How to do a 3D inlay on guitars
by
Brian Calvert

Before we get started let me just say if you have never attempted an inlay before, practice a few times using a spare piece of wood such as a 2x4, this particular method use's a clear acrylic sheet for the main material on top which can be purchased in 8"x10" sheets for under $4 and will render enough material to do this several times over so take your time and practice. My method may not be the same as others and your results may very but it works for me!

You will also need to have all of the frets off of your board unless you plan on spending the next year or so doing fine detail sanding between frets, I used a 16" pre-radius ebony board for this tutorial and did not fine sand it till the end just encase I made any small marks along the way (accident's can happen). You can either start with your fret board mounted to the neck or not, as you will see I choose to attach this one part way thorough.
The first thing I did to start this tutorial off of course was a lot of research but I also wanted to achieve my goal in the fastest way possible so I drilled a 1/4" hole in a 1/2" thick board and cut a slot going to the hole from the side to make a jig for cutting on my table top jig saw.
  
 
Of course to hold it in place I used some of the new spring clamps you can pick up at just about any hardware store these days, those things are great!
OK let's get started on the actual work, first of all since this is a tutorial about doing a 3D inlay it will involve using a flat insert such as the one I've made out of vinyl decal material pictured on the right and inlaying it under a clear piece of acrylic plastic. I'm using the 3/32" thick type found in the local Lowes hardware. First I laid the insert on top then I scored a line along every edge of my insert to make a clean very tight drawing on the acrylic sheet.
 
 
Next I cut out each of the individual pieces using my table top jig saw on the lowest setting which is 400. At this speed it doesn't melt or weld the acrylic back together behind the cut. Just be sure to take your time and also blow away the dust often so you can follow your line. I left the backing on the bottom side of the acrylic to protect it till it is ready to go into the fret board.
Inspect each piece as you get them cut for closeness to your score line. If a piece isn't cut properly you can always run it up and down a flat bladed file, this also helps to smooth out any ragged edge's you may encounter
  
 
Next lay each of your pieces on the fret board where you would like them to be mounted and score a line around each one. When positioning them you might want to whip out your scale and measure the left and right space as well as the space between the frets so they are centered unless of course your planing something wild or different.
As you can see on the photo to the right sometimes when you think you have it right you end up laying it back down and finding out your hand was at an angle causing a smaller mark than you really need so be sure to go back and check each one over again since this will be the final time before your actually cutting into the wood.
  
 

Now start out using a very fine cutting tip on your Dremel, yes the inside of the outside line is a freehand cut, just take your time and stay inside the score marks. No need to rush and trust me unless you develop some sort of system for effectively using a router attachment for this part and test it out on a scrap board (many times, practice is wise), your going to have to do this part the old fashioned way.

PS If you couldn't stay in the lines with Crayon's as a child now is not a good time to try this on your actual fret board at home =o)
After you have finished freehand cutting the inside out the outside edge on each one switch the bit in your Dremel to a larger actual router bit and attach your router base. Adjust the height to about 85-95% of the depth of the acrylic so when your finished the piece's will still be sticking out of your board all across the top.
  
 
Of course be very careful as you do this step and constantly blow away any buildup of dust that impairs your vision.
After you have cleaned up what you could in the middle it is time to switch back to your original tiny cutting tip and discard the router base again.  
  Take your time and clean up the inside of all of your edge's by underscoring them with this bit, for the tight corners you couldn't reach with the general router bit use the tip to drill down under each one
Then take a new razor blade and slowly cut away the excess off the top that was to thin for the Dremel bit's. This will help give you nice tight corners.  
  Test fit each of your acrylic inserts into the cavity's as you move along . If they do not go in easy take them back out and observe where they are binding then go in and route away that area. Each piece should be able to go in without and force.
As you can see by the picture on the right each piece should not only fit easily but should also be visible above the fret board all the way across.
  
 
Time to grab your inserts and make sure each of them fit easily into the routes now. If they don't fit have a look to see if your going to have to adjust everything else or trim them (hopefully neither).
OK prep your board for some serious inlaying by making sure all of the dust and anything else that may have found it's way into the routes is blown away and they are totally clean.
  
 
I'm using a two part clear epoxy made especially for jewelry inlays, I'll start by mixing it up on a piece of aluminum foil since I don't trust the dust that can be created using plain paper. I also use toothpicks for my mixing and transfer tools (toothpicks are cheap).
I'm only mixing up about a 2" line of epoxy at a time since I don't want t to have a chance the set up before I have used most of my mixture as you can see with part A and Part B side by side on the right. As you mix the two parts together it is almost impossible to avoid little tiny bubbles of air forming in the mixture, we will discuss that on page two of this tutorial.
  
 
Now that you have your board cleaned up, your inserts easy to get to and the epoxy mixed it's time to get started. Swab up some of the epoxy and let it drip down into the cavity. You only need a tiny bit at this point so it can grab the insert your going to want under your acrylic piece so there is no need to go overboard at this point (A little dab will do ya).