My question is: why two layers of MDF? You know that that stuff is twice
as heavy as plywood and it tends to take a "set" over time.

I'd be inclined to make a torsion box for under the butcher block top. To
do that, make a frame using some very straight 1X2 or 1X3 stock (poplar
should work well). Be sure to add cross members approx every 20". Glue,
screw and clamp the frame securely to a known flat surface (table saw?)
while it dries. Use 1/2" or 5/8" ply for the top and bottom glued, screwed
and clamped to the poplar frame and the known flat surface.

The torsion box should be MUCH lighter and stronger than MDF and, if
assembled correctly, should remain flatter for a long period of time.

"RayV" wrote in message
ups.com...
My last project (Maple cutting board) has determined what my next
project will be - a workbench. The weight and clamping abilities of a
'real' workbench should make working on future projects more enjoyable
and less frustrating.

Here is what I am planning and would appreciate any advice.

The base will be constructed much like the bench in the Nov. '05 issue
of Wood.
http://store.woodstore.net/trwo.html
I will be using PT-SYP because it is heavy and I have it.

The top will be a 1" Oak butcher-block table ($40 at second hand
store) on top of two layers of MDF. I think I will attach it this
way:
Drill slightly oversize holes in one sheet of MDF then screw that
piece to the Oak using Liquid Nails as glue since the Liquid Nails
stays flexible. I will countersink the holes between the two panels
so the material displaced by the screws won't push the panels apart.
Drill holes in the second sheet of MDF and screw to the first, again
with countersinks on the backside. Wrap the top with Maple.

The front vise will be made using this hardware from Grizzly with the
inside jaw being the apron and the outside jaw being 3 layers of 3/4
Maple.
http://www.grizzly.com/products/h7788

The tail vise will be made using this hardware from Lee Valley and
will probably be similar to the Nyquist style vise made out of Maple.
http://www.leevalley.com/wood/page.a...64&cat=1,41659

The finished top will be 30x60 with no tool tray and 3/4 dog holes and
36" off of the floor. The 36" is higher than my TS but maybe that
will motivate me to build this.
http://www.woodmagazine.com/woodmag/...asymoverbg.jpg