1/8 baltic birch

[Vic Harris]

How is everyone keeping their stock flat?
At prewsent I an stacking with a weight on top but would like more ideas if anyone can offer them.
Thanks in advance!
Vic :confused:

[Lonny Meeks]

I put the "high" side (bow) down and tape all the sides down. Still not keeping it completely flat but helps.

[Vic Harris]

Thanks Lonnie!

[Wolf Nitsch]

We just put something heavy on a stack keeping the bow up as stated before. Works ok.

[Judith Halliday]

I don't keep much of that stuff. What I have is under 2 cinder blocks. Just make sure you put a fabric between the items to keep the wood from being scratched.

Cheers...

[Phil Garcia]

I use two of my 10lb. weights from my weight lift set for my with a sheet of printing paper between sheets.

[Michael Kowalczyk]

Hey Vic,
We keep ours wrapped in Kraft Paper to keep the humidity out and do this as soon as we cut it down to size. Horizontal grain will tend to bow more than vertical grain. We stock both but it will depend on your application as to which one is better suited. If you you are cutting projects longer than 12" when you use a 12" x 24" sheet, horizontal grain will provide greater strength/rigidity. If you are cutting smaller projects like Laser Buzz ornaments, then a vertical grain is another option. It lays flat and if grain direction is important then rotate your project 90 degrees.

If you are applying a clear coat to your material prior to lasering, you should apply it to both sides. If you only seal one side it will cup/bow.

You may get some bowing if you have a high humidity level or extremely dry air because of your location or forced hot air system. Try to control the humidity level as best you can.

Also please check to make sure you are getting "Genuine Russian/Baltic Birch Plywood". I have heard of some people trying to sell Chinese birch because they can not get "Genuine Russian/Baltic Birch Plywood". It has a high humidity level to begin with and cups/bows immediately after it is cut. We tried it once and will not buy it again.

Let me know if you have any other questions and ...

[Richard Rumancik]

Storing with weights applied may work in some cases but it is hit and miss as to whether it will end up flat. Using some weight on the material during cutting can help but it usually interferes with lasering and you have to be careful not to have a collision with the carriage. Small flat steel plates can be helpful.

If cutting multiple smaller pieces, one possibility is to place the material on the laser, lock it down somehow, and pre-cut some separating lines which miss the parts to be cut. You should put this on a separate layer. A vertical line and a horizontal line like a "+" sign should help. (They lines don't need to be straight.) The cuts will weaken the center of the material and hopefully cause it to drop down flat on the grid. Best if you don't cut right to the edge so the pieces stay together. This pre-cutting will take some laser time, but compared to wasting the parts trying to get them out and/or reworking them, it may be still advantageous.

Another option - focus on the center (raised) section of the panel, and set up the cut sequence to cut the most centered part first. Then pause the machine and lay a flat weight in this area. Re-focus the machine for the remainder.

I find that with warped birch I am usually better off using smaller panels if possible because a large 25 x 18" panel will rarely sit flat.

[Vic Harris]

Many thanks to all!!! Great info Michael.

[Ray Uebner]

Great ideas all. I also have mine weighted and help most of the time. Duct tape works great for keeping it flat when engraving.