What you will need:
-A guitar which you no longer use
-A saw (I used a hand saw, but a jigsaw will work better)
-Screws (40mm recommended)
-wood (for shelves)
Step 1: Remove the Strings
Unwind and loosen the guitar strings as much as possible before cutting with pliers so that they don't spring off the guitar (this may hurt if the strings are kept tight). Then use a pair of pliers (any kind will do) to snap off the end of the strings from the saddle. On the head of the guitar, the strings can be unwounded and pulled out of the pegs by hand.
Step 2: Cut Open the Guitar
Cut along the black edge on the side of the guitar using the hand saw. If you are using a jigsaw, mark a line about half an inch onto the face of the guitar (front), and cut along that. I would recommend using a clamp to hold the guitar in place.
Note: Be patient with it. It will take some time, but if you rush, you may injure yourself.
Step 3: Clean Up the Edges
Use sand paper to smooth down the edges of what you have just cut so that you don't get any splinters when using the shelf. Then use a vacuum to get rid of any small pieces of wood and sawdust from inside the hollow body.
Step 4: Measure and Cut Your Shelves
Use measuring tape to see how big you want the shelves to be. I wanted them to slot in fairly tightly against the body, so the dimensions I used are as follows:
37.5cm length X 8.5 cm width for the large shelf
23.5cm length X 8.5 cm width for the small shelf
You can check these dimensions once you have cut your pieces by slotting them into the guitar, as the size of guitars vary.
Step 5: Fit Your Shelves
Use a drill to make holes in the sides of the guitar as well as into the shelves. It is better to pre-drill before adding the screws. Then fit in the screws until you can't drill anymore. Put two screws in both sides of each shelf.
Note: The screws will very slightly stick out from the body of the guitar. Don't force the screws any further because the wood of the guitar is very soft, so it may crack if you do so.
[The reason there are three arms is because I needed help keeping the shelves in position.]
Step 6: Paint Your Shelves (optional)
Add a layer of paint to add some character to your shelves, and make it look a bit nicer (in my opinion). By all means, you can leave it as it is with the wood showing, but any colour paint will do (depends on whatever you prefer). Two or three coats should cover the base. I used 'decopatch acrylic paint', so there is quite a smooth finish.
Step 7: You're All Done!
I decided to keep the front of the guitar and left it to rest against the body (because I think it looks cool :)). Then find a suitable place for it and add whatever objects you want onto it. I sat mine on the floor against my dressing table, but you can mount it on the wall by using screws or even a wall guitar holder.
It is also optional to polish the entire body of the guitar- normal wood polish can be used, or even nail polish remover! You can customise this project however you wish- add extra or less shelves or even add hinges to the face of the guitar so it becomes like a little cupboard.
Voila! Enjoy your super cool guitar shelf!