This folding workbench consisted mostly of materials I already had on hand. It cost me less than $30 to make.
Step 1: Design Constraints
The pictures below show where the bench will go. Before Christmas, this is where my desk was. Now my desk is directly below the camera, rotated the other way--there are perhaps four feet of space between it and the wall. (This was the primary motivation for making a folding bench; I still wanted room to push my chair back.)
My bench design began with a bit of serendipity. I found a discarded piece of 5/8" plywood in the lounge. It measured 24" by 48"--perfect!
Unfortunately, this piece of plywood was pretty ugly.
Step 2: Shellac
I also bought some sandpaper (of various grits) and two removable-pin brass hinges. It was $9 for each of the hinges and $5 for way more sandpaper than I needed, so the total cost of purchased materials was right around $30.
"Sand bare wood as smooth as possible," the shellac said. So I did. This took maybe ten minutes with 220 grit sandpaper. I wrapped a quarter sheet around the back of a blackboard eraser to make a convenient (and incredibly comfortable) sanding block.
Sorry, no pictures of the bare wood--I didn't decide to make an Instructable until after the project was done.
Step 3: Shellac
The shellac directions say to wait about forty-five minutes, sand with 220 or finer sandpaper, and apply a second coat. So I did. It took maybe five minutes to quickly go over all the surfaces with sandpaper. (When it dries, shellac leaves the surface feeling rougher than before--all of the surface wood fibers are now encased in a hard material. Sanding makes a huge difference.)
I went to put on another coat--and discovered that my brush had transformed into a solid chunk of shellac. Oops. Luckily, the directions suggest wiping the stuff on with a rag. This worked well and made my fingers very messy; T-shirt cloth absorbs shellac like nothing else.
I decided that two coats was enough. Another coat or two would've made the wood even smoother. I didn't sand the second coat; there had been obvious scrapes on the wood after I'd sanded the first time. A very fine sandpaper might be okay, but I didn't have any.
Shellac doesn't come off your hands with water. The directions suggest an ammonia solution or denatured alcohol for cleanup. I simply washed up with hand sanitizer and the stuff went away like magic.
Step 4: Install Hinges
I measured in eight inches from each side and laid out my hinges. Once I was satisfied that they were even, I marked each screw location and drilled a small pilot hole. The screws that came with my hinges were exactly as thick as the plywood, so I just went ahead and drilled all the way through.
To decrease the gap between my workbench and the wall, I carved a slight chamfer underneath the hinge with a pocketknife. This allowed the barrel of the hinge to fit better.
Step 5: Mounting the Bench
Step 6: Upper Support
Step 7: Webbing
The next step is to adjust the webbing lengths until the table is level. Water knots are very adjustable, so this isn't a problem. I could even turn this workbench into a drafting table by simply making the supports longer!
Step 8: Done!
Not bad for $30 and an evening's work!