Cocobolo\WRC Falcate 00 12 fret to the body

[johnparchem]

Sorry my first post will contain a bunch of pictures as I started this guitar earlier in the summer.

I picked up the ziricote awhile ago from another luthier. A great looking set I liked how the sircote 12 string I built sounded and looked so I decided to use this set for a stock build.



Zircote is a dense wood. Luckily it is also very stiff so I can sand this set down enough to build an active back.



I have had the Western Red Cedar for awhile. I liked how one of my smaller earlier WRC guitars sounded so I decided to hear how it worked with falcate bracing. At 3 mm it ends up about 20% thicker than my spruce tops but it is not as dense as most of the spruce I use so its stiffness to density ratio is OK.





I jointed both sets of plates using my rope jig. I use a low angle plane and a shooting board to joint the sets of plates





WIth the top and back joined I played around with a new layout for a 00. I moved the sound hole almost an inch closer to the neck (more like it would be found on a classical). With this change and using a 25.4 long scale, the fretboard will fall nearly in the center of the lower bout. You might be able to see the falcate bracing pattern and the new sound hole location penciled in on my old 12 fret SS 00 template.



With the sound hole location in place I constructed a rosette on the top. The rosette will be 5 thin purfling strips BWRosewoodWB on the inside and outside of a wooden ring. To get the purflings in tight and round I route the channels sized for the purfling stack and install the purflings first. I glued in both in one go and then leveled them to the top.

Size the depth of the routers cut. Just used something the right thickness.


Installation of one of the rings


gluing them in with Titebond hide glue. I use a transparent caul to be able to see if all of the purflings are in place.


With the purflings installed I just sneak up on them with the router





I use the size of the cut channel to make a proper sized wood ring. When routing I start outside of the ring and inside then up of the proper size. The Bishop Cockran router base allows for really fine adjustments to just do it one the fly.





I set the depth of the cut to the desired thickness of the ring. I then sand the back of the routed blank in my thickness sander to the ring drops out.







THe ring dropped right in and I glued in with the titebond hide glue.



I have more but I will create a second post so the first one does not get too big.

[johnparchem]

THis guitar will be built with an active back with a 10' radius. The large bend will stiffen the back allowing a thinner back to have the desired stiffness. To get a good response out of the back it needs to have a relatively low mass. It also needs to be stiff enough to get a good ring tone out of the wood at the desired resonance frequency.

The side templates I have are for a guitar with a 15' radius back. To get the correct profile placed some poster board in my mold sitting in the radius dish and using a compass transferred the profile to make two templates.





With highly figured wood I wash the side with naptha and flip the boards looking for cracks. THis set did not have any. If I did find cracks I would flood them with thin CA.



I profiled both sides on my band saw and thicknessed them to .080". Zircote is a bit brittle and the curves required for a Venetian cutaway are tight. So I pulled out a scraper and thinned the cutaway side from just beyond the waist to the heel end of the side to a bit more than .070".



I also sprayed the sides with SuperSoft 2, wraped them in parchment paper and let them sit overnight.



To give myself the best possible chance of bending the wood in a fox side bending machine, I warmed the cutaway are on the underside with a heat gun. No panic here I just did this while the blanket was heating up to temperature on the other side.





Successful bend!



I almost bent the non cutaway side for the wrong side. I always check a million times and luckily on that millionth time it dawned on me that it was the wrong way. THat side bent with no issues.



To make a heel I dug through my stash of mahogany to find a piece long enough and thick enough with the endgrain off to the sides. With it being a cutaway I need the block to be a finish sand distance more than 29 mm minus the thickness of the cutaway side. My fret board will be 58 mm at the join and I want the fretboard flush with side. The block needs to slope out a bit a touch more than the taper of the fret board so that the fretboard will stay on the top as it extends down to the sound hole.



A bunch of clamps to glue it in.



While waiting I stuck some sandpaper on the rims near the heel and profiled a plywood end block.



With the blocks glued on I draw some reference lines parallel to the still flat top (and perpendicular to the heel block). I have a set of blocks that I use as two sided parallel. I lay out the blocks flat on the table, the mold sits on the top and the rims are pushed flush with base. The mold is used as a guide for drawing the lines. I flip the blocks on end and repeat. Now I have two sets of lines I can use to get my guitar into the mold in the correct position any time I want to pull the rims from the mold. Also when radiusing the rims I have a set of reference lines I can use to assure that I am evenly sanding. I made one line that was two close the end.







I start by radiusing the top of a radius dish. This guitar will have a 32' radius. I am trying something new for me based on some direction's John Hall gave. Instead of radiusing the entire top rims I radiused them to just past the center of the waist. To achieve this I just placed a piece of paper under the heel block while I sanded.



I did a quick check of angle of the upper bout relative to lower bout. I will wait until I have the braced to to fine tune the angle. but it is close.



The back is both radiused and profiled to the correct dimensions. note the blue tape on the top blocks. I can not count the number of times I have started sanding profiled top rims on the backs radius board. Also I have the block sizes marked on the rims. In this case I reached the end block height first. So I put a slip of paper under the block and continued sanding the heel block to size.



Finishing the rims were all standard stuff. I am using AST A4 kerfing for the back (good for the 10' radius). I am using reverse kerfed lines for the top. To get get the kerfed linings to bend with out breaking. I spritz them with water and used the outside of the rims as a bending mold. I also heated the cutaway section to get it to bend.



From there I inlet a bunch of thin side strips into the linings and cleaned everything up.

[johnparchem]

THis is a cocobolo set not Zircote.

[Kamusur]

Looks like it is all coming along very nicely John.

Steve

[johnparchem]

Thanks Steve,

I have two post today in this one the rims are complete, the back is braced and I am starting on the top.

To complete the rims I installed an end wedge using a scalpel, razor saw and chisel. I also have a black purfling line. My binding will have a white and black purfling line. My thought is if things go well I can miter in the black purfling line and let the white go across. If things do not go well both the white and black purfling on the binding will go across the end wedge. I never like my miters, with a single black line I can just butt join and nobody will see the difference.










The back is the active back bracing pattern that I got from the Trevor Gore steel string guitar plans















I laminated a bunch of 1.7 mm spruce strips to make the facate braces. I bend the strips close to shape on a bending pipe.





For those making a steel string falcate guitar this next step is ultra critical. Most steel string guitar builders work to get bridge plate positioned to be very close, but ultimately place the bridge when the guitar is complete based on the position of the nut. Because the falcate braces pass very close between the bridge pins the bridge is positioned at this time. As the build progresses everything is placed from the already placed bridge. Because of this I take care to carefully layout the top and the bridge location.







Installed a sound hole doubler patch.



While waiting for the glue I made a 1.5 mm panama rosewood bridge patch.









I used an LMI rosette tool and a router to cutout the sound hole. I was going to do it all with the hand tool but with the sound hole patch the the tools blade was not deep enough.



I am using epoxy to glue down a carbon fiber reinforced bridge plate





Note the wet area is not epoxy, I just cleaned up very minimal epoxy with some alcohol


Not shown I have a bunch of clamps.

[johnparchem]

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 http://www.luthiersfriend.com/aOtter/Otter.html 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

[Dave M]

As usual John we appreciate the trouble you take to document the build.

I wonder what height you have taken the falcate braces to? Trevor I think suggests7 mm for his particular design for a SS...?

Also I may have missed it but what thickness have you taken the back to given that you want it to be active?

[johnparchem]

As usual John we appreciate the trouble you take to document the build.

I wonder what height you have taken the falcate braces to? Trevor I think suggests7 mm for his particular design for a SS...?

Also I may have missed it but what thickness have you taken the back to given that you want it to be active?

Thanks,

I will have the braces at 9 mm. I always come out lower in frequency than Trevor I hope that this guitar is 180 Hz so I may get 170 Hz. It is narrower than his medium body but about the same length. The back will be 2.4 mm thick. I used Trevor's equation for thickness with his suggested numbers for steel string. Cocobolo is a bit dence to give a strong response but this set is very stiff allowing me ot go to 2.4 mm. So it may be OK.

[johnparchem]

I have finished the top bracing and closed the box. So far things look and sound good. I think I may hit 180 Hz on this guitar. I will have a better idea after I bind the guitar but right now the top resonance is 193 Hz.

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.



Trimed flush


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,









Time for a break

[johnparchem]

Thanks Dan, I have two bengals, they are nutty cats but a lot of fun.

I got the guitar bound with african blackwood bindings and on the top I added wbw purfling. The purfling uses maple for the white so it is not a stark white that one gets from the white fiber used in some purflings.

Twice I tried to bend the binding for the cutaway side in my fox side bender. The first time I spritz with water and heated the cutaway part on both sides, but even going slowly with the press I heard the bindings crack. I grabbed another pair and spritzed with supersoft 2 (let it sit overnight) and bent it the next morning. But I cracked one putting it into my mold for safe keeping. I probably over cooked them as they were very brittle.






I finally went to the bending iron and quickly bent two bindings. On the bending iron they came out cleaner and hold their shape.



Not pictured I use a Fleishman Binding Machine modified to use Luthier Tool Company's Self aligning binding cutter. The binding cutter has its own side index so I am able to cut with a 1/4 end mill.

To cut the binding channel at the neck join I used a hand Karl Holtey Design Purfling Cutter I got from Lee Valley some year ago. It is a very useful but crazily over built tool. I really do not hold it like shown but I was taking the picture.



When routing the back's binding channel, the mill caught and separated a slim area where the figure intersected with the binding channel/ Luckily it did not tear off. I just CA glued it down. When doing the top I thought about suggestions to shellac the sides to help prevent tear out. I went one better I rubbed in a wash of CA glue. With the paper towel I can polish it on the side. Use paper towel, a cotton rag will set the CA off.





The only other tool I used for the first time was a fancy miter cutter. I used this tool to miter the joint at the neck intersection on the cutaway side. It really works and creates a clean accurate cut.





I used titebond hide glue to glue on the bindings and purflings without any excitement.



I did a little bit of clean up and moved on to the neck.

[johnparchem]

whoops binding is Australian Blackwood not African.

[johnparchem]

Moving on to the neck ...
When I build my last guitar I had a neck roughed in with with the tenon and brass inserts installed. I did not use it as I wanted a higher heel for a tradition classical heel. It was cut just right for my cutaway heels. So I got a head start.

I have found it a pain to taper the neck. Ultimately I get it, but I have been considering a jig that I found In the Gore\Gilet book used with a safety planer. The jig is just a board with an index tapered with the slope of the desired taper.





Taking a mm at a time off I am able to get the bulk of the neck at just the correct thickness with the correct taper. It actually worked out well. I left enough wood on both ends to have enough for a transition.



The head stock is just a touch wider than the neck blank so I glued two wings on. I also adjusted the neck angle using an edge plane.



I needed to lessen the angle. To avoid blowing out the face of the neck, I clamped a board over the face of the neck at the height I wanted to plane.



I use a luthiers tool edge vice to hold a router template in place to route the mortise. The picture has a centering template inserted to align the vice.



I have a router bit to radius my fret boards. I do it in two pass flipping the fret board over for the second pass. I cut the fret slots by hand using LMI's fretting slot cutting tool. I rough cut the fretboard taper on a band saw and plane it to the correct taper.







I though on a bridge from the drawer to make sure I ended up with the correct nut location. Looks good!



With a good neck angle as well



I found a cool look BRW headstock veneer and glued it to the head stock. Before gluing it on I angle the nut end (using a properly angled wedge and my belt saw) and use a spacer to set the nut width on the neck. I do not have a picture with the bunches of clamps to glue it on.





I gathered some drawing tools and a cup of coffee and drew out a head stock with tuner holes that supported straight string runs. On my first on I forgot that the post needs to be moved to the outside a half of post diameter as the the string winds on the post. From the post holes I measure a distance so the tuner knobs are in a good place. I use a compass and a french curve to make all of the other curves and arcs.







A little double stick tape, the band saw and a drum sander ...





I use a spokeshave to taper the neck to the fret board.





Usually I just play around until I can create an arc for my heel cap. This time I calculated the radius from the chord length and the saggita and used a compass to make the arc.







I drew some guide lines and then used spokeshaves and rasps to remove everything that was not part of my neck.

[johnparchem]

RIght before I left on a one month road trip I decided I needed to make a new neck. Using a chisel I tore out part of the heel on the side of the neck that runs along the cutaway join. The neck I made will be easy to convert to a more classical heel on a future guitar.
Making the neck mostly was done like I made the first neck here are a few pictures anyway to show some of my procedures. The only major difference I usually transfer the bolt hole positions from the neck to the heel block. In this case I went from the heel block to the neck







Made a new logo.









I glued on the fret board. My truss rod slot was a tad deep so I filled it with a maple strip.



Everything is ready for finish prep. I played around with the headstock transition on the back of the neck using a deeper smaller radius then the first neck.

[ernie]

nice work john , that grain is just wild man!!

[johnparchem]

Thanks ernie!

I finished the pore fill with zpoxy and the grain really pops. I will seal the zpoxy was a few wash coats of shellac and ultimately spray post catalyzed Royal Lac.

[demonx]

Looking good!

[johnparchem]

Thanks! I made some progress. Since the last post I sprayed the guitar with post catalyzed Royal Lac a hardened shellac product.

While the finish was curing I laid up a Brazilian Rosewood bridge blank with two sheets of 5.7 OK 3k plain weave carbon fiber sheet. While I was at it a laid up a blank for my next classical as well. I used a template to drill the holes and to cut out the bridge shape on a bandsaw. I cleaned up the shape on a small drum sander in my drill press.













I used my luthier's friend http://www.luthiersfriend.com/ to make the wings of the bridge. I love this jig. I use it for bridges and to thickness saddles and nuts.



I did not slot it, The location is already set by the pin holes in the top. I first wanted to get the neck angle right so ultimately I will slot it on the guitar.



After the top finish cured I set the bridge and traced around it with a scalpel.





I used razor blades and chisels to clear the finish. I do the bulk using a straight edge razor blade as scraper. I clean the edges with a sharp chisel. With the chisel I work from the inside to the score line. If I am carefull the finish just clears right to the line scored in the finish.

At this point I also made sure the neck was centered and double checked that the bridge will be properly square to the neck. THe bridge was square but if it was not and not too fare off I would have made the neck square to the bridge.





I used a vacuum clamp to glue the bridge on once I was happy.





Starting to look like a guitar.





I use the stewmac jig to route the slot. I really like this tool. Once set routing on the guitar is a breeze.



For the fret markers I went back and forth on the fret markers deciding between pearl diamonds, MOB swallows and gold MOB swallows. My client liked the swallows, I thought the white worked the best. I laid out the gold but was never happy with the way they looked.





To route the pockets for the inlays, I glued them down with a dab of instrument makers glue and trace the out line with a .5 mm mechanical pencil.



I tape down a thin purfling strip on the sides of the fret board so the bottom of the routed pocket was flat. The swallows were lone enough that I could have cracked a feather trying to fit them to the radius.



messy with CA glue but they cleaned up







I thought I was golden until I tried to install the tuning machines and found out I thicknessed the steel string headstock for a classical guitar. About 4 mm too thick!

I pulled out the safety planer and thicknessed it properly to 15 mm and reworked the transition into the neck . Now it looks good but I need to refinish the back of the head stock.

[johnparchem]

I finished this guitar.

Falcate braced western red cedar top
Cocobolo back and sides
Australian blackwood bindings
Brazilian Rosewood bridge and headstock veneer
Post Catalyzed Royal Lac finish









You can hear it, sorry about my playing


youtu.be/

[lamanoditrento]

Very slick The royal lac seem to come up a treat too

[johnparchem]

Whoops forgot to post the final spectrum graph. Everything is not exactly where I had hoped but the guitar sounds great, my target T(1,1)2 was 180 Hz and I am at 181-182 Hz with no mass. Also nothing is right on a note (but the air is close). The back is not super responsive but it does couple. I got a much better response from Koa on one of my previous guitars.

I had about 15 minutes of everything I know is wrong when after a bit of sanding the back brace just a bit, I picked up and tested the wrong guitar and wondered why I was getting 94, 170, 214 Hz. It took me more times testing then I want to admit before I noticed I had my guitar built to Gore medium steel string plans.