Bowing problem with Chess board

[Mike Conley]

I recently made a chess board with squares of purple heart and maple which I glued to a piece of 1/4" plywood.

After glueing the wood squares to the plywood base, I placed the chess board on a flat surface with a stack of wood on the chess board while the glue dried. Apparently I did not leave the weight on the board long enough because the chess board is now bowed. :(

I have cut slots in the plywood base to try to relieve tension on the underside and make the board flexible enough to remove the bow. This has helped some but it is still pretty hard to hold flat on one side.

Does anyone have suggestions on what else I can try to remove the bow? I plan on framing the board, but I am afraid the frame will not be strong enough to hold the board straight.

[harry strasil]

did you try spreading glue on the bottom side to pull it back?

[David DeCristoforo]

You must veneer both sides! trust me on this. With a 1/4" thick face on one side only it's guaranteed to warp.

[Mike Conley]

You must veneer both sides! trust me on this. With a 1/4" thick face on one side only it's guaranteed to warp.

I did not use veneer. I used solid squares of purple heart and maple.

So, are you saying I need to glue some solid wood on the under side to pull it back.

[David DeCristoforo]

That's still veneer. It's just really thick veneer. If you match the thickness on the "back" there is a chance the panel will stay flat. You don't need to use expensive wood or even squares. Just a "balancing" layer. Also, with this kind of construction, the "veneers" should not be more than about 3/16" thick. Even at 1/4" thickness, you are pushing your luck.

[Jim Finn]

I did not use veneer. I used solid squares of purple heart and maple.

So, are you saying I need to glue some solid wood on the under side to pull it back.
I have made chessboards of the same materials and I had a similar problem. I just glued and clamped the whole thing to another thicker piece of plywwod and it worked out great.

[Tim Dorcas]

David has this one covered. You must veneer both sides to prevent bowing.

[Mike Conley]

That's still veneer. It's just really thick veneer. If you match the thickness on the "back" there is a chance the panel will stay flat. You don't need to use expensive wood or even squares. Just a "balancing" layer. Also, with this kind of construction, the "veneers" should not be more than about 3/16" thick. Even at 1/4" thickness, you are pushing your luck.


Sounds like I may have to scrap this board. My "veneer" is 5/8" thick.

David - I have looked at the chess boards you make. They are beautiful. Do you mind giving me some suggestions on the best method for making a chess board?

The board I was working on was going to be for my Father-In-Law for Christmas.

[jason lambert]

Run it throught a drum sander to thin the top vineer and then vineer the bottom as well.

[Joe Jensen]

Mike, solid wood moves with changes in humidity. A finish on the wood will slow the movement, but not stop it. I have a red oak kitchen table that is 36" wide. I live in AZ where it's pretty dry all the time. My table top changes width by 1/2" over the year. Further, wood moves width wise, and thickness wise but not really length wise. Quarter sawn moves the least and flat sawn the most.

Plywood on the other hand does not move. The way you built your board, you glues squares that WILL move to a substrate that will not. If your substrate was so strong that it won't move, then the squares will crack in some places during the dry months.

[David DeCristoforo]

"Do you mind giving me some suggestions..."

Not at all. Two words: Solid wood. "Long grain" glue joints, no problem. End grain joints, big problem. Go back and look at this page:

http://www.daviddecristoforo.com/chessdd/boards.html

down toward the lower half of the page is a small picture of a "finger joint" that I use. It's milled on a shaper with a power feeder and with the stock between the cutter and a fence. This joint provides a substantial "long grain" gluing surface on the end grain joints. I tried many different techniques before settling on this and this is the only thing I have found that actually works.

I used to make boards with thick veneered squares similar to what you have made but they were never stable enough. Joints would open or the squares would not stay flush or they would crack. Besides, I always wanted to make solid wood boards. I "float" the squares in a frame similar to the way in which a panel floats in the frame of a door.

The only other workable option is to make veneered boards using thin veneers on a stable core. But this is not the kind of thing I wanted to make and there are tons of cheap veneered boards out there.

PS Krenov made boards in which the squares were all "discrete" and joined with dowels with a space between each square. Interesting way of overcoming the problems. There is a bit on it in one of his books.

[Mike Conley]

I "float" the squares in a frame similar to the way in which a panel floats in the frame of a door.



Thanks David.

Do you capture your board in the frame like A, B, or C in the sketch below or some other way?

[David DeCristoforo]

I have used all of those configurations as well as using a spline which creates an intentional "reveal" of +/- 3/16" between the frame and the squares. The spline can be of a contrasting color to add visual interest. Your drawing "B" is my "favorite". "A" is not so good because of the possibility of "gapping" between the frame and the squares.

[Jim Myers]

I am planning on making a portable chess board that folds up and the pieces fit inside for storage.

I was wondering since I read this if I will have a problem with bowing or do I need to make the squares out of thicker material to help prevent it.

I know it will not be light weight by any means as the chess pieces I am going to use are the Woodcraft kit and they have some mass by themselves.

I just want to build something that my son can grow with and have for a long time.

Thank you

Jim

[Howard Acheson]

I assumed you used solid wood squares and then glued them to your plywood. That will not work. The solid wood will expand/contract with changes in relative humidity while the plywood will remain stable.

To do what you want to do, you should have your squares no more than 1/4" thick and they should be glued to both sides. Also, the grain in each square should run in the same direction.

[Mike Conley]

Not at all. Two words: Solid wood. "Long grain" glue joints, no problem. End grain joints, big problem. Go back and look at this page:

http://www.daviddecristoforo.com/chessdd/boards.html

down toward the lower half of the page is a small picture of a "finger joint" that I use. It's milled on a shaper with a power feeder and with the stock between the cutter and a fence. This joint provides a substantial "long grain" gluing surface on the end grain joints. I tried many different techniques before settling on this and this is the only thing I have found that actually works.

Could I use bisquits to join the end grain????

[David DeCristoforo]

"Could I use bisquits to join the end grain????"

I have tried everything to join solid wood squares end to end. Trust me... biscuits will not work. Nor will splines, T&G joints, dowels, steel rods, "V" grooving, praying, pleading or begging. Sorry. Sooner or later (in most cases sooner) the joints will fail.

[James Biddle]

David,
Beautiful work. Are you using a "reversible glue joint" cutter? What type of fence do you use for shaping the stock between the cutter and fence?
"Do you mind giving me some suggestions..."

Not at all. Two words: Solid wood. "Long grain" glue joints, no problem. End grain joints, big problem. Go back and look at this page:

http://www.daviddecristoforo.com/chessdd/boards.html

down toward the lower half of the page is a small picture of a "finger joint" that I use. It's milled on a shaper with a power feeder and with the stock between the cutter and a fence. This joint provides a substantial "long grain" gluing surface on the end grain joints. I tried many different techniques before settling on this and this is the only thing I have found that actually works.

I used to make boards with thick veneered squares similar to what you have made but they were never stable enough. Joints would open or the squares would not stay flush or they would crack. Besides, I always wanted to make solid wood boards. I "float" the squares in a frame similar to the way in which a panel floats in the frame of a door.

The only other workable option is to make veneered boards using thin veneers on a stable core. But this is not the kind of thing I wanted to make and there are tons of cheap veneered boards out there.

PS Krenov made boards in which the squares were all "discrete" and joined with dowels with a space between each square. Interesting way of overcoming the problems. There is a bit on it in one of his books.

[David DeCristoforo]

"Are you using a "reversible glue joint" cutter? What type of fence do you use..."

The cutter is "reversible" but it's more like a finger joint with three "fingers". The "fence" is a simple 3/4" MDF strip bolted to the shaper table. Running the stock between the "fence" and the cutter results in all pieces being exactly the same width. Needless to say a feeder is a must! I will post a pic of the setup next time I run some boards....

[Charlie Plesums]

...
I was wondering since I read this if I will have a problem with bowing or do I need to make the squares out of thicker material to help prevent it.
...
The trick is to make the squares thinner rather than thicker. Thin (veneer) will move with the substrate (or not move if a plywood substrate is used, which does not move). Thick will move with the squares, and will likely split or pop off the substrate if they do not move together. If you do a good veneer job, it will be indistinguishable from solid wood blocks.

[Jim Myers]

Thank you for the information

[Sean Rainaldi]

"Are you using a "reversible glue joint" cutter? What type of fence do you use..."

The cutter is "reversible" but it's more like a finger joint with three "fingers". The "fence" is a simple 3/4" MDF strip bolted to the shaper table. Running the stock between the "fence" and the cutter results in all pieces being exactly the same width. Needless to say a feeder is a must! I will post a pic of the setup next time I run some boards....

David, absolutely beautiful work!

If I may ask, what kind or brand of power feeder did you use on your shaper? I have been looking for one for small parts.

[David DeCristoforo]

"...kind-type of a feeder..."

Shaper and feeder are both from Felder (KF700 Pro saw/shaper) Pics of it here:
http://www.daviddecristoforo.com/Misc/shaper/ (just the shaper, not the feeder)

[Sean Rainaldi]

Thanks very much David,

Actually I was wondering (not to change the subject of this thread although it does relate), I have been thinking about building a scrabble board. For cutting the small square scrabble letters, would a cabinet saw be reccomended? Or should I invest in a small minirature type of table saw that model builders use?

Or would a band saw be better - safer?

Also what method would you reccomend to square up the small peices?

[David DeCristoforo]

"...small square scrabble letters..."

You might be better off posting a new topic for this. It's going to be buried here.