Build Your First Guitar
So you want to build a guitar? I am going to tell you that building a guitar is more difficult than some projects but with some simple tools and a little skill you can surprise yourself. First off let's look at a few things that you will need to know.
You can build a kit, or scratch build. I suggest that you start with a kit. The parts are closer to finish and you don't have as much technical work to do. If I may suggest, a book on the subject is a good thing to have. I don't recommend to get a lot of books. Too much info can confuse you so try and keep it simple. Once you get some experience then expand your horizons.
You will need a good selection of clamps. I use epoxy to set the truss rod. White Elmer's glue for anything that may need to removed. This includes the fingerboard and bridge, also the neck joint. Yellow glue (Tite Bond) for most everything else. If you are using plastic binding use Duco Cement for that. Super glue is fine on pearl but white glues also work great there. For tools you should have at least a small laminate trim router. A good SHARP chisel and again CLAMPS.
Building is in three topics. The box or body. Most kits have a pre-contoured set of sides. The flattest side is the top and the rounded side is the back. Mark this with chalk or tape. You glue in the blocks and set in the kerfing (this adds glue surface for top and back joining). I use a mold, but regardless of method you use this is where accuracy counts to maintain the neck angle. Once the guitar body shape is set you attach the top and back. The top gets braced as does the back. In steel string instruments the X bracing is used. In Classical guitars the bracing is lattice or Fan.
The top is glued up then the neck is pre-fit. I like to use a rasp to get the neck close. Neck setting will denote the action of the guitar so take your time. Whether you use a dovetail joint or 'bolt on' the fit is critical. You need to watch center line of neck to body, parallel to top and neck angle. This is the line of the neck to the saddle. You want about one-eighth to three-sixteenth inch at the saddle area off a raw neck. I mean if you shoot a line off the top to the neck where the fingerboard will be attached, the height of that line at the point of the saddle (your scale length) should be 1/8" to 3/16". When you complete the neck and final fit this should get you very close. The neck is pre-fit. This is the beginning of the heart of the guitar. Take your time and when you are happy you can start neck assembly. I epoxy the truss rod in first. Follow the kit directions. You may have to cut the top for the truss rod to drop in so don't fret. I set the frets in the fingerboard before I attach it to the neck. Cut the frets a little longer than you need. I use water in the slots and bang them in with a brass hammer. Be sure to pre-bend the frets a little. After the frets are in place, glue the fingerboard in place. Most kits have a pair of roll pins to locate the fretboard to where it needs to be. Here is where I use white glue. Also in Martin kits there is a black piece of fiber strip that gets set between the truss rod and the board. After the glue dries file the fret ends and use super glue for this step. Sand the edges and drop super glue in the slot edges. This may take 2 or 3 applications, but it closes up the gaps. A safe edged file is used to dress the ends of the frets.
Sand fill and final finish then you are ready to assemble the guitar. When the body is together it is time to finish. I use 120 grit paper. First I use naptha and wipe it clean. A light sanding of the 120 grit and it's time to seal coat. I use either shellac (clear) or vinyl sealer. After sealing I fill. I use Jasco brand filler and add Minwax dark walnut stain for rosewood and light walnut for mahogany. Follow the directions on the can. Scuff and seal again. Sand (220 grit) then start finishing. I use nitrocellulose lacquer. I will spray 6 coats with a 40 minute wait between coats. Let sit 3 days, sand 320 grit, and check for voids. I will use a model paint brush and fill them in. Sand and check to see they are filled. Spray 3-4 coats with the 40 minute wait and let sit for 3 days. Wet sand (440 - 600 - 800 - 1000- 1500) to polishing paper. This you get at most auto paint supplies store. When you are happy with the finish use marquises swirl remover for final shine and set in neck. Add bridge and strings and your guitar is completed.