Lance,

I've built several of these over the past few years with the last one being
an "L" shaped hobby-bench, (7' long each way). The top was made from a 3/4"
thick MDF with a 1/4" thick hardboard top. I built a frame using 2x4's
which I milled down to 1-1/4" x 3-1/4" to be sure they were square. I made
a box frame with cross bracing dado'ed into the long frame members at 16"
intervals and the 2x4's were used on edge. The frame was setback about 3"
(not critical) from the edges of the MDF top. I then pre-drilled,
countersunk and screwed (#8's 1-1/2") the MDF to the frame. In essence, the
frame then became a torsion box - real solid. The 1/4" sacrificial
hardboard was placed on top and held down all around the edges with slightly
countersunk screws (#8's 3/4").

Under the lip of the top - all around the edge, I milled up some 1" thick x
3" wide poplar (3/4" thick pine will work fine) and pre-drilled and screwed
and glued this to the MDF top (underneath) making a 3/4" x 3" wide solid
wood edge that can be used to attach the (1-3/4" wide x 3/4") thick apron I
made from poplar. I did miter the ends but used a FF biscuit at each miter
but you could use a dowel or a spline or simply cross-nail the miter. This
"solid" wood piece not only allows for attaching an apron (use screws) but
also serves as a clamping edge so the MDF isn't damaged.

With the torsion box frame there is no bounce to the tabletop and it's
plenty heavy. On this bench, I made two pedestal ends that had 3 large
drawers in each and made the height at about 41" so she (SIL) could stand
and work comfortably or use a stool and not be bending over when she's
working on crafts. The whole bench was designed to be dismantled and moved.

I think that answers all your questions and hopefully the ASCII art below
will help. You may have to open your email window to full view so the art
comes out correctly. If I can find the pics I'll post them to abpw.


___________________________________
___________________________________| 1/4" Hardboard - Sacrificial top
|
___________________________________| 3/4" MDF top
|
___________________________________| 3/4" x 3" wide pine board all around
|
the apron attaches to this with screws
|
covered with wood plugs to hide them
|
|
|
|
| 1-1/4" thick x 3-1/4" wide frame ~ 3"
setback
_____________ |


Bob S.



"lance" wrote in message
ups.com...
I'm in the process of finishing the base of my first workbench. I have
decided to go with a laminated MDF top, with masonite on top of that.
I am trying to figure out how to attach an apron to the top and can't
come up with any good way. Since this type of top seems to be somewhat
popular, I would like to see how others have done this. How is the
apron physically attached to the MDF? How did you do the corners of
the apron? I was thinking to miter them and glue in 2 dowel pins, but
I'm not sure if that is a good method. One other question is how did
you go about mounting the MDF top to the base of your workbench?
Thanks so much.