Well, I never did get to that other post for Woodworkers Safety Week 2008 but, I think that if you took the time to read some of the blogs you saw enough of the menagerie of safety devices available to help keep you safe in the workshop. At some point I can do a post about some of the more unique things I have done in my shop for safety’s sake. Now, on to the matter at hand…
When we last left the Dreadnaught Guitar project, I had completed all of the bracing for the top. The next step in the project is to glue the top and the back to the sides. However, before this can be done, the kerfed linings must be notched for the braces and the braces must be trimmed to intersect with the linings appropriately.
In the picture, you can see the guitar sides (still in the waist clamp) mounted in the vice on my workbench. I clamped the top to the sides temporarily in order to mark where the top braces intersect the sides. This was important step which required some careful measuring and squaring. Even though there is an inner mold supporting the sides, there is still some play in them. When clamping the top on, I made sure that the neck block area was as square as possible to the guitar top. This is important because it will minimize adjustments to the neck when it gets attached later (I’ll need to repeat this step when I actually glue the top, as well) It was also imperative that the neck block be located at 3 15/16″ from the sound hole and that the tail block be 20″ from the neck block. Once all of this was set I clamped the top to the sides.
With the top clamped in place I marked the positions of all of the braces where they intersected the sides. I made sure to capture than angles that the braces made as they crossed the sides. After this was done, it was time to mark the braces along the sides to indicate where they would need to be trimmed to. I did this while the top was still clamped in place so that I would not have to repeat the placement again later.
Now it was time to cut the notches in the kerfed linings to receive the braces. I’ve seen this done two ways – one way is to cut all the way through the sides where the braces intersect, the other is to cut only through the kerfed linings to create a little “pocket” for the ends of the braces to be glued into. I chose the latter. It just seems to be a more refined way to do this. To do this, I used a knife along the marked lines at an angle to create a kerf on each side of each notch and then carefully removed the waste with a sharp chisel. It was important to only recess these notches down to the height of the braces (about .100″). They also had to be angled slightly to match the angle on the ends of the braces.
With the notches cut in the linings, I moved on to the top to trim the braces. Because my previous marks were made on the outside edge of the sides, I moved in toward the center of the top a distance equal to the thickness of the sides from my marked locations. I made a narrow saw kerf at that location and then removed the ends of the braces with a chisel. I also reshaped the ends of the braces to be sure that they finished at about .100″.
Next, it will be time to glue the top to the sides. However, before that can be done I need to make some special clamps to help with the process. Of course, once that is done, I will have to repeat this process for the back.