TIL the hard way: my old drafting board in Chicago flexed half an inch after 15 years

I set up a new flatbed in the shop last month and my straight lines changed overnight, found out my old laminated top had bowed from leaning against a radiator, has anyone else had to deal with a warped board messing with their parallel ruler accuracy?

1 comments

1 Comment

shane_wilson4d ago

You ever think a solid flat surface is just solid forever? I used to think that too, until my 10 year old plywood table started showing a slight cup right under my T-square. I would line up a long horizontal line, and by the time I got to the right edge, it was off by a hair. Turns out the draftsman before me had left a full coffee mug ring right there, and the wood just gave up after years of that spot never getting air. Now I check with a straightedge every time I set up, and I had to shim the low corner with some folded paper scraps. It's a humbling fix, but it works until the humidity changes again.