Just a little watch out for this suggestion for others…
I generally use the T Slot rails I’ve got built into my table to clamp down my work, and because these are pretty well secured (and because I’m a little heavy handed), I’ve gotten into the habit of clamping things down pretty tightly.
I recently found however when I was using the threaded inserts I’ve got installed, my usual clamping enthusiasm was actually pulling the MDF up into a dome shape. Having apparently done this a few times,it now explains why I was getting some weird errors on work that “should” have been perfectly flat.
My wasteboard is 19mm MDF which I guess is up around 3/4" in the old money and I think the threaded inserts are 5/16" or so. I also use aluminium clamps which are also pretty robust.
Just thought it a little tidbit worth passing on, if it save one job, it’s worth it I guess.