So it has been a very long time! I think it is time for a much needed update. Lately I have been making guitar rosettes for some parlor guitars that I am building (trying to build, anyways).
I started by laying out my rosette design in photoshop. Then I drew up a simple template for a rosette cutting jig and printed it off.
Cut out a piece of 1/4″ black Acrylic on the bandsaw.
Next I drilled for the holes; this is a base that will be mounted on my router, so the holes are for the mounting screws.
I also took out a 1.5″ piece of aluminum rod (1/4″ diameter) and rounded the edges. Then I buffed it smooth on the buffing wheel.
Here is the completed router base assembly.
And voila – by drilling a hole in a baseboard, I can rotate the router around the pin (which is inserted in the baseboard hole). Using a 1/2″ router bit gives a perfect rosette channel.
Next up – time to make the rosette itself. I put a plastic cutting board through the planer to clean it up and flatten it, then cut out a square. I drilled a hole in the square (1/4″) in the middle, then used my router jig to cut a 3-4mm deep channel. This is the rosette mold. I also drilled some holes through the channel. This is to help remove the assembled rosette.
You can now use this mold to make any design of rosette you desire. You can add tiles, purflings of different colors, etc. I went for a BB/WW/BB/WW/BB/etc. motif. I soak b/w 1mm purfling in warm (not hot; you do not want the purfling layers to delaminate) water for 30 seconds to make it pliable, then layer them in the mold.
With the layering complete, it is time to glue up the rosette. I usually use thin CA glue; I used medium viscosity here because it was all I had on hand.
Spread the glue in with a piece of vulcanized fiber.
Once the glue has dried, I use a chisel to carefully remove the rosette from the mold. If you use lots of glue, sometimes the rosette is not easy to get out. You can push the flat end of a drill bit through the holes in the back of the mold to help force the rosette out of the channel if you are having trouble getting it out with a small chisel.
Once removed, you need to clean up the rosette edges by scraping any excess glue off. Then the rosette is finished.
It is important to test-fit the rosette before installation. Often some adjustment is needed to get it to fit the channel. The rosette should fit the channel; if it doesn’t, you’ll run into problems when you try to put it in with glue.
I used a piece of clear plexiglass with clamps to force the rosette down into the channel while gluing.
Use a scraper to flush the rosette with the soundboard.
And that’s it! This is a garbage soundboard (because of the separation that occurred at the top), but at least you can see how beautiful the rosette turned out.