Why can' I make square flat stuff

how was your mdf stored ? i can tell you from experience that mdf can still be
out of flat especially if you leave it on edge for a few days. i had this happen
to me with a 1/2” sheet.

-- Yves

Everything was stored on edge for quite some time. I share my 1 car garage with all the other junk we have so I have no space to lay things flat.

Is that the problem. The wood was bad from the get go? Can that be fixed with some magical wood working technique?

This might happen if you didn’t drill pilots for those screws. MDF is dense and will spread.

-- Failure does not stop me, it makes me try harder..... because I'm crazy.

I know this doesn’t help with your current table, but if you end up remaking it at some point you might want to consider building a torsion box design, which would be lighter and very resistant to going out-of-flat. Good luck!

-- John, BC, Canada

Russ, I drilled pilot holes all over the place.

NW, I was thinking torsion box but those things are complicated and are kind of deep. I’m not sure I have that top to bottom space. But it looks like that might be what I end up doing. I need to keep it under 4.5 inches.

Thanks,
Mark

Are you sure the surface you have it on is flat ? 3 sheets seems like a bit of an over kill. If you had a bow in all of the sheets I could see them having a twist or bow but only to happen on the last sheet seems a little odd. Have you used a straight edge or string line to check the top?

-- W James Brokenbourgh Custom furniture maker http://artisticwoodstudio.com/

I hear you Mark. Maybe try with 1/2” material on a torsion box if you go that route. Yours would be a bit trickier to build due to the cutouts, but I think it could be done. I am gong to have to go that route on my assembly table (same problem, laminated two layers of 3/4” MDF and 1/4” hardboard on top, and not flat…)

-- John, BC, Canada