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So this is my first "real" build after my foray into the land of make believe (as many of you likely think) when I modded a squire with my thermoformed acrylic face called the "Dichrocaster". I am teaming up with a very well respected local luthier to make my necks and bodies for the next few guitars, and want to make his job a bit easier considering my non-traditional approach. My big questions are about using a type of elliptical cross section to the body design for two reasons: Lessen the weight of the guitar to counter for the 1/4" acrylic face, and to add another dimension of light refraction off the quilted face. I really have not seen guitars with this type of slimmed down cross section, so there must be an obvious reason (I am only two months old in my guitar building obsession, so don't know a lot yet). The central part of the body will be 1-3/4" thick in wood section, 2" thick with the acrylic face, therefore the top and bottom edges and the horns will be significantly thinner. Horns may actually be delicately thin, like about 5/8" average, getting thicker closer to body center -need input for that reason. Wondering also if they make shallow switches to accomodate for a depth of only 1" or maybe less, unless I move the switch closer into the central thicker part of the body. See initial diagram, which is directed to my luthier, but you get the picture. Pic of Dichrocaster attached as well, so you understand the "acrylic face" concept. The other question is whether to mount the humbuckers to the wood body, and cut the acrylic out around them, or (easier way) to mount them to the acrylic face with swimming pool rout (which is essentially a giant pickguard, the way pups are mounted to strat PG's). Remember, I am real new to this, and don't always see the obvious.
Hola! I originally introduced the idea of a compound scarfing jig waaaay back in something like 2007-2008. A few people around ProjectGuitar.com have successfully used the idea, and a few people around the interwebs have taken it on also....some clearly took it directly (including images and zero credit) however convergent evolution means it would surface of itself at some point anyway. It's all cool. Rising tides floating all boats and that. The idea was based off the established idea of a router scarfing jig, but improved to allow for twisted headstocks and even string pull for multiscales that do not have a nut perpendicular to the centreline. Normally the treble side of a multiscale is pulled backwards, causing the headstock to "twist" clockwise as you sight towards it down the fingerboard. The higher the difference between the two outer scales, the larger the twist. This creates problems for necks with tilted headstocks as the scarf needs to incorporate a new compound tiltback angle. Thankfully, there is a simple solution to this which isn't much more difficult than the standard router scarfing jig. Firstly, let's look at the standard router scarfing jig: At their most basic, they consist of a box bounded by two guiding rails. On top of this rides a router with a wide sled which ensures it maintains contact over both rails. The neck and usually the piece being scarfed are cut at the same time. Depending on the final orientation of the scarf, one piece has the glue joint surface cut whilst the other has a facing surface finished: Pretty standard fare so far. To make a compound angle, the sleds are simply offset from each other. Rather than riding on the faces of the sidewalls the sled now runs on the edges; the inner wall on the furthest forward and the outer wall of the furthest back. The correct offset corresponds to a line drawn from each contact point on a flat plane: When glued up, both halves produce the expected compound scarf.
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 uses clear acrylic sheet for the main material on top which can be purchased in sheets for a few dollars 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 vary 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-radiused ebony board for this tutorial and did not fine sand it till the end just in case I made any small marks along the way (accidents 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 through. Firstly, I drilled a 1/4" hole in a 1/2" thick board and cut a slot to the hole from the side to make a jig for cutting on my table top jigsaw. To hold it in place I used some spring clamps you can pick up at just about any hardware store, 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 jigsaw on the lowest setting. 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's ready to go into the fretboard. 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 edges. Next lay each of your pieces on the fretboard and score a line around each one. When positioning them, measure the left and right space as well as the space between the frets to ensure that they're centred....unless of course you're planning something different! ....sometimes when you think you have it right you end up finding out the positioning wasn't that perfect. Be sure to go back and check each one over again since this will be the final time before cutting into the wood! I started out using a very fine cutting tip in a Dremel. Freehand works well if you take your time and stay inside the score marks. No need to rush this part and you can always practice on a scrap board (many times, practice is wise). PS. If you couldn't stay in the lines with crayons as a child now is not a good time to try this on your actual fret board! Get some practice in!! After you have finished the outside edges, switch the bit in your Dremel to a larger router bit and attach your router base. Adjust the depth of cut to about 85-95% of the depth of the acrylic so when you're finished the pieces 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 the middle it's time to switch back to your original tiny cutting tip to clean the edges up freehand. Take your time and clean up the inside of the edges by slightly undercutting them. For the tight corners the Dremel in the router base couldn't reach reliably, use the tip to tidy each one up. Take a new razor blade and clean up the corners until they are neat looking and tight. Keep test fitting each acrylic insert in the cavities as you go. If they don't go in easily, clean up the area where they're binding with the Dremel or the knife. Each piece should be able to go in neatly without force, and not sloppily. Each piece should not only fit easily but should also sit very slightly above the fret board. 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). Time to prep your board for some serious inlaying! Make sure all of the dust and any other junk that may have found its way into the routes is brushed out, blown away or otherwise removed; totally clean. I'm using a two part clear epoxy made especially for jewellery inlays. I start by mixing it up on a piece of clean aluminum foil since paper or card can contaminate the epoxy with dust and fibres. I use toothpicks for the mixing since they're cheap. I only mix up a small amount of epoxy at a time since I don't want to chance it starting to set up before I have used it all. Here you can see Part A and Part B side-by-side. As you mix the two parts together it is almost impossible to avoid little bubbles of air trapping in the mixture, but we'll discuss that a little later.... Now that you have your cleaned-up fretboard, your inserts easy to get to and the epoxy is mixed it's time to get started. Swab up some of the epoxy with a toothpick and drip it down into the cavity. You only need a tiny bit at this point so it can grab the insert you want under your acrylic piece. There's no need to go overboard at this point. A little dab will do ya. With a little dab of epoxy in the cavity drop in the insert make sure it lays flat. Take more of your epoxy and fill the cavity about 1/2 way making sure it spreads around evenly. If you encounter any bubbles in your mixture as you do this, poke them using a clean toothpick. You can push them away to the side but they'll escape when you place in the acrylic insert anyway. It doesn't hurt to get rid of as most of them as you can though. Now, set your insert down on top of the epoxy and gently press it into place. Let the epoxy ooze out along the edges. When you get to larger pieces it becomes difficult to chase air bubbles from underneath the acrylic . Instead, you can wipe a dab across the back of the acrylic and slide the insert on to it before forcing the bubbles out from the back with a toothpick. Gloves are advised because epoxy isn't good for your skin! Anyway. You can see that the bubbles show easily as you dab epoxy on top of the insert. Take your time and carefully tease any of them out as you work. The toothpicks are great for cleaning out any excess epoxy that manages to find its way into the fret slots. If you want, you can use masking tape or Teflon strips. One of the advantages of the particular epoxy I use (Epoxy 330) is that instead of waiting the normal dry time of 2-3 hours for it to set up an infrared heat lamp will harden it completely in 10 minutes. Don't do it too close otherwise the wood might crack! Your choice of risk. OK so now all of the inserts are in and the epoxy has cured, time for the inevitable sanding.... I started by using 80 grit sleeve to knock the top of the epoxy off. A flat bladed file is also a good option. Yes...it's a beautiful mess but it's my mess =o) Anyway the dust you create as you sand at this point should only be white in color, if you start to see anything else back off immediately as hitting the board at this stage is a very bad thing!! Now that the majority of the top has knocked down it's time to change to higher grits (120 to 220) and continue smoothing the area down. This is what it looks like once I finished using 220. The acrylic is fogged over but the magic will happen soon enough. Here is a side view. It's hard to see but the inlay is still sticking up slightly like a mini speed bump. I do not want it level just yet since the sandpaper of choice has been too large a grit and will cause permanent lines scored into the acrylic if I go any further. Time to switch over to radius block sanding. For this board I needed a 16" radius block. I started out with 320 grit, then each grit through to about 2000. If needed, final polishing can be done with micro mesh. It's useful to have compressed air available. Sand paper builds up with wood and epoxy dust quickly during the sanding process. You can also see the lines running up and down the length of the board from the radius milling machine slowly beginning to disappear. (this board was purchased online from LMII.com) As you change through the grits you will slowly start to see the top of the acrylic smooth up. If you're using an ebony board like this one you'll also see it polish itself up nice and shiny without the use of any oil =o) Fret markers 3 and 5 Fret markers 7 to 12 Fret markers 15 to 24 All finished and ready for the guitar!