For a while I have been wanting to take an acoustic guitar and do some Frankenstein-like modifications to it. Towards that end, I have been shopping around town for a really cheap acoustic guitar that I wouldn't mind ripping apart. Unfortunately, all of the cheap one's that I found were really poor sounding. I was just about resigned to throw down a hundred and change on a largely mediocre guitar when I had an epiphany. Why not at least try to repair the cracked headstock on my old acoustic guitar? I mean, it must have been sitting in my closet for the last two years for some purpose!
So, I set forth to repair the guitar the only way I knew how (gluing and clamping) and ended up doing a much larger repair job with it. The results ended up being both functional and aesthetically pleasing and will now guide the direction of the rest of the rebuild.
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Step 1: Don't Lend Your Guitar to Bilal!
As the title of this step explains, the first step in guitar head repair is prevention. The best way to prevent needing the repair the head of your guitar after it has been cracked in half is to not crack it in half in the first place. This can be accomplished by not lending your guitar to Bilal.
As you can see below, there is Bilal with an unsavory robot and my guitar. Now, I am not going to jump to any conclusions from this picture about the trustworthiness of robots, but it would be fair to say that this picture, at the very least, throws into doubt the trustworthiness of Bilal. How can you trust a man that consorts with robots in such a friendly manner? I hear that is how replicants are made!
In short, do not lend your guitar to Bilal.
Step 2: Go Get Stuff
You will need:
An acoustic guitar with a cracked headstock
1/8" x 12" x 12" translucent red acrylic
12" x 12" copper foil
1/2" wood screws
2" bolts and corresponding nuts
Dry erase markers
Heavy duty spray mount
Various shop tools (and possibly a laser cutter)
Step 3: Glue and Clamp
Apply a thin coat of wood glue to the cracked joint and put the joint back together. Clean up any excess glue. Then use a thin sheet of cork to protect the guitar from being dented by the clamps. Wait overnight for it all to set and then you should be done.
What actually happened:
I applied too much glue. It started to seep into the holes for the front two tuning machines. I had to quickly remove and wash them. I didn't have time to clean off the glue properly as it was everywhere and starting to set. I hastily clamped it in place and let is set overnight. In the morning, I concluded that albeit, it looked ugly, I had in fact glued it as planned. Unfortunately, after applying a little bit of force to the head, I concluded this wasn't going to hold and needed to be reinforced. Move on to Plan B (step 4).
Step 4: Cut Acrylic
Download the attached file and use it as a guide to cut it out of a sheet of 1/8" translucent red acrylic.
The idea here is to make two pieces of acrylic which will sandwich the headstock and be bolted together, hence acting as a sort of 'splint' to keep the head from cracking in half again.
Step 5: Cut Flames
Track the outline of the acrylic headstock bracket onto a sheet of copper foil and then cut out the shape.
Next draw awesome flames with the copper foil and cut that out as well.
Finally, you can hammer the copper flat with a hammer. If you hammer both sides it will prevent curling.
Step 6: Trace Holes
The original plan was to mount the copper flames atop the red acrylic, but when I put the copper behind the acrylic to trace circles for cutting holes, I was pleasantly surprised to find this very aesthetically pleasing, thus I resolved to mount the flames in back.
Anyhow, in case you haven't gathered, you should trace circles for mounting holes.
Step 7: Cut Holes
Cut holes in the copper foil where you have just traced them.
Step 8: Make More Flames
After making the first set of flames, I decided that it would still probably look pretty good to have a smaller set of copper flames on top.
As such, I have produced a second smaller set of flames by the same method as the first.
Step 9: Apply Epoxy
Epoxy the crack for good measure. Try to work it into any gaps that may still remain. Once it is set sand and/or file it even with the guitar. Wait thirty minutes or so for it to dry.
Step 10: Attach the Top Flames
Trace cut holes in the top flame, you will use these to align it after you glue it to the acrylic.
Spray an even coat of spray mount on the back side of the flames. Press that firmly to the acrylic. You can get even pressure by pushing the acrylic down onto the flames on a sheet of wax paper.
Wait a few minutes for it to dry and then punch and/or cut out holes in the copper flames.
Lastly, clean off any stray stickiness with a towel coated in acetone.
Step 11: Attach
Remove all of the nuts from the tuning machines.
Sandwich the bottom layer of copper and the top layer of acrylic onto the headstock.
Reapply all of the nuts and use a wrench to tighten them back into place.
Step 12: Reinforce
Place the weird H-shaped piece of acrylic on the backside of the headstock and use the lower holes as guides to drill all the way through (or whichever holes would be necessary for maximum strength).
Clamp everything together with nuts and bolts. Insert small wood screw into any unused holes in the back to better hold that piece in place.
Step 13: Shape the Headstock
Use a heat gun to shape the acrylic bracket behind the headstock to better follow the curve of the neck.
Trim the bolts to size with a Dremel and also file down any sharp unwanted edges.
You should now be ready to string it up. I didn't do this yet, however, because I still want to do some wicked-awesome modifications.