Hi there! Moderate-time reader, first-time poster. Sawmill Creek has been a great source of tips and inspiration.
Anyway, I do laser cutting and engraving, and like many others I've ended up with baltic birch as my material of choice. My laser cuts through it like butter, except that I'm having a problem that I haven't seen mentioned anywhere in the discussion of this material.
It seems like the inner ply is pocked with something resistant...little pockets of sap, maybe. The laser hits these and fails to cut through them. I cut 50-60 pieces from a pieces of 30"x"30" birch, and maybe six of them refuse to come out cleanly. I'm finding that I either need to do multiple passes (slow), use high power (musses up the backside) or just touch up those spots with a razor blade (not always possible, ex. curved cuts).
Has anyone else run into this issue? I doubt there's a workaround, unless this batch of birch is suspect, so I'm just looking to commiserate.