[lilman]

Working on a round chessboard for a coworker. Consists of a base about 2.5 inches thick which will hold the pieces and a top that will have the chess squares set in. After routing out the top for the squares the top has become bowed a good bit. My question is, does anyone think as I glue in the squares, keeping the top flat, that it will help take the bow out? It's got about an 1/8" bow to it. It's a round 18" glue up, roughly 3/4" thick.

 

[BernieL]

Wood tends to have its' own mind about movement, but there are variables here you need to share. What kind of wood is it? Is it from a cut log since it's round. What is the weather where your at and does it tend to get muggy in the summer and cold in the winter. With as much movement as you describe, I don't think your plan will straighten out the wood. I could be wrong...

 

[Steve Neul]

I assume the top is bowed up toward where you routed it out. I think you would have better luck if you would wet the wood on the inside until if flattened on its own and then clamp it flat while you glue the pieces in. I would keep it clamped for at least 24 hours after you get the pieces glued in.

 

[lilman]

It originally started as a 19x19 square glue up, then cut into a circle. Climate has been pretty consistent I'd say. As for wetting, how wet? Sopping wet or damp?

 

[Dave Paine]

As for wetting, how wet? Sopping wet or damp?

Be very careful when trying to control adding moisture to wood. Sometimes the wood may absorb more than you want, which can result in too much movement, then different warping and when dry cracking.

Start with a light spray. Less is better than more. Easy to add another spray, but hard to remove.

I hope you are able to get this flat, but I would not place a bet on the odds it will move as you desire. Wood, moisture and "Murphy" can be a very difficult combination to battle.

 

[lilman]

I really hope this works...this is my second attempt. If this is yet another fail, the playing area will be raised!! Haha

 

[Steve Neul]

It originally started as a 19x19 square glue up, then cut into a circle. Climate has been pretty consistent I'd say. As for wetting, how wet? Sopping wet or damp?

I wouldn't put it under a faucet but a rag dripping wet should do it. What happened is when you routed out the crevasse it weakened that side of the board and the pressure from the other side just pushed it up. I experience that when I do relief carving on a board. It always bows up on the side I carve on. Wetting the wood will make the side with the crevasse swell causing it to straighten out. Sometimes it takes more than one application. It's just something you have to tinker with. Once you get it flat and fill the crevasse with the other wood it should equalize the pressure.

 

[DaveTTC]

Can you post some pics by any chance. You have some good advice already. I'm surprised you got this kind of movement with a laminated top.

I'm assuming from your description it is a laminated top. Did you alternate the grain direction looking at the end grain. This should help keep the top stable.

I know a guy who does steam work. Adding moisture can help but as said above it can really be an unknown.

If you happen to start again maybe you can do your top 1/2 thickness, glue your chess pieces on top and then glue up a surround to make it flat.

 

[HowardAcheson]

>>>> t originally started as a 19x19 square glue up, then cut into a circle.

You realize that your table is going to expand and contract perpendicular to the grain. In other words, while it was round when you originally cut it, it will get somewhat oblong due to seasonal changes in its moisture content. Routing out the material in the center of the circle is causing further unequal stresses and wood movement. It may never become flat again and any cross grain cleats will exacerbate the problem due future wood movement.

What you want to do is best done by using a composite material like MDF for the substrate and veneering the wood surface and using thin veneer for the checkerboard squares. It's almost impossible to make it work using solid wood. The natural wood movement will be working against you all the time.

 

[lilman]

This is what I have so far. Wet and allowed it to flatten out, then glued, clamped, weighed, and now waiting. Fingers crossed

 

[DaveTTC]

Hope it works for you

 

[lilman]

Update

Murphy worked in my favor for once. Tips were successful, thanks so much to you guys.

 

[DaveTTC]

Update

Murphy worked in my favor for once. Tips were successful, thanks so much to you guys.

We'll want pics.