I am starting to epoxy the falcate braces to the top. The layup is epoxy on the top, a wetted carbon fiber tow (3k, 5.7 0z), the brace and topped by another ribbon of carbon fiber. Having the CF under and over the brace puts the CF as far from the neutral axis of the brace as possible giving the most bang for the weight of CF.
The main falcate brace pass right between two of the bridge pin holes and over the bridge plate. Normally I use a chisel to cut a rebate into the brace to pass over bridge plate. This time though I decided to use my new mini router table Ken Picou's The Otter I bought at the Guild of American Luthiers auction [url]http://www.luthiersfriend.com/aOtter/Otter.html[/url] with a colt router and a 1/4" end mill.
I marked where the brace crossed the bridge plate and routed the rebate. This looks like it could be a useful tool.
I drilled bridge pin holes in my 32' radius dish to allow me to have some pins in the top to help with placement of the braces.
First picture one brace is clamped and the CF is laid out on the brace path. Yes it is messy but this time I had about the right amount of epoxy so I did not have any trouble laying down the brace. You can also see the holes
I pull the pins once clamped down to keep them from getting epoxies in place
Just waiting for the epoxy to cure. I used alcohol and naptha to clean off excess epoxy
Sept 26th 2017
I have finished the top bracing and closed the box. So far things look and sound good.
From the last post I epoxied the smaller braces on and then laid CF tow on all of the braces.
While the epoxy was curing I fit the back to the rims, marked out the recesses for the transverse brace and routed them with a small mill grinder.
The upper transverse brace is mostly flat with a slight radius planed on the ends. I mark out where the braces come through using a scalpel. With a razor saw and the brace placed in a vice with just the depth of the channel exposed I clear the channel with a razor saw and chisel. I only inlet the treble (cutaways falcate brace as it was so close to the linings and I did not want to hurt the integrity of the brace by cutting a 5 mm deep channel through it.
I carefully aligned the top in rims, keeping in mind the placement of the top also places where the 12 fret ends up as the bridge is already placed. With everything set up I marked and routed the rebates for the upper transverse brace. The top fir perfectly on the rims and I am bery happy with the slope of the upper bout. I changed the way I radius the top from my previous SS guitars. On this guitar I first flattened the top with the back of a radius disk, I then radiused the rims just past the waist leaving the rest of the upper bout flat. There was enough slop in my sanding to assure that the change from radiused to flat was blended in. In the past I radiused the entire top with the 32' radius dish, this always gave me too much of an angle. So I would then flatten the upper bout putting pressure just above the waist. I would then flatten until the angle was correct. My new method allowed me to nail the angle with a lot less sanding. Thanks to John Hall for describing me method.
My cat did not want me to work.
With the top positioned I cleaned things up, mounted some K&K pure pickups and closed the box. I glued the back on first in the mold clamped onto the radius dish with the spreaders side to side and the neck and tail blocks supported. I glued on the top out of the mold.
Glued on the top
Getting ready for the bindings I worked on cleaning up the sides. I use a small drum sander on my drill. I sand only until most of the pencil marks I use as a flattening guide are gone. (THis tool removes wood fast so care is needed). Also I am sensitive to cocobolo so I took extra care on dust control,