I have a new table that I am building. The table is 6.5’ x 42” and is red oak with 6” walnut butcher-block ends and 4” walnut on the sides. I also have a 4” walnut strip right down the center. I used type II yellow glue. This might be important if I need to get the wood wet. It is not finished. I found that one of the sideboards has a small warp in it. I thought this would straighten out after gluing the oak to its side and putting it through the surface plainer; however, it pulled the oak into a warp instead. I now want to straighten the walnut without causing too much damage to what I have already done.

Please let me know what the best course of action is. The following are a couple options that I thought of: 1) cut the butcher-block ends off and the two sideboards and replace the warped walnut and start over. I really do not want to do this. 2) cut some relief cuts on the underside of the table under the warp, add a 2” piece of walnut under the table as I clamp it making sure it is straight, then add a .5” piece of walnut on the outside edge covering up the relief cuts and the second piece of wood. I can then use the router on the edge and the extra wood would blend in. The table will took 1.5” thick instead of .75” but that is okay. 3) use the router, make a .25” grove under the table along the length of the warped walnut and screw a piece of metal in the grove, pulling the warp straight. 4) soak the side of the table with walnut in water and let sit for 15 minutes and then while pushing the board straight use a heat gun on the convex side of the walnut.

These were some ideas that I came up with but do not know which would be best.

Please help

Vern

 

If I understand your post correctly, the walnut is cupped, so that one piece of the table top is concave? Was this piece installed with the crown up to begin with? I've read the post several times and its a little confusing. Oak is warped but your want to straighten the walnut. Maybe a little clarification or a picture?

 

Yes, the crown was up. I would send a photo if I knew how; however, I don't think you could see the warp in the photo. It is very slight.

 

All the pieces of wood were without warp except this one 4” piece of walnut. It was warped slightly so it was cupped in the center all the way across the 4" of grain, like a bow. I thought that the other boards would pull the warped board straight as long as I clamped and glued it straight. This did not happen. Instead, the walnut pulled the oak into a cupped shape, showing how dense the walnut really is. I had anticipated putting the walnut in the middle with oak on both sides; however, when gluing up, I did not look close enough and put the walnut on the edge. It is only a slight cupping to the board, maybe 3/8” in the center with some warping along a 30” distance; however, it’s a table and I would like it flat without the cupping.

 

I think I understand now. There were too many "cupped" and "warped" in there for my feeble brain to unravel. If it was bowed up you could use a jointer plane or jack plane to plane it flat, but bowed down is hard to fix.

IMO you would want to remove and replace the warped walnut, which should allow the oak to lay flat again. Walnut is not going to bend very well so I don't think your fix it ideas will work well.

But I guess that isn't what you wanted to hear.

Bending it would be difficult, as you may need to OVER bend it just slightly to account for a little spring back. Hard to judge. You could point a salamander heater at it if you could somehow heat the area to between 350-400F, then allow it to cool. But this would also be a good way to wreck your project if not done precisely, as the lignin in the wood will hold that shape permanently once heated and cooled. It would also require about 72 hours of soaking and 1 hour of heating. I'd be afraid to soak your project that long. Hard telling how it might affect your oak. It could cause more harm than good.