Bending wood

[Sasha]

I need to build a 3ft diameter arc from cherry. How do I bend cheery to do this? How thick should the wood be to bend it?

[barry]

I'd make a simple jig using posts to create the arc you desire. They can be just ordinary posts knocked into the lawn, or you could make a complete wooden jig either....

Then Gradually bend the wood around the posts. It will obviously be easier the thinner you can make it, so i'd also consider using thinner wood and building the arc up in layers, glueing each layer in turn.

If thats no good, and you want thicker, then you may have to make some fine cuts across the wood to allow for movement.

Either way, good luck.

Happy woodworking

Barry

[Phisherman]

Rip the cherry in 1/4" or 1/8" strips. No need to steam thin strips. Glue and clamp. Spring back will occur so you want a tighter curve than needed. Sorry I don't know exactly "how much," but I'm guessing around 4%.

[Dr. Deb]

Sasha, one thing you did not specify is how deep that arc is going to be. Are you making a complete half circle or something less. Is the 3' depth or width? In other words, just how big is this thing going to be?

As for the thickness of the strips, the thinner the easier to bend. If the arc is not too deep, the 1/4" thickness would work. If the arc approaches a semi circle, I would opt for 1/8". Also, use a very slow setting glue. You can use yellow wood glue, but make sure the tempiture is above 40 and below 70 degrees F. Also make sure your strips are several inches longer than the length of the arc.

Plastic resin glue is an option, but it dries dark. A slow setting epoxy might be your best choice.

AS Phiserman said, you will get some spring back, since you are doing a "one off" either make the frame fit the arc or make the arc a bit tighter than you need and make the arc fit the frame.

Assuming you have not done this before, take a pice of MDF and cut it a few inches larger than the size of your arc (if your arc is wider than 3/4", cut a duplicate and glue and screw two pieces together) and lay out your arc. Then using either a bandsaw or jigsaw. Cut out the arc and line it with packing tape. Then is is a matter of gluing the strips together and placing them in the form and drawing it together with clamps. Pay careful attention on the clamping process to insure your arc is even in radius.

Then it is just a matter of cleaning up the glue edges and sanding.

Good luck. It isn't hard, just do not get in a hurry. One last piece of advice - USE A SLOW SETTING GLUE. Believe me, you will sleep better with it slowly curing over night than getting a quick cure and having the arc only half finished.

Deb

[eclipsme]

Perhaps you meant steam bending? Then the greener the better. The thicker the wood the longer the steam. Plan for spring back, and the best way I know to proceed is to use some test pieces first.

Good luck, Harvey

[SonomaProducts.com]

Laminating is the best bet. 1/8" strips bent around a frame with the cooresponding outer frame to clamp it down.

One hint that might help is to use bender board (special 1/8" ply for bending) for all of the layers except the outer layer. Also, its best if you use a hard setting resin glue vs wood glue if the piece won't be built into a frame that will hold it in place.

Sasha wrote:

[Doug Miller]

NO! Yellow wood glue will creep. Bent laminations are not stable with yellow wood glue.

That's not necessarily a problem -- he's using cherry, remember?

That would work, but I'd go with a plastic resin glue, mostly on the grounds that the inevitable squeeze-out will be easier to clean up.