The goal of this Instructable is to demonstrate how to put secret compartments in plywood. I wanted to prove the concept and see how far I could take it, so I made a lamp using four different compartment styles, and added a secret stash lightbulb and keychain to go along with it.
The designs are meant to be extrapolated and improved upon, so if you want to make an entire plywood desktop, the general concepts should be the same. Check out the video below for a quick demonstration of the lamp, then let's start building...
Step 1: Materials & Tools
For a plywood secret compartment, you need
-(1) 12" by 24" sheet of 1/2" birch plywood
-(2) 12" by 24" sheets of 1/8" birch plywood
If you want to make the whole lamp, you'll also need
-(10) neodymium disc magnets with a diameter of 3/8"
-(1) spring, about 1.5" long and 3/8" diameter
-(1) 3/8" dowel
-(1) 5" by 4" sheet of copper
-(1) Candelabra lamp kit
-(1) Edison bulb
-(1) White candelabra bulb
-(1) Scrap of walnut wood, about 1" by 1" by 5" long
-(1) 2" long, 1/4" diameter threaded nipple with cap
-(1) spare key ring
This list looks long, but the good news is that you can find a lot of these things around the house (or at least I did) and the rest isn't too expensive.
-A variety of clamps (spring clamps and quik clamps work best)
-Drill and bits
-Good tool for measuring and marking 90 and 45 degree angles
-PPE (glasses, gloves, ear protection, and a dust mask)
Step 2: Design
I went about designing the lamp by thinking about the four sides. I wanted each side to demonstrate a different style of secret compartment. When they're all put together, they should just look like four boards of 3/4" plywood, and they shouldn't interfere with each other when opening.
The sketches should be to scale, so if you want to build this yourself, you can print out each on a piece of 8.5x11" paper and use it as a template. Throughout the Instructable I'll say something like "prep materials according to the drawing." This just means to use the dimensions and shapes that are shown on the drawing so that I don't have to try to describe each piece of wood.
Step 3: Style a (Top Compartment)
This compartment will make up the top of the lamp. The compartment is opened using a magnetic "key" that is covered in "Step 7, Keychain."
1. Start by prepping your materials. The scale drawing from Step 2 shows the size of each piece of wood.
2. Glue 3 of these 1/2" strips onto one of the 1/8" boards, leave on of the 4" edges open. Make sure all the corners are square, then clamp the whole thing for about 20 minutes.
3. Take the remaining 1/2" strip, and drill two holes measuring 3/8" into the inside edge, about an inch apart. The holes should be as deep as possible without going through the other side of the strip, so about 3/8" deep. Tap a magnet into each hole, then put a dab of wood glue into the hole and tap a dowel in. Let the glue dry, then cut the dowel flush.
4. When the glue is set, use this frame as a template for the drawer. If everything is done right, the sides of the drawer should be 3" by 4", with the 1/2" piece making up the face of the drawer. Glue the 4 sides and bottom of the drawer together, making sure it still fits within the frame before clamping it.
5. Glue the other 1/8" board onto the frame, making sure the drawer doesn't get glued in place.
6. Use a table saw and/or sandpaper to clean up and square the edges.
Step 4: Style B (Right Compartment)
Style B is a lot like Style A, but uses a more complicated release mechanism, which makes this build a little tougher, but also more fun to show your friends.
1. Start in the same way as Style A by prepping your materials based on the scale drawing.
2. Lay out each piece of wood to check the fit. If you need to make any adjustments, do so until the fit is snug but allows enough room for the moving pieces.
3. Start by gluing the three pieces that make up the edges of the box and clamp for 20 minutes. Once the glue is set, the rest of the fit will be based on these borders.
4. Add the small 1/4" pieces that contain the button and spring system. Glue and clamp in place.
5. Lay out the drawer, and once the fit is good, glue this up as well.
6. Here comes the hard part: fitting together the magnets and the moving pieces. Lay the drawer in the box, and add in the button and spring. If everything that needs to move feels smooth, then good! you'll have an easier time than I did. If not, time to start sanding... Ok now that everything is in place and moving smoothly, mark the spot of each magnet. Don't forget that when the button is in its resting position, the magnets should be (+)(-) so that they attract. When the button is pressed all the way in, they should be (+)(+) so that the repellent force pushes the drawer up.
7. Using the 3/8" drill bit, drill a hole for each magnet. Double check that they are in the right orientation, then seal the drawer magnet with a dowel and the two button magnets with a piece of wood veneer.
8. Glue the last 1/8" board on top, and clamp it shut. Press the button every couple minutes until the glue has tried, to make sure the button doesn't get glued in place.
Step 5: Style C (Left Compartment)
Style C is unlike the other drawers in that it uses a 45 degree bevel on the inside so that you can take one side of the shell off to reveal a shelf. This was the hardest style for me to get the fit right.
1. Once again, get your materials ready according to the drawing. This time you'll need to cut a 45 degree bevel, so use a reliable measuring tool to set your table saw or band saw to 45 degrees, then run your board through the saw.
2. Once all the parts are cut to size, check the fit and do any necessary sanding. When you're happy with the fit, glue the first set of beveled strips to the perimeter of the 1/8" piece of plywood. Tape the outside and clamp between two boards.
3. Using the finished half, sand the remaining 1/2" strips until they fit flush with the 45 degree faces touching. Then, glue these to the other 1/8" piece of plywood.
4. Cut some 1/4" strips to fit as shelves, and glue and clamp them in place.
5. Line up a set of magnets around the perimeter of the strips so that the magnets will hold the compartment shut. Use the 3/8" drill bit to set the magnets below the surface of the 45 degree face and seal with a dowel.
6. Continue to check the fit and make any necessary adjustments. Like I said, this was the hardest for me and could still use a little work.
Step 6: Style D (Bottom Compartment)
Style D will be the bottom compartment, and is probably the easiest to make.
1. Prep materials according to the drawing.
2. In one of the shorter, 1/2" strips, drill a centered 3/8" hole, and cut out the edge not being glued so that it is open, like a mousehole.
3. Glue the 1/2" strips that make up the frame to one of the 1/8" boards. Clamp and let this dry for about 20 minutes.
4. Use the 1/8" strips form the inside of the box. Start by gluing the four 1/8" strips together lightly. Then, with the strips still in place in the box, press the second 1/8" board onto the strips, and press down firmly for about 30 seconds. This should make the glue tacky enough that when you lift the 1/8" board, it will pick up the strips without them moving. Now clamp between two boards and let the glue dry completely.
5. Using the 3/8" drill bit, continue the hole from the 1/2" board through the 1/8" board, and use a saw to open it on the non-glued edge.
Step 7: "Key"chain
This keychain is the key (thus, "key"chain) to opening compartment Style A, which has two magnets embedded in the drawer face.
1. For this keychain, you'll need a spare key ring with a ball at one end, a scrap of walnut or another hardwood, and a 1.5" long, 1/2" diameter threaded nipple with a cap.
2. Start by trimming your scrap of wood. You should end up with a 5" long piece measuring 3/4" by 5/8". Cut this in half so that you have two 2.5" long pieces.
3. Take one of the pieces, and drill two 3/8" holes, 1 inch apart (or however far apart the magnets in the drawer are), just enough to accommodate the magnets just below the surface.
4. Mark with a pencil where the magnets are, then glue the other 2.5" long piece to cover the magnets. Clamp and let the glue dry.
5. Now, trim the whole block to 3/4" by 3/4", so that the magnets are just below the surface of the block. This means that you'll be cutting all but 1/8" of the second block that was glued on.
6. Cut the 3/4" by 3/4" block down to 2" long, and cut the last 1/2'" off to make a cap.
7. Drill a pilot hole, about 1/8" in diameter, through the center of both the body and the cap, the long way, just far enough that it doesn't go through the far end.
8. In the main body of the keychain, drill a 3/8" hole to accommodate the 1/4" threaded nipple. If the fit is right, you should be able to screw it into the hole with a pliers.
9. Drill a 1/2" hole in the cap to accommodate the threaded metal cap. Drill only as deep as you need so the metal cap sits flush. Tap the cap into place with a little glue.
10. The other side of the cap should still have an 1/8" hole in it. If you're lucky like I was, this is the perfect fit for your keyring. Lightly tap the ball into the hole.
11. Use sandpaper on a flat surface to square the corners and make the whole thing nice and smooth.
Step 8: Secret Stash Bulb
Just for fun, I decided to make a secret stash light bulb just to keep the theme going. I wouldn't recommend actually stashing anything inside the bulb in case the lamp was plugged in. If you are going to use the bulb, I'd disconnect the electric so there are no accidents.
1. All you'll need for this secret stash bulb is a white candelabra light bulb and a bit of bright spraypaint.
2. With a leather glove, hold the lightbulb in one hand and use a needle nose pliers to break the purple glass, and pull it out piece by piece. You might need to continue to break the glass with the pliers until you can get it all out. I'd also recommend wearing a dust mask and glasses for this part. You never know.
3. Use a paper clip to form a small hook to pull the filament out.
4. Sand the edges of the screw in base smooth.
5. Spray the end of the bulb with some red paint to remind you that it's not a working bulb.
Step 9: Putting It All Together
Ok, at this point we've made four sides out of plywood, a keychain, and a secret stash lightbulb. Now we'll put it all together into a lamp.
1. Here's where you'll need the copper sheet, candelabra lamp kit, and edison bulb.
2. Cut the copper sheet to a 4" by 5" rectangle so that it fits on the bottom compartment. Use a file to smooth the edges.
3. Use Gorilla Glue to fix the copper sheet in place, and clamp it until the glue dries.
4. Use a ruler to mark the center of the sheet, and drill a small pilot hole through both the copper and plywood lid of the compartment. Then, use a 5/8" bit to make the hole large enough to accommodate the socket.
5. Thread the socket through the back of the compartment where the holes are drilled.
6. Now, take your four finished sides, and use wood glue to secure them all together. Check for square, then clamp.
7. Fill any gaps with wood filler and use sandpaper to clean up the edges.
Step 10: Done!
And that's it! Time to hide away some stuff. Like I said in the beginning, the concept can be taken anywhere. This particular lamp will hold small treasures like candy and stickers in addition to things like cash or hard drives. Put it on the shelf, install the Edison Bulb, and enjoy. Thanks!