Boneheaded Noob Move of the Week

Measure twice, cut once, not the other way around.

The shelves in the kitchen cupboard that is missing a shelf are 33" long, not 32" long. Which means having the MDF stock cut to 32" produced shelves that are Just Too Short. As in, fall off the shelf brackets. Wah.

And yes, even though MDF is not milled down from raw board stock, nonetheless 10" MDF boards are only nominal 10" boards, because they match the standards of other board stock which is milled down from raw stock. Bother. I should have guessed that on my own. Not checking the width on the boards was the real noob move. Because when you're replacing missing 10.75" shelves, deciding that 10" is close enough because 12" is definitely too wide is completely wrong because the nominal 10" boards aren't 10" wide, they're closer to 9", which is Just Too Narrow.

So I went and bought another MDF board, this one a nominal 12" x 8' and had it ripped down to 10.75" and cut to two 33" boards and a stump.

Which doesn't fit because the either the cupboard is out of true, or the board is warped. MDF has no frakking grain. It's not supposed to warp. Goddammit, where's my hack saw?