"Bill" wrote

Another possibility I am willing to consider is using 2 layers of 3/4" ply
(Columbia "Purebond brand hardwood plywood, since it's
Formaldehyde-free--not Baltic Birch). Of course at +$40 a sheet, that's a
pricier alternative. I'll check with with local lumberyards and see
whether they have started carrying the Purebond products (as LarryJ keeps
reminding me to do!) Maybe 2 layers is overkill for this
application...but maybe not--I know stacking layers of drywall is
"routine".

I have laminated a lot of plywood over the years on various projects. I
made some bench tops that had two layers of 3/4" plywood. But over time, I
figured that was overkill for many applications. Unless you are putting
some serious weight on there, 3/4" is plenty. Or laminate up some 1/2 '
plywood or other smaller sizes. For me, it often came down to whatever was
laying around. If I had enough scrap to make it up, that is what I used. I
also glued and screwed any lamination I did. It just made it a little
sturdier (and heavier).

Another consideration is that any kind of mobile bench, stand, etc. needs to
be stable. And the heavier it is next to the floor, the more stable it will
be when you move it. It also provides a substantial platform to mount the
casters. If you are going to move it much or put any kind of weight on
there, I would brace any vertical components well into that base. A
triangle brace made from plywood, nailed or screwed to the vertical
component and tied into the base would definitely make it more sturdy.

Remember, all kinds of idiots and "home handymen" make wobbly crap. But
real men and craftsman make their project sturdy and functional.