warped baltic birch

[Kasey Maxwell]

Firstly, I apologize if this belongs in a different forum, I just figured engravers use baltic birch

I have been working with baltic birch for a while now, I'm running into warpage problems over time, I lay them flat on top of each other, the area I live in "Alaska" is quite dry most of the time especially winter, it's not drastic warpage, just twists or bows so I need to tape the edges down so everything cuts properly, if anyone knows of a nice trick to keep them flat and straight or an easier way to flatten them out in the engraver please help

Thanks

[Craig Matheny]

Well I cut a pallet at a time so I end up with about 1400 12 x 24 pieces I keep them in the back room of the house (don't tell my wife) J/K I do keep them there and I cover them with a moving blanket to keep temp changes to the minimal. I still get some warpage and the boards that warp I just use them for straight cuts so they can fall down. Good Luck

[Joe Pelonio]

Storing as flat as possible with weight on them helps but you will be very lucky to ever get a piece that's totally flat. Just the nature of the thin softwood ply to warp. Depending on what's being cut, I have gone as far as to drill a hole in an area as close as poss to the center but outside of any parts to be kept, and run a wire through to the bottom of the vector grid to pull it flat for cutting.

[Chuck Stone]

If it's really a problem, I'll spritz down the sheet with some water, glycerine and
denatured alcohol, lay it flat and weight it down. Then I'll cut it before it completely
dries. Not optimal, but it helps a bit. Works better for veneer than for plywood, but
on 1/8" it's ok. Some people also add wood glue to the mix, but it depends on if
you'll be doing any finishing or not.. the glue will close off the pores. But the water
and glycerine seem to relax the wood fibers for a while, allowing you to work on
it before it curls up

[Michael Hunter]

As Craig says, long-term storage is a good solution to the warping problem.

If you can't afford to wait a year -
Try to get a sheet that is two or three down from the top of the stack - the moisture content will be much more evenly distributed in this one than the one from the top of the stack.
If you won't be using it all straight away, cut it into laser-sized sheets and store it flat with battens between the sheets so that air can circulate. Use the middle sheets first and the top/bottom ones last.

[Rodne Gold]

Perhaps store it in closet with a cheap dehumidifier? Or would that dry it out too much

[Michael Hunter]

It is not so much how dry it is, but how even the dryness is.

Even with a mid-stack sheet, the edges are usually dryer, causing the middle of the sheet to bow and bong a bit.

[Michael Kowalczyk]

The direction of the grain will make the most difference. That is why we offer both Horizontal and Vertical grain. Horizontal is for large parts like LazerBuzz tributes and vertical is for smaller parts like ornaments, key chains.
Sometimes no matter what you do a warped sheet will stay warped and you just have to work around it. Thats why we wrap each box in kraft paper, to minimize humidity seepage, before we wrap it in cardboard and stack them on each other.

When we apply a clear coat of poly on them, we do both sides so they don't cup.

Keep them wrapped and once you open it leave the top sheet on it and put some weight on it, when done, evenly dispersed and supported underneath.

Kasey- make sure you are getting GENUINE BALTIC BIRCH. Ask to see the crate or if you get a full sheet look for the stamp in the corner. Many are selling Chinese birch and claiming it to be Russian birch because they may get their logs from Russia but use a polar core. When you put those two together you get potato chips.

Craig- Nice touch with the blanket.

[Craig Matheny]

Dd not think of this as I have not had an issue with the warpage lately But if I get a piece that has a bend on the edge I put it to the front and hang a 4oz weight tied to a fish hook and hang it over the edge never had it in the way yet. If the back picks up I put it under the lift able ruller just enough to hold it