This project was pretty cheap in that I only had to purchase the hinges and stains (the latter being optional).
Dremel (With metal cutting/grinding attachments)
Knife/Screwdriver (I used a multitool)
Medium Paint Brush
2-3 Wooden Pallets
1 and 1/4" Screws
Black Spray Paint
Special thanks to ProRock for inspiration!
Step 1: Preparing the Pallet Wood
I only use wood stamped with an "HT" which means that the wood was heat treated and not chemically treated. It's not likely that you will run into chemically treated pallets anymore but better safe than sorry. Also keep in mind what the pallets may have been used for (like transporting chemicals vs bird seed).
My trunk has dimensions of 38" width, 21.5" height, and 17" depth but you can cut your wood to any lengths desired.
After you have decided on the dimensions of your trunk, cut the wood to your desired lengths, then place them how you want them to fit and double check to make sure they will all fit together. After that, it's time to sand. I used a palm sander and only sanded each plank of wood lightly to keep some of the weathered look.
Step 2: Assembling the Outer Frame
After the frames are assembled place your bottom frame on the ground and place your floorboards inside to check the fit (If they fit snugly you know that you measured correctly). Once the floorboards are in place flip your whole bottom piece over (floorboards and frame) and press each board down to the ground (this will ensure your floorboards remain in place for the next step). After doing this, drill two holes and screw (1 1/4") on the two small pieces of wood used to keep the trunk off the ground. Now flip the whole bottom back over and press the floorboards down to where they will permanently be at the bottom of the trunk.
With the three floorboards secured together, it's time to secure them to the bottom frame. Drill three holes along the length of the base, through the frame and into the boards, followed by three screws (1 1/4"). Repeat on the shorter side of the frame. I found that it was easiest to get most of the screw in with a power drill and then finish the job with a hand screwdriver.
Step 3: Assembling the Sides and Attaching the Upper Frame
I used a C-Clamp to hold each side board to the bottom frame and then screwed them in place using two 1" screws per side board. Be sure to screw them in on what will be the inside of the trunk so they will not be visible. Also start laying the boards from a corner and work your way to the other side. If there is a small gap at the end (like in mine) don't worry about it, it will be covered in the next step with corner pieces.
Once all side boards are in place, fit the top frame around the top of all the side boards (it should fit snugly around all of them). Attach each side board to the top frame using the same method as the bottom (two 1" screws each).
Step 4: Corner Pieces
Measure the space in between the top and bottom frames, this will be the length of wood you'll need to cut and fit. There will be a total of eight pieces to screw to the trunk (two for each corner) using two 1" screws each.
Step 5: Staining the Trunk
Step 6: Building the Lid
The assembly is pretty straight forward. Once each board is cut to length and sanded, I attached them all together using 1" screws and two small boards. I then stained and applied a finish to them like the rest of the trunk.
I purchased two large hinges from a hardware store but they were too long on one of the ends for the trunk so I cut them to fit with a metal cutting wheel on my Dremel and then sanded them down and drilled a new screw hole. After touching them up with black paint I attached them with the screws the hinges came with.
Step 7: Finishing Touches
The final touch is the hidden compartment at the bottom of the trunk. It's a pretty simple design as I just screwed in a piece of wood on each side of the bottom interior. They were about two inches high so the secret compartment would have about a two inch clearance. I chose this height because it's a little lower than the height of the bottom frame so it's pretty difficult to spot that it has a false bottom but it still provides a nice sized secret storage area.
Three boards (two large and one small) fit the space perfectly and one even had a knot in it which I punched out to use for a finger hole for easy opening.
That's all there is to it. If you like this Instructable send it a vote in the Secret Compartment and Doors Contest. As always keep building and have fun!