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I am creating an entertainment center for our home that is 105" long and will have two 30"w x 60"h x 14"d book cases on top of the counter. The problem I have run into is the countertop. I used two (2) 2x10's where I took the rounded edges off and glued them up. Everything was okay at first, but as I let it sit it has twisted on me. I am guessing it was because I used cheaper fir lumber and I don't know if I got the grain directions correct, but I would like to save this piece as best I can.

My question is, should I use the damp towel method to untwist the board, or would it be faster and better to use c-channels to straighten it? Or is there a better method. I want to keep the depth it is at so I have a 1" overhang for my base cabinets.

Long glue up board twisting

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    If two people step on the ends, does that flatten it? You might be able to make it work just by screwing it down.
    – Aloysius Defenestrate
    Commented Jul 30 at 19:49
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    Another idea (that does require getting a bit more material) is to cut out the pith/center from both boards and re-glue the rest adding a few more pieces to get back your desired width. The parts you would be keeping look like they might be more stable and straight. Also, does your panel need to be this exact thickness, or can you plane it down to take out some of the twist?
    – stanch
    Commented Jul 30 at 22:07
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    Regarding grain direction, you don’t have to match it between the two boards. Just keep in mind that the plainsawn boards like the one on the right tend to cup towards the bark (which is why some people prefer to alternate the direction of rings in a wide panel — to get a wavy pattern and not a single big cup in the worst case). The boards with pith like the one on the left can be unpredictable and develop cracks (which is why some people prefer to cut the pith out). A twist this big is probably a sign you are better off with another board :)
    – stanch
    Commented Jul 30 at 22:21
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    "should I use the damp towel method to untwist the board" I think you'll see that this method is most used to uncup or unbow, not to untwist. Dampening, even selectively, would actually have limited potential for any meaningful improvement here.
    – Graphus
    Commented Jul 31 at 7:33
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    Now, with apologies, we can see you didn't prep one or both edges properly here + possibly also didn't clamp hard enough. Getting perfectly mating 105" edges is a tough job! Even some pros would struggle to get it right believe me, so don't beat yourself up about this in any way, however do know you want to work to achieve better than this A, because it helps not to introduce irregular stresses along the joint, plus B, only thin glue joints are strong. Now this said, it's possible that just the wood itself was to blame here because it's construction lumber, and because of the cathedral grain.
    – Graphus
    Commented Jul 31 at 7:40

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I'm suspicious of the "towel method" having long-term effectiveness, and C-channels require you to "fight" the very powerful forces in play within the wood. When wood wants to move, it's going to move and there's not a lot you can realistically do to force it not to. Your best bet is to make it not want to move as best you can.

You could possibly fix this by cutting up the wood you have now so that you're only using the "outside" edges of the 2x12s. This would essentially give you quarter-sawn (or rift-sawn) lumber to work with, but you'll have to pick up another 2x12 and cut it similarly to get back to the width of the original countertop.

cut to remove center (pith) in boards

By cutting out the center of each board (and the original glue line) you'll be left with four boards having nice, tight, perpendicular/diagonal grain which will greatly reduce the chances of the wood warping or twisting again.

This will help to release tensions that are now present in the lumber which are causing it to twist. One thing to be careful of here is that the tensions present in the wood now may want to grab or seize a saw blade as you cut, so be sure to account for your saw kerf closing up on the blade as you cut. You may need to wedge the kerf open or make the cut in shallow passes to get around this dangerous aspect.

A potential added "bonus" is that this may result in a much more attractive countertop as well (if it suits your taste) because the glue lines will be easier to conceal in the narrow straight grain and the "cathedral" parts of the original 2x12s won't call attention to the fact that there are two distinct boards in use.

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  • Okay, I think this might be the best way to go. I can buy 1 or more pieces if need be. But along with this method, is there anything else I would need to look out for when glueing those pieces back together? Like should I clamp the pieces tighter? Should I still use dowels to help keep things straight and in line with each other since is 8.75' long?
    – Matt L.
    Commented Aug 1 at 4:55
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    "anything else I would need to look out for" Better prep of the edges as I refer to above. "Like should I clamp the pieces tighter?" If you're using any form of PVA glue, white or yellow, then yes. You do then need to take extra care to balance clamp force, but high clamping pressure isn't just desirable, it's necessary to achieving good joints. Re. balancing clamp pressure see guides to clamping up panels online. Re. clamp pressure, see this previous Answer of mine.
    – Graphus
    Commented Aug 1 at 6:32
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    Absolutely. Dowels are great here to keep everything lined up while clamping against wet glue. Excellent idea.
    – gnicko
    Commented Aug 1 at 15:15
  • Good point about taking out that center wood on the left side board.
    – Zeye
    Commented Aug 3 at 21:25

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