This thing is crazy comfortable, like a big, inhabitable shell that is soft on the inside. Pretty cheap to make, though the end product is a little heavy and bulky.
Step 1: Preparing the Barrow
I got my wheelbarrow for free by posting a wanted ad on craiglist. They are also plentiful at the dump and in suburbua in general, where people tend to buy them for one or two projects and then never use them again. Ask around.
This wheelbarrow had been used to mix concrete. I removed the cured cement with a hammer and screwdriver. Light, rapid taps will crack a lot of it off; get the rest by chiseling and scraping with a flat head screwdriver.
Then I used a Dremel to cut the bolts that held the frame onto the barrow since they were rusted together. The rest is staightforward and heavy on the elbow grease: sand off the rust and old paint with 60-grit sandpaper, then 100-grit, then wash the loose rust, dust, and paint off with a stiff brush and hot soapy water. Last, clean it again with a rag and denatured alcohol.
Step 2: Legs!
The legs are attached with 3/8" machine bolts. I counter-sank the holes for the bolts to give a nice finished look. Pop a 1/4" hole about 3" up from the floor end of each as well, for the tension element later.
I won't make you suffer through the pictures of finishing the wood, but, after a thorough sanding, I put on three hand-rubbed coats of polyurethane, with light sanding in between coats. I finished it off by polishing with 0000 steel wool to get it smooth and shiny.
Step 3: Painting the Barrow
Step 4: Stand Up
I also covered the holes from the original frame with neoprene fender washers, attached with flexible cement and machine screws through to metal fender washers on the inside. This was just to clean up the rough stuff so no one would cut their finger, and also so the colored cushions couldn't be seen from the outside.
Step 5: Tourniquet
1. It helps to self-level the chair by subtly (and not-so-subtly) twisting the legs and the frame the legs are attached to.
2. It counteracts the tendency for the legs to spread outwards when loaded.
3. It exerts an opposing force on the bolts that hold the legs onto the chair, creating a tension that is again self-correcting over time, keeping the thing straight and level over long periods.
4. I think it looks cool.
That said, it's not strictly necessary. The chair would be strong enough without it.
Run two loops of string diagonally from opposite legs, through the 1/4" holes drilled earlier. Hide the knots inside the holes in the 2 x 4s. I blunted two finish nails with my Dremel and used them to go inside the loops and twist them tight, just like a tourniquet. They are extremely taut, making a nice open C when strummed. Tie off the nails neatly. I used nylon string, but tie wire or rope would also work.
Step 6: Upholstery
Dimensions, again, will vary, but the main five cushions are all 20" x 8". The pictures tell the story as far as wrapping the foam in fabric -- it's exactly the same as wrapping a Christmas present. Instead of scotch tape, secure it with some simple whip stitching -- basically just big, looping stitches. I put the blue, dense foam as a bottom layer in each cushion, topped witha couple layers of mattress pad. Dual-density for maximum comfort.
For the two side cusions, make a template out of newspaper. Remember they are opposing, symmetry-wise, so the finished side on one cushion will be the unfinished side on its opposite.
Step 7: Finishing Up
Once the glue dries, snap in the cushions. Everything should be really snug and tight.