Hi Bob
I made an assembly table about five years ago in a different manner:
- frame was from an "office utility table" - 19 mm square steel tube - $10 for a pair at auction.
- top was/is 25 mm MDF, drilled with 19 mm holes at 100 mm centres,
- apron, one side only, was similar to top, also drilled,
- the holes are for insertion of hold downs - I use quickgrip clamps,
- applied three coats of polyurethane.
Assembly table has proven extremely useful and top and apron are still flat - no bending or twists.
However, MDF is very soft and it is now badly scuffed. Poly may have hardenned it a little, but it is still too soft.
If I was doing it again I would want to make it harder; possibly:
- coat it with epoxy rather than poly, or
- make top and apron from something harder, possibly yellow tongue flooring.
Hope this helps
Cheers
Graeme