This is a totally mobile, sturdy workbench. It will fit through doors and has a bottom tray for tools, as well as a shelf for a toolbox. It also has a power bar and cable storage incorporated into the design.
Step 1: Buy the Frame
All big box building and auto stores have folding workbenches. These typically have a small work surface that can be used as a vise to hold material. They fold flat for storage but are simply not tall enough and are rather flimsy. To begin, remove the plastic feet from all four legs and measure the width and length across the bottom.
Step 2: Build Bottom Tray
Build a tray with the same inside dimensions that you measured.Mine was 20 x 25". I made mine from an old butcher block counter top and added 4" side rails. Attach industrial locking casters to the bottom four corners. Set the workbench in the tray and drill through each leg so it can be bolted securely to the tray.
Step 3: Make a Work Surface
I cut another piece of the butcher block to 20 x 25" for a work top. I added a cleat to the bottom so that it can be clamped to the existing table top. It can be easily installed or removed by simply tightening or loosening the table's clamping device.
Step 4: Make a Shelf
In order to provide access to the bottom tray, move the front and rear cross-braces up a bit. They are held by two bolts in each leg. I found that by using the existing top hole as the bottom and drilling a new top hole, I was able to get enough clearance and use the existing bolts to re- install. Measure the length and width and cut a shelf to fit.
Step 5: Make New Side Braces
Remove the flimsy metal side struts by pulling out the rivets. then make new side braces. First, level out the entire structure. Measure across the legs, or trace the profile on pieces of 1 x 6 wood and cut to fit. Make sure you drill two holes through the wood and each leg and bolt securely, or else the whole bench will flex. I added a power block to one brace and a cord winder to the other. That's It! I still have to take it all apart, sand the wood parts and give them a couple of coats of varnish.