On 29 Nov 2004 19:23:01 -0800, (tillius)
wrote:

is 3/4 mdf strong enough to build a cabinet carcass for my shop tools
such as a rolling cabinet for my bench top drill press; mortiser; etc?

MDF is pretty strong, especially in 3/4"

What it's not good at is damp resistance (you _must_ paint, varnish or
at least wax this).

It's also moderately stiff, but not as good as ply, but it has poor
resistance to long-term creep or sag. A cantilevered shelf might look
fine when you make it, it might even hold up the weight you need, but
come back in a year or two and it will be drooping like the "before"
picture a viagra advert.. You really do need to support ends and tie
shelves into back panels etc.

MDF is also dense. This is a nuisance for anything you carry, but for
a rolling tool stand on wheels, it might act in your favour for extra
stability.

You'll also be wanting a biscuit jointer. It's just the best way to go
about MDF carcassing. Rebated laps if you want some positive location,
but go for those biscuits. Screws just don't work. For the "short
grain" problem, neither do lock mitre bits.

Would it be better to use 3/4" hardwood plywood or a dimensional
lumber frame with mdf skin?

Either will work, although I tend to work plywood as 1/2" and use more
panels of it.

I wouldn't go for "skinned studwall" construction. With a thin MDF
skin it's not stiff enough (OK for bookshelves, not for tools that
have high-frequency vibration). With a thick MDF skin you can make
something very big and strong, but I'd prefer to do it with taller
egg-crate internals of MDF as a torsion box. Keeping those skins
spaced well apart improves stiffness.

Here's a plan you might be interested in
http://christophermerrill.net/ww/pla...l_Stand_1.html
--
Smert' spamionam