Workbench for covered balcony
I'd like to build a workbench for my apartment balcony. I've been using a B&D Workmate, but it's time to step up to something sturdier and with storage capability.
The balcony is covered by a roof, so rain only gets in with wind blowing the rain sideways, and the balcony is sufficiently deep that I can place the bench far enough in that wind will rarely drive the rain in far enough to reach the bench, but of course I should plan on the bench getting some rain once in a while.
This will be a general purpose/DIY workbench, so it doesn't need to be built to woodworking bench standards. I'm also trying to keep costs down.
In terms of materials, I'm thinking 2x4's for the frame (doubled up 2x4's for legs) and doubled up 3/4" sheathing plywood and 1/4" sheet of tempered hardwood for the top. Maybe some 1x2 to act as banding around the top and cover the plywood edges.
The top will be used to secure tool platforms (going with tool platforms as opposed to permanently mounting tools so I can clear the bench top when I need the real estate) such as a vise, bench grinder, etc. It will also probably get dogholes at some point. And the top will overlap the frame so that I can clamp workpieces to the top.
Given the exposure to humidity, temperature cycling, and some possibility of rain, as well as the aforementioned uses for the top, would doubled up 3/4" MDF be a better choice for the top than doubled up 3/4" sheathing ply + 1/4" tempered hardwood?
What sorts of finishes for the bench would be best (and preferably inexpensive and easy to apply) to help resist the weather?