Getting back to rosettes

As I was saying, the first step to successful rosette making is the same with every step of guitar building - plan and take your time.  You can go back to arguing the chicken or the egg all you want, but it really doesn't matter; if you already have your materials in mind, think of what design might work best with those materials.  If on the only hand, like me, you have a design in mind, put it down on paper then go find the materials to match.

I, for some unknown reason, have a fascination - or perhaps a fixation - with spalted and ambrosia maple; I can't help it, to me it's God's gift to luthier-kind.  It must have been ingrained in my psyche after all those hours of continuous searching on the internet for the most distinctive acoustic guitar traits.  I think my record was 5 hours one late night until my eyes glazed over, rolled back into my head, and my wife found me the next morning keeled off my chair in a puddle of drool, twitching and muttering spalted maple, spalted maple... over and over again in my sleep.

Needless to say, the counseling helped but did not cure me of my spalted maple craze.  So getting back to the real story, I looked online at a few places, finally found a mill in Maine that sold some decent sets of spalted maple, bought a couple sets and had the mill resaw the best set into 1/4 inch plates that could be easily utilized in the shallow rosette channel.  Once I had the materials, my inspiration, in hand I began to draw a 1:1 mock-up of the rosette on paper.

I started by tracing the soundhole outline in the center, then played around with varying rosette widths and compositions.  I ended up deciding to keep it simple on the first go around - center spalted maple ring about 1/2" or 5/8" in width surrounded by thin 3/16" curly bubinga border rings.

Next I carefully drew the desired circles for each wood plate using a vintage compass.  The bubinga was easier because, after jointing and joining two smaller book matched plates together, I could simple scribe the inner and outer rings I wanted and cut them out from the same plate.  Word to the wise, when doing something similar, start from the outer most edge and work your way in on subsequently smaller diameters.  Otherwise you'll find you need to do some special engineering if you start from the inside and work out!

The spalted maple pieces were much more tricky.  For the center ring, I wanted to get a lot of figuring in that little space.  You're liable to win the lottery before you find the perfect piece of spalted maple for such a task, so what I've seen done on a number of examples, is to cut out several smaller sections from highly figured areas in the proper curvature, then joint them together.  You can make it obvious or subtle, either way works.  I can't say which exactly mine ended up being but it's probably on the subtle side.

To do all the cutting I used a StewMac Foredom tool jig used to make precision small circular cuts.  It worked well once I figured out how tight I needed to keep all of the nuts and screws on the thing when cutting through hardwood.  All the vibration would loosen everything up until I was completely out of alignment.  Good thing I learned all this on practice pieces, something I highly recommend you do for rosette making.

Once I had all the pieces routed with the Foredom jig and a down-cut spiral bit, it was time to rout the lay-up board which would be used to fine tune the pieces in preparation for the harrowing process of routing your precious soundboard.  Unfortunately, I still haven't gotten to the bottom of finishing off the rosette.  One more post ought to do it.  I apologize for the lack of pictures, but I think all of the pictures I have can be seen on the slide show below which links to my Flikr site.  I'll be sure to put some nice shots in my last post on completing the rosette.  Until then!