Howdy. When I make a guitar, I make a photographic record of my progress, and when I reach the end, I pile them all together and make a slide show, video style. The customer likes to have a record of how his or her guitar was put together. It takes a bit of remembering to take the shots, but it is well worth the effort. Having good lighting is not always possible, but usually it works out ok. I often take a few extra snaps to have a selection. Sometimes one forgets how a certain task was done. Well, now all you have to do is breeze through the video to jog your memory.
Once I have cut out the soundhole , I quickly grab the template and place it on the soundboard and trace around the outline. Flip it over and do the opposite side. Now it is time to mark out the braces and the bridge plate. You need to mark where the bridge and saddle sit on the other side of the board. It is not necessary to draw a great big full size plan of the guitar, but just a single line on a long piece of cardboard. Measure along from where the nut would be at one end the scale length of the guitar. If your scale length is 25.25″, then place a mark at that point. Measure the halfway point and that will be the 12th fret position. As we are building a 14 fret to the body guitar, then we need to know the distance from the 12th fret to the 14th fret. A little bit of maths is required here. If you divide the scale length of 25.25″ by 17.817, then your answer will be the first fret measurement. Take the first fret measurement away from 25.25″ to get the new distance that you have to divide by 17.817. Your distances will keep getting smaller and you will keep going until you get 21 or 22 fret spacings. You really only need to mark out frets 12,13,14, so that you can determine where the body join is. A little bit of string compensation will be required to get the saddle in the right place, so add 3mm to the string length on the single line drawing you are doing. When you have a fret template at your disposal, it is easy to mark out the 14th fret position in one go on your single line drawing. Take your single line drawing and place the 14th fret position over the body join area, and then mark off where the saddle position falls on your soundboard. Transfer this point to the opposite side of the board (the bracing side). Now you can see where the bridge plate will sit, and how the 2 main soundboard braces will sit. A really nice bracing template can be bought from Stewmac, where it is a piece of cake to transfer all these bracing locations to your blank. Well, I’m still dreaming about the day I will get one. You have the chance here in your design to play with the angle that the main braces subtend at the X intersection. You don’t want the braces to be too close to the soundhole edge or too far from the soundhole edge. When you learn to build a guitar, these are factors that will keep cropping up.
Using a pattern to mark the outline
It can be quite a task making your first guitar. I found that the more books I read, the easier it became to get my head around all the different processes. To this day, I still run out of time because I forget some of the processes that have to be done, and I run overtime. I will now begin to show the process of building an acoustic dreadnaught guitar.
The first is wood selection, so you have to first decide which woods you will use. Not only will the type of wood be a factor, but the colour scheme of the woods also comes into play. To see a selection of back/side wood and top wood, go to www.desanthony.com/workshop and woods.These are the main timbers that I use, and I try to use wood that is available within Queensland. Soundboard woods( Spruce and Western red cedar), are not available in Qld., but other woods like King Billy pine, Bunya pine, Hoop pine are available in Qld. Importing spruce is not all that expensive if you are prepared to use a lower grade. Soundboards are available from www.stewmac.com and www.alliedluthierie.com and The Luthiers Mercantile. You will be pleasantly surprised at the quality of the lower grade board.These pre-sized boards (thicknessed to 3mm) certainly save you a lot of work. Otherwise you will have to bandsaw the soundboard from a block of spruce, if you were able to buy it like that.
The photo above shows a spruce top that has already had its halves joined to form a bookmatched top. A plywood pattern is sitting on the surface, ready to have its outline drawn onto the spruce. Assuming you have a pre-bought top, you will need to plane and sand the two edges that will be glued together. I use spring clamps at either end to line up the edges, then I put the clamped pieces into the vice and plane and or sand the edge surfaces. After you take the two boards out and line them up facing a bright light, you will see where the light will shine through if your initial sanding wasn’t thorough enough.Repeat the process until no light shines through your join.Careful not to be too gung ho and reduce your overall width of the top, so your pattern overlaps the outer edge.Gluing up these two boards used to be stressful procedure, but for many years now i have used just two lightweight aluminium sash clamps that only cost $15 each, and they sit under the boards at either end.A spring clamp holds the boards together at each end as well at the middle, and a long 500mm klempsia clamp straddles the boards at the mid point.The sash clamps don’t need to exert much pressure, just enough to see the glue squeeze out. Allow to dry overnight before marking out your pattern.