Removing Warp in NEW Cutting Board - How?

[Patrick Irish]

This board was flat after going through the drum sander. I got it wet a little to raise the grain and sand it. Brought it inside and referenced it off the granite counter and it wobbled just a little. I wiped both sides with a wet rag then placed a bunch of heavy stuff on it with the bow face up. A day later I take the weight off and it's flat and perfect.

Well......hours later I walk by the board and turn it over and the bow is back. Used a feeler gauge and it's about 5/64" gap in the middle.

How can get this bow out? I really don't want pass it through the drum sander on 60 grit for like 30 minutes. It would make the board too thin. It's already about 1".

I was thinking about soaking it mineral oil for a certain amount of time then using cauls and clamps and crank it down. Let it set for a few days and unclamp. As long as it stays oiled and doesnt dry out, should stay flat.

I read soaking in water works but the board has to be 100% dry before the clamps are taken off. That would take a few days.

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[Michelle Rich]

since you have wet it, and put weight on it, already and the bow has returned, I doubt you can "fix it". I think your only option is to plane/ sand it. Many folks bow their boards in the gluing/clamping because they don't keep the boards level on the clamps or put too much pressure while clamping.

[Andrew Hughes]

It will never lay flat.
Did you mix long grain with end grain? :confused: If so hang it on the wall and start over.

[Roger Bull]

Don't try to force it flat and expect it to stay that way. Let it stabilize in whatever shape it wants and then flatten that shape.

Did you overheat it in the drum sander? That will often warp them. You might try heating the convex side.

Adding feet will make any warp far less noticeable.

As Andrew said, if you mixed long grain and end grain you can expect problems in he future.

[Bernie May]

I would cut out two of those long thin boards (walnut?) running across the board so you have three pieces, assuming I have the direction of the curve correctly. I would then run each third through the drum sander and finally glue new thin boards in between the three pieces. this will reduce the thickness less than trying to do the whole board.

[andy bessette]

It will never lay flat.
Did you mix long grain with end grain? :confused: If so hang it on the wall and start over.

This. Redesign and start over.

[Doug Hepler]

Patrick,

If it was flat once, it probably can be flat again. It is warped because the moisture content on the convex side is greater than the MC on the concave side. If you are willing to put it on feet, it probably can stay flat. Before you give up, this might be worth a try: put heat on the convex side, using sunlight, a heat lamp, hair dryer. Watch it carefully and stop when it is flat. Glue and screw 1" thick strips of hardwoodwood in the appropriate direction to counter the warp. The feet might not be in accord with yur esthetic but they will hold the board off the counter so that the bottom cannot get wetter than the top.

Doug

[Matt Day]

As Andrew said, the cuttings board is doomed by design. Not an insult of course, just a lesson.

It sure looks cool though, I really like how the sap wood makes it look like it’s moving as it progresses left to right.

[Yonak Hawkins]

If you put rubber feet on one side it may dampen the rocking and keep it out of standing water on the counter top.

[Patrick Irish]

If you put rubber feet on one side it may dampen the rocking and keep it out of standing water on the counter top.

I may put rubber feet but the person I was making it for didn't want feet.

Regarding grain direction, I did an endgrain brick pattern. So after initial glue up in long grain, it's cut into strip and turned up so the end grain is facing up. I then added the strips of walnut that were about 1/8" thick. I think the walnut strips were a combo of edge and face grain. Nothing was glued to end grain.

It's been sitting under a tub of mineral oil to flatten in. I think I'm going to sand it tomorrow from 60 grit to 120, then an hour in mineral oil bath, then cauls and clamps for a 2 days. I'm hoping the mineral oil will moisten the wood and allow the clamps to and cauls to work.

I definitely think my clamping when making boards is not 100% even. Few of the end grain boards I've made I've noticed haven't been flat and needed feet. Partly do to bad belt sanding and I think some to uneven clamping with pipe clamps. I crank down too much on the outside I think.

[Dan Hahr]

You will not bend the wood into submission. Don't waste your time. Just set it on edge or on two stickers to let it dry evenly throughout. It it glued up flat it will go back to flat. Then finish it. And feet are really not an option. It has to have air circulating around it at all times.
Dan

[Brian Glendenning]

Add feet and shim one of the feet if you have to. (I drill a hole in a wood shaving, put it between the foot and the board, and cut the excess that sticks out beyond the foot with a chisel. Can't even tell it's there).