For this project you will need the following (if you want to make a 6' tall shelf like I did):
4) pieces of 3/8" threaded rod (6' length)
8) 3/8" cap nuts
44) 3/8" nuts
48) 3/8" washers
Cardboard to make a hole template.
Nailset or punch
3/8" (or 1/2") drill or spade bit
Phillips screwdriver or bit
9/16" open/box end wrench
9/16" sockets (3/8" or 1/2" drive; deep well works great)
9/16" socket on 1/4" drive adapter to use with a drill (a nut driver would also work well)
Sander or sandpaper
Stain (if desired)
Step 1: Pallet Disasembly
I prefer to use the reciprocating saw to cut all the surface boards free, then pry off the ones that I can't get to with the saw. At this point you can use the hammer and punch to remove all the nailheads, or leave them if you want the added accent. A word of caution if you decide to leave the nailheads: they can be slightly proud of the boards, so be careful when sanding or moving your hand across the boards.
Step 2: Boards and Battens
I wasn't sure if I would want 6 shelves or 7, so I cut a total of 21 boards. I ended up only using 18, but that gave me a little more choice at final assembly.
The battens, or support blocks, are roughly 8-3/4" long to support the 10-1/4" deep shelves. The 3/4" backset allows for plenty of strength and the addition of a trim piece if desired.
After all the cuts were made I used a pad sander with 80 grit sandpaper to knock the edges off and smooth the boards. I chose to leave my shelves natural, and wanted to leave the marking from the manufacturers, so I didn't sand too aggressively.
Step 3: Shelf Assembly
I laid out 3 boards at a time for my shelves; checking for cupping and bends in the boards, mating them together as best as they would fit. With that done, I assembled each shelf by attaching a batten 3" from either end with 5-6 screws in each.
Next I made a cardboard template for where my holes needed to be drilled to accommodate the threaded rod. It's important to use the template because the shelves will not likely be perfectly uniform when made from pallet boards.
Once the hole positions are marked, drill the holes for the threaded rod. I didn't want a lot of play in mine, so I chose to use a 3/8" bit, however a 1/2" bit will make assembly a bit easier.
At this point you're ready to put on whatever finish you'd like. I block sanded with 120 grit sandpaper to clean up the boards a little more, then applied two coats of water-based satin Polycrylic from Minwax.
Step 4: Final Assembly
I tried a couple of different methods to run the nuts down on the rods and here is what worked best for me. It's a bit Rube Golderberg-ish, but using a box end wrench taped to a piece of paint stick with a hole in it worked wonderfully to get the first nuts on. Using one of the cap nuts as a driver, I put a 1/4" adapter on my 9/16" socket and threaded 3' of each rod through its respective nut.
I put a nut and washer above and below each shelf to lock it in place, however the drill technique only worked for the first shelf for me. For the subsequent nuts I was able to stand the rods up, start the but, then drop a 9/16" socket (for a 3/8" drive ratchet) on and spin it down. I used a deep well for several as it allowed me to run two nuts down at the same time (one for the top of one shelf and one for the bottom of the next). Just remember where your washer placement is! I forgot to put a washer on a couple of times and only realized it after I had run the next nut almost all the way to where is would sit.
The process is a little tedious, but not difficult to figure out. Things get more sturdy as you go, and the nits don't have to thread as far each time if working from the middle out to the ends.
Leveling the shelves and adjusting them can also take a bit of time, but that is also what makes it so versatile. If you plan to load the shelves heavily, I would recommend a diagonal brace of some sort. I may add an X of braided cable to the back of mine, depending on how many books I put on it. I also decided to add a couple of the boards from the sides of the pallet for accent and a little extra strength, two on the bottom and one on the top (see the cover photo).
That's it! Tweak and adjust to your heart's content!