Intro: "Cartoon-style" Inlay on an Acoustic Guitar
This Instructable describes how to do cartoon-style inlay on an existing acoustic guitar. Ever since I first saw a laser cutter, I have wanted to try using it to decorate a guitar. Tech Shop gave me that opportunity. You can do this type of work on your instrument, too. A laser cutter helps a lot, but is not essential, as people have been cutting wood veneer for inlay for centuries. The "cartoon style" approach is good for your first attempt, as it is a lot more forgiving than traditional inlay and marquetry. What makes it "cartoon-style"? Simply that the veneer pieces are surrounded by black lines like they are in a cartoon. That way, the pieces don't have to be cut with the precision used in traditional marquetry.
Here's what you'll need:
A guitar. This instructable uses an acoustic, which is generally trickier than an electric (my first go-round was actually a Telecaster, but I didn't document the steps on that one). I would strongly recommend that you use a cheap guitar that won't elicit a suicide attempt if things go south--for the love of God, don't go to town on your Collings or your Clapton-signature Martin with power tools...
The guitar I used is a Takamine G-series 12 string, which was obtained off Craigslist. It played and sounded pretty good for a low-end 12-string, but there are two big downsides to cheap guitars like this. First, low-end guitars are invariably finished with a tough poly finish that is good for banging around but a nightmare to remove. Second, low-end acoustics are invariably made of plywood, so you have to be really careful not to sand through the pretty surface wood into the ugly ply.
Step 1: What You'll Need...
In addition to the guitar you will need:
1) A computer with scanner and graphics software. I used Photoshop (at home) and Corel Draw (at Tech Shop).
2) Lots of fine-grade sandpaper. Mine was primarily orbital sander paper between 150 and 320 grit.
3) A dremel tool or router with a plunge bit. I used a cordless dremel.
4) Wood veneer and a means of cutting it. Boxes of small veneer can be had quite reasonably on eBay.
5) Good quality wood glue. I use Titebond.
6) Epoxy and colorant. I use 30 minute epoxy to give myself longer to work, and mix in a dab of black acrylic paint for color.
7) Refinishing supplies. I happen to love Birchwood-Casey's Tru-Oil (a gunstock refinishing kit) for guitar refinishing, but spray lacquer or wipe-on poly can also be used. You'll also need 0000 steel wool to smooth the finish.
Things that are not essential but come in very handy:
An orbital sander. Actually, this is almost a necessity.
A dust mask. You do not want to inhale this stuff.
A shop vac. To dispose of the dust.
A router attachment for the dremel tool. Again, this is almost a necessity to control the depth of cut unless you have the steadiness and precision of a brain surgeon.
A laser cutter (Hello, Tech Shop!).
Step 2: (Really Step 1): Produce the Artwork on the Computer and Cut the Veneer
First things first--decide on your design. I used a character based on the work of Vaughn Bodé, the brilliant underground cartoonist from the sixties and seventies. I drew the character in bold black marker on a piece of paper, then scanned it into the computer. I then used the editing tools and trace functions to isolate and outline the pieces--in other words, each bold marker line became two lines (one for each side) in the computer. Take a look at the picture and you'll see what I mean.
I then used the design to cut the outline out of a number of different veneer sheets on the Trotec laser at Tech Shop. I used about four different types of wood. If you don't have access to a laser, you can use an X-acto knife, but watch your fingers and use a sharp blade or you'll shred the veneer, which will want to break along the grain with almost no provocation.
Once I had cut the design out of a number of different woods, I assembled the pieces mix 'n' match to get the look I wanted. I then attached then to a piece of paper with a small dab from a glue stick to keep them organized.
By the way, I don't recommend that last step--they were a gold-plated bear to get back off without breaking.
Step 3: (Really Step 2): Strip the Guitar
First, remove all the hardware from the guitar and put it aside. Now comes the tedious, scary part. Using sandpaper ranging from 150 to 320 grit and an orbital sander, carefully strip the poly finish from the sides and back of the guitar. Go slow and keep the sander level or you could eat through to decorative veneer into ugly ply.
Believe me, I know from whence I speak. I knew the back was ply but stupidly assumed to front was solid spruce and didn't take as much care stripping it. Surprise!
Wear a dust mask and use your shop vac frequently. Take your time.
If you are working on a solid-body electric, you can save a lot of time by using a heat gun and a spatula to strip the finish. Unfortunately, that heat will make an acoustic guitar come apart at the seams (and possibly de-laminate), so unless you want to reassemble the guitar body I don't recommend it.
Step 4: (Really Step 3): Rout the Pockets and Glue Down the Veneer
Once the body is stripped, wipe it down to remove the dust and transfer the design to the back. I just printed a copy of the design and cut it out, then traced around it in pencil.
Using a dremel in a router stand and a 1/4 inch plunge router bit, carefully route out a cavity that is not quite as thick as the veneer. Try and make the bottom as smooth as possible.
Now, using wood glue, remove the design piece by piece and glue it in the cavity using wood glue or veneer glue. I found that the best way was to glue a few pieces, then cover the design with plastic and weight it with about 25 lbs. of books for about ten minutes to allow the glue to set. After you have all the pieces set, let it cure overnight under weight.
I might be wrong, but I would not trust an acoustic guitar body to stand up to the 15+ pounds per square inch produced by a vacuum press.
Although not absolutely necessary, I stained the body before placing the pieces.
Step 5: (Really Step 4):Epoxy and Sand the Inlay
To create the black lines, mix some color into a dollop of clear epoxy. I use 30 minute epoxy so I don't have to work so fast mixing the color and spreading it on the inlay. Allow it to dry overnight. To keep the color from penetrating into the surrounding wood, I went over the inlay and the pocket with a thin wiped coat of tru-oil and allowed it to dry.
The next day, use the orbital sander to sand the design flush with the surface. If your depths were OK, this will remove the epoxy from everything but the lines. It will also remove the upper part of the inlay wood with the tru-oil on it, leaving bare inlay wood.
After the sanding is complete, use a brush to carefully stain the surrounding wood that was stripped during sanding of the epoxy. I avoided staining the inlay, but feel free to march to your own drummer.
Step 6: (Really Step 5): Finish
Now you can finish the guitar back as a single piece. Tru-oil is the easiest option I have found. Wipe on a thin coat. Allow to dry. Lightly buff with 0000 steel wool. Wipe with clean cloth. Repeat as desired to achieve the finish you want.
The other picture is the inlay from the tele.