Warped walnut

[Frank Gilbert]

I have a 22 inch by 22 inch walnut table top that separated along the middle glue line and each half warped. The walnut is about 5/8 thick and has been warped for several years. The table was handed down by family and thus the effort to repair.
I have tried water on the convex side and heat lamps on the concave side and even wood strips clamped to create pressure. Nothing is happening and without a better idea from the forum the next step is to make cuts in the underside of the boards and fill with a thin piece of weaker wood. This technique is described in a book by Ernst Joyce.

I would be grateful for any advice.

[Dewey Torres]

Frank,
Please go take a couple digital pictures and post them here.... We will try to get r' solved for you.

[Chris Padilla]

So I assume each piece cupped like: /-\ /-\

So you're trying to expand the underside to flatten the top?

Do you have any pictures? Can you removed the top to work on it?

[Frank Gilbert]

Hey thanks for helping. The top is off and in two parts. The cup or convex surface is the top __facing up.
Would be glad to post photos, however, unclear how to get that done.

[John Keeton]

I have tried water on the convex side and heat lamps on the concave side ...

Frank, this sounds the reverse of what it should be. The concave side should be moistened to counteract the expansion that has occurred on the convex side.
Having said that, it it has been cupped for years, I doubt you will have much success in this endeavor short of some structural alteration. But pics may help get some other opinions. In order to attach a pic, it must be reduced in size and resolution to meet the maximum file size (105 kb I think), and then when you post, click the paper clip icon and upload the pic from your computer.

[Dewey Torres]

Would be glad to post photos, however, unclear how to get that done.

Frank,
1) Take digital picture
2) Hook up camera to computer and save digital picture to desk top (or wherever) on your computer.
3) Hit: post reply
4) click on the paperclip icon just to the left of the smiley face at the top
5) hit browse in the new window that pops up
6) point the browser to your picture location
7) hit upload... wait for indication of upload
8) close window
9) submit reply

[Frank Gilbert]

Concave top faces up and it is two pieces. I think I said that backward. Thanks. Will send pic tomorrow when brain may be engaged.

[Frank Gilbert]

I have removed the top.

[John Thompson]

Not sure from the picture what you mean by two pieces. From what I see you might follow Joyce's advice and do the stress relief cut. But.. I would add a stretcher under-neath from side to side that will not be seen. Shoot some pilot holes in it and then run spax screw through it into the top to attempt to pull it down. But.. be careful not to run the screw through the top as 5/8" is not real thick.

BTW.. I do this on all my tops. I use table fastners snugged in a groove on the outer strechers but with enough room in the groove to move in and out in expansion and contraction. In the center which is most likey to cup with flat-sawn stock... I run the strecher from side to side and pull it down with screws. That pins the center so expansion and contraction are forced to the outer perimeter where the loose fitting fastners can move back and forth in the groove.

Good luck and a picture of the two pieces might help as I am still not quite sure what you refer too..

Sarge..

[Tony Bilello]

Looks to me like it needs to be sliced lengthwise in 3 places. Then use table saw or planer to cut edge to appropriate angles and reglue. When done, it will need to be planed or belt sanded so the ridges can be flattened.
Yuo will probably lose about 1/2 to 5/8" off your total width, depending on skill level. Only 3/8" to 5/16" if you are really good and have a narrow kerf table saw blade. Probably lose about 1/16" to 1/8" overall thickness depending on how much of the ripples you can live with. It's all a matter of what you are willing to live with.
If you try to pulll it flat with screws it will still have waves/ridges and will eventually crack somewhere and that may not be a straight line glue joint crack and your problems will be worse.
Itsa
I used to have a woodworking and refinishing shop, if that will add any credability to what I suggest.

[Ralph Barhorst]

If it was my table, I would get some nice figured walnut and make a new top 3/4" thick. Try to match the edges to the old top.

[John Keeton]

I am with Ralph on this one! Any effort to repair will be visible, and will detract from the value and appearance of the table. A new top could be a "transparent" repair and actually increase the value. Of course, one would have to conclude the sentiment is in the table, not the top.

[Frank Gilbert]

I really appreciate all the responses. Thank you.

[John Keeton]

Frank, that looks like a glueline failure. Probably hide glue if original, and subject to moisture and heat - which may have been the cause of the warp/cup.

I would seriously doubt that this can be corrected in such fashion as not to be noticeable. I would replace the top. That is a simple ogee on the edge and easily duplicated.

[Frank Gilbert]

I will find some figured walnut per Ralph and make a new top. I have worked on this for quite a while and am very grateful for the guilt relief. Thanks to all.