Robbie visits Jeff Bamburg who briefly shows us how to create an arm bevel.
The arm bevel, also known as an armrest, is an option that not only looks good but makes the guitar more comfortable to play. However, this detail is better left to the professionals. It must be done properly to achieve the desired results. I have had many requests to do a Luthier Tips du Jour video on this topic. Therefore, I decided to visit Jeff Bamburg or Bamburg guitars. Not only is he an expert in executing the arm bevel, but he’s agreed to share the process with us.
The first step is to make a block that can be glued to the inside of the guitar in the location of the arm bevel. Jeff traces this outline onto a piece of paper, cuts it out slightly oversized, and then glues it to the piece of wood that will be used. This is then cut to shape on a bandsaw and then cleaned up on a sander. With the block in place, he then marks it for beveling on the inside and shapes this on a sander. The dimensions of this block depend on the design of your arm bevel. The layout of the bevel is critical so you don’t have any surprises later. Jeff uses a template to approximate the bevel dimensions. He likes to have 1/4″ of the block material for the soundboard to attach to. Once the layout and fit are correct, the piece is glued to the rims slightly proud, allowing for radiusing later.
After the box is closed, the binding and purfling channels are cut. Once this is done, Jeff places a template to use as a guide for cutting the purfling channel for the arm bevel on the soundboard. A router with a guide bushing and a perfect size cutter is used to make the cut. For the side purflings around the arm bevel, Jeff uses a flexible piece of plastic secured with double-sided tape as a template. Router and guide bushing setup is then used to cut this channel. Once the purfling channels around the soundboard, sides, and the arm bevel are cut, then Jeff installs the purflings on the guitar. He uses CA glue to do this.
The next step is to install the bindings and he uses the same CA gluing method for that.
The next thing to do is to begin shaping the arm bevel to the desired shape. Jeff begins the initial process with a block plane. He then attacks the bevel with a rasp. When he really wants to show it who’s boss, he brings out the big guns. He has at it with a sander like the one you see here. The purfling lines need to be flush with the top and sides so you know exactly how far to bring the arm bevel. You can then hand sand the bevel right up next to the purfling line on the top and the side. Take the time needed to make the edges of the bevel transition nicely into the binding and purfling, Also, make sure the bevel has a consistent uniform roundness to it. It should look similar to this when done shaping.
To make a veneer piece to cover the bevel, Jeff starts by placing a piece of paper over the bevel and lightly creasing it to mark the location. He then cuts this part out, slightly outside the line, and places it over the bevel area again, and does the same thing with the bevel part that meets the side. Double-sided tape is used to secure the template, while a flat pencil is used to mark the exact size needed for the veneer. The template is then removed and cut to the exact size. Some spray adhesive is used to now secure the template to the piece of veneer that will be used to cover the bevel. A knife can be used to cut out the shape. Glue is applied to the bevel area and then the veneer is attached. Tape is used to secure it as the glue dries. After the glue dries, spend some quality time scraping and sanding the edges of the veneer flush with the sides and top of the guitar.
If you did everything correctly, you should have something that looks like this. A beautiful and functional arm bevel on your guitar. Oh, I almost forgot to mention, you also have bragging rights. Not just anyone can execute an arm bevel like Jeff does.