a strong substrate. Dave

[TWS]

When wetting a board to reduce tearouts you only need to spray the surface. I use a mixture of water and rubbing alcohol based on a recommendation from someone on the wreck. I keep a spray bottle near my planer and only have to spray every other pass to keep tearouts to zero. Spray on, wait a few seconds until the wood wets and then wipe off the excess - it isn't enough to warp a 3/4 inch board (1/4 inch maybe but then I spray both sides to keep things in balance).

TWS

[bsheeres]

Thanks. That's nice to know. I wasn't sure how much water to use. I'll try less (and the alcohol mixture) when I run them through again in a few days.

[Dave W]

Did you wet and plane both sides? If not there is your problem. In my experience, using weights to remove bow is a waste of time. Dave

[bf]

I agree on waiting a couple days to see what happens. Is there anyway you could borrow a drum sander? It would flatten it without tearout or wetting. Might be the excuse you're looking for to buy a drum sander.

[bsheeres]

I did wet and plan both sides. Interesting though, I never stopped to consider how wetting/planing just one side might effect the wood.

Good to know I shouldn't waste my time with weights.

[Sam]

If you let it sit flat on the workbench overnight one side might have dried out more than the other (or one side absorbed more from humidity). Turn it over and let it sit overnight and see what happens. If it's bowed from moisture, the concave side is drier than the convex side. Sam