Starting New Falcate Classical.

[johnparchem]

This is actually a restart of an earlier post I was going to make a Western Red Cedar Falcate, but have decided to make another using Lutz spruce with my Panama Rosewood back and side set. The Panama rosewood with is a real special set with great tonal quality. While tap testing even the cross grain tap made a wonderful sounding tone. Here are the tap test results. I joined it with a thin black fiber strip running up the center.





I bent the sides in a side bander and installed a heel block to make a bolt on blot off neck.




I cut out a bunch of 1.7 mm strips for solid linings. I have made them by just laminating them right to the rims. This time I decided to make the linings off of the guitar. I bent a strip of wood thicknessed like my sides, bent to shape of the rims. I used that strip and a half of a outside mold as the mole to laminate the strips into a solid lining. My though was that I could clean up the bottom of the linings with a round over router bit. Later it occured to me that I could cut inlets for the mass block and the side supports. I was happy about the way it cam together.



















I cut out a bunch of stock for back braces and used the 17.5 degree router bit to make the gable on top of the brace.







I laid out the braces cut the rebate in the center strips and used a couple of sessions to glue them to the back in a gobar deck.









I also did some of the layout and prep for the bolt on bolt off neck

THe only new thing was to rig up a finger chopper offer to make the cut of the scarf joint on the neck. It came out clean and square needing almost no work with a plane.







It glued up with no drama





I used a 4 mm strip to set the angle for the truss rod.







I have a fancy 24" radius bit that I used radius the fretboard.



I cut the frets and laminated on a 4 mm thick strip of mahogany to the underside of the fret board.



But foolish me I tapered the fretboard before I router the truss rod slot into the what will be the widge. So I cut it out with a scalpel and a chisel.



I also made the falcate braces laminating Lutz spruce strips that I bend on a hot pipe using molds I made for previous guitars







All caught up with the new blog.

[kiwigeo]

All looking good John...

[Dave M]

Great stuff John. Your build threads are always very informative.

As it happens I was making the scarf joint on a neck yesterday and the particular blade I have on the bandsaw is a bit rough and along with my poor guidance left a lot of work with the plane. Am using 'cedrela' which is incredibly soft so it wasn't hard to sort out but I'd never thought to use a mitre saw. (Hopefully not really a chopper off of appendages!) So a time saver which we all have need of.

I also note your use of laths to spread the clamping force over the back braces which looks like a good idea.

You haven't given us the stiffness calculations for the top yet... Will you be going for the 9 mm falcate braces again?
The build I have just started is a classical but using Trevor's shape with a cutaway - this is for me. I play (amateurishly) a few pieces which use seriously high frets and want to see how much the cutaway helps.

[routout]

This is a good thing Visual aspect (has too many pics of Instrument construction already )It is easy to follow makes sense to an old fool like me ,thank you .John.

[johnparchem]

Thanks guy!

I did learn with the miter saw that the backstop I have clamped in is really necessary and really clamped well or the board will shoot out.

I am going to go with 10 mm for the main falcate height, I with going under 190 Hz with the 9 mm brace. Although I am starting to learn that the secondary falcate braces also have a lot to do with the tops resonant frequency. On my last classical I had 10 mm and 8 mm falcate braces. Before I glued on the top I took the secondary braces down to 7 mm and the top really opened up how it responded to a tap.


Up until this afternoon I have been deciding on a top. I had settled on a lutz top from Mario (Curly bear) that look good and had a good tap. But this morning digging through my tops I came upon a Carpathian Spruce top that I picked up at a Seattle Luthiers Org auction, from an older classical builder. It had a great long lasting tap tone. I did the tap test for thickness and found it is one of the better tops I have tested. It is stiffer 13.5 vs. 12.7 GPa and less dense 397 vs 422 Kg/m^3



Just did a little today. I glued up the top and I have one side of the rims complete. I am mostly using hot hide glue. When I glued up the top I used both the stretched tape and my joining jig. The tape was probably enough and it was very quick to close to the joint before the glue gelled.





Hard to see now but I am using Advanced Shell Technology (AST) A4 kerfed linings. It is a little pricy but it bends in 4 directions so it is easy to follow the 3 meter radius of the back (really 10').

[johnparchem]

I have the linings and the side support strips in. The Book suggests running the side strips to the end of the rims on the back. Since I was using 4 mm strips instead of 6.5 mm I cut them short and capped them with a bit of the kerfed lining to keep the width of gluing service the same around the rims.




Here is how I cheat to make Classical looking rosettes with figured wood ring. I bought a bunch of russian rosettes with various types of purflings or end grain tile purflings. I choose one whos purflings went with the amboyna burl wood that I want to cut a ring out of. I install the bought rosette and then route out the center tiles. They come out clean because once you get close to the purflings the end grain squares that make the tiles just fly out. Leaving a clean purfling. Here is the process.

I joined the a couple of pieces of amboyna purl




Installed the classical rosette in a normal way. I draw out the lines and inch up on them.







Fits so I glue it on



I start in the center of the tiles and slowly work my way toward the purfling on each side until I have a clean channel.







Based on the real measurements of the channel I draw out the lines on my amboyna burl. Leaving the depth of the router the same depth I used to make the channel. Starting outside of the lines of the ring I work my way toward the line. When close I measure the rin to see how it will fit in the channel.







I then run the burl ring side down through my thickness sander until the ring drops out.







Great fit!

[johnparchem]

Moving on I have the rim and the back ready, I have the top within .2 mm of final thickness. I always leave a bit because I always make some scratch to dent.

Here are some pictures from carving the back braces. I have shown my little 2 mm trimming jig before. Everytime I use it I can not get over how much time I saved over getting close and measuring. When I am finished, all of the brace ends are the same so I can also route all of the pockets in the linings without adjusting the router depth. I still need to spend some quality time on the inside with scrapers and sandpaper.













After I thickness the top I glued on a sound hole doubler, not sure why I did not take a picture. With the sound hole doubler on I was able to route the sound hole. I never route through, leave the plug in long into the build. With the top sanded I covered it with 5 mill mylar.

[johnparchem]

I prepped the top to start the bracing, This time I decided to take a couple of passes epoxying the brace to the top. I started out with the falcate braces, I glued them on in a 32' radius dish in my go bar deck. The layup is the top, 4K 5.7oz carbon fiber tow and them the brace. I do not have a picture, but the next day I planed the braces to the target heights with a block plane and profiled them with a small block plane and a bit of chisel work The braces are 10 mm and 7.5 mm at the most.





I prepared the rest of the braces and epoxyed them to the top





I profiled those braces and put a 4K 5.7oz carbon fiber tow on the top of all the braces. I do this in the radius dish to set the radius into the top.



While waiting for the epoxy to cure I cut the neck tenon out on a table saw.





I put a radius on just the outside edge of the transverse brace leaving the center flat. I marked out where the falcate and sound hole braces cross into the transverse brace and cut out the channels using a razor saw and a chisel









I epoxyed the transverse brace down, being lazy I left out the CF. It is a big brace. Under the top I have a caul that matches the radius and flat spot on the brace.



I profiled the brace.



Getting ready to routed the notches in the top linings.



I have a bunch of glue clean up to do; after that I am ready to close the box.

[Dave M]

John fascinating as ever. It sounds a bit mean but I see that like me you still struggle to work cleanly with the epoxy!

I am starting a classical build myself on which I shall use falcate bracing, with a cutaway. I initially thought I would simply use Trevor's medium size steel string outline but having seen his comments on the size of classicals getting too big I have been revising my ideas. (it would have been nice to use the existing external mould)

So I wonder what width your lower bout is, and what your thought process was in the design of your outline?

Good luck with the build

[johnparchem]

John fascinating as ever. It sounds a bit mean but I see that like me you still struggle to work cleanly with the epoxy!

I am starting a classical build myself on which I shall use falcate bracing, with a cutaway. I initially thought I would simply use Trevor's medium size steel string outline but having seen his comments on the size of classicals getting too big I have been revising my ideas. (it would have been nice to use the existing external mould)

So I wonder what width your lower bout is, and what your thought process was in the design of your outline?

Good luck with the build

Thanks Dave,

I know I am horrible with epoxy, I used my gloved fingers too much. Then with this one I had trouble while keeping the CF under the falcate braces so all and all I feel like a five year old doing finger painting. I found that I could over lay the Gore medium size brazing pattern right on a Hauser 37 or 43 template. It worked out as I had a working and bending mold for it and a bending template for a cutaway as well.

[kiwigeo]

The trick with laying in the CF tow is to not use too epoxy, not too much tow and work the tow with a fine paint brush. After a few builds youll get the knack of it.

[johnparchem]

The trick with laying in the CF tow is to not use too epoxy, not too much tow and work the tow with a fine paint brush. After a few builds youll get the knack of it.

Thanks,

I thought through some changes I can make based on my experiences with this guitar. I will put my go-bar deck on the bench and I will have good light. I have been working on the floor. I also will use a fine brush like you mention, and I will try to keep the epoxy off of my fingers. In any case I will close up the body tomorrow.

[Dave M]

Hi John anything new? With such a fast start I was expecting a box closure by now...?

I said I was also starting a falcate classical but ran into a slight problem with the cutaway side so am starting over with a most beautiful set of rippled maple. This means I have a ready braced back when I can find a suitable set of sides to go with it.

One thing I am doing with this build is to do the shaping of the brace ends before glueing to the back using a drum sander. I am always very uncomfortable chiselling with the plate, top or back, just waiting for a lump to be taken out of it.

[johnparchem]

I did do a small trip but I have also got the box closed with the bindings and purflings on.

Shaping in the ends in a drum sander sounds like a good way to go. I got away from preshaping my braces when I started to use a vacuum box, the change in height in such a short distance did not really work with my vacuum box. Although for this guitar I used a gobar deck. I have my handy dandy jig that I use to both size the brace ends and protect the back.



I need to make a bunch of check lists for some of the major assembly steps. Like before closing the box: Install the end-graph ___. I happily prepared a batch of hot hide glue and glued the back on. Somehow I managed to get the hot hide glue on and the back clamped before the glue gelled.



Whoops no end-graph. I see a lot of builders who cut the rebate after closing. I hate to because I cut into what was to be the finished part of the top once. So before gluing on the top I did cut the rebate and install an ebony and maple strip graph. I used a scalpel to cut mark and then cut out the outline of the graph and I cleared the rebate with a chisel. And yes I am messy with hide glue as well. It does wipe off with some water.







Again using hot hide glue I glued the top on.



Preparing for bindings I glued on a maple purfling strip with to some ebony bindings. I used titebond III as I hear it was better with heat.



I use my inflatable spindle sander to even up the sides. Truth be told I did a bunch of the leveling of the sides with a scraper. I do this before binding to assure that I have a smooth level surface for the bindings machine bearing to ride index on.



To allow me to join the maple purfling strips I taped a maple purling strip to the back over the end graph. This strip will force the router to lift leaving a purfling strip (and a tape thickness) of the end wedge above the binding rebate.



My binding machine note shown in the pictures is a Fleishman Binding Machine http://www.bluescreekguitars.com/shop/i ... cts_id=140. Instead of using bits with bearing for the depth I installed a Luthier Tool Company binding cutter head on my router. http://www.luthiertool.com/self-alignin ... utter.html

Once I cut the binding channel I cleaned up the end graph area with a hand binding channel cutter.



I fit the binding, including cutting away a portion on the purfling on the end wedge end and glued on the binding with hot hide glue.





Same process for the top, except that the top had three purfling stripts (black, rosewood, black). Because of the additional hassle with the purflings strips I used fish glue. Sorry I do not have a lot of pictures, you have seen me with glue. Fish glue is very messy. My process as to coat the purflings with fish glue and force them together off the guitar. Using about 4 or five strips of tape I installed them on the purfling ledge, making sure they were cleanly on the ledge. I then then back and painted the binding channel with fish glue and installed the binding. The fish glue gets so tacky I was able to remove the strips of tape that I use to install the purflings. Also fish glue has such a long open time that there was no issue with installing the binding and pulling the binding and purflings tight with binding and fiber tape.










I did a bit more work today on the neck while the binding are clearing. Fish glue takes a bit to cure. I used a bandsaw and a belt sanding to do the initial shaping of the heel.

[johnparchem]

With the neck heel carved I was able to set the neck angle, route the pocket for the neck extension and install the extension for the bolt on bolt off neck.













I laminated a brazilian rosewood head stock veneer and a black and white fiber sheets. Shaped the fret board wedge extra to match the headstock angle and glued on the head stock veneer.







I rough cut the headstock shape on a band was and then used spoke shave, plane and chisels to finish the shape







I used my fancy Luthier Tool slotting jig for the slots and the holes and was ready to finial carve the neck.







Heavy work with a spokeshave followed by rasps chisels and sand paper I had a neck





I had been thinking my previous classical guitar classical heels were a bit clunky and with the feck extension one almost does not need a heel so I came up with more of a vestigial heel. It really is only 2 mm smaller than normal. I am getting use to it.





I sanded every thing to 220 filling a few gaps and chips in the rosewood along the way and then for the first time used a water based clear filler "Aqua Coat". After z-poxy is was a pleasure to work with. It mostly filled the pores.





With a few wash coats of shellac.



I pored filled the neck with a finishing grade thick CA. I am currently in a spray schedule for post catalyzed Royal-Lac





During my last classical guitar project I made an extra CF reinforced walnut bridge blank. In between spray sessions I got to use my mini milling machine to make a classical bridge.









I will ebonize the bridge with a vinegar and steel wool solution. So I started that as well

[Dave M]

John that is already looking very smart. That back wood is very attractive.

When I tried Aquacote recently I had to use several goes to achieve proper filling. Maybe my technique wasn't so good...?

I seem to remember you didn't use hide glue in the past. Has there been a lightbulb moment?

Cheers Dave

[johnparchem]

Thanks Dave, I was all set up for jot hide glue. I just never was brave enough to use it. Working on the repair of the 51 Martin finally pushed me to give it a try. It went OK. I really appreciate being able to reactivate the glue and not have to clean it out when re-gluing an area. I was able to get the top and back closed with it, I had a couple areas that did not glue, but I applied a little heat and some fresh glue in the gap and applied clamps no issues at all.

My pore fill with Aqua Coat was not perfect. The sanding it takes to remove the filler from the wood, opened some long grain like pores. I could have applied it 100 times I think with the same results. After I leveled the first day of spraying today most of those pores went away.

The post catalyzed finish should be hard enough to buff out on Wednesday. Maybe I can get the guitar strung up next week.

[johnparchem]

Sorry this is such a big post but it does finish the guitar...

I pore filled the body with AquaClear and sealed with 2lb cut of shellac and sprayed post catalysed Royal-Lac for a finish. It took me a day to figure out how to spray the product cleanly. I used a HVLP spray gun with a 1.2 mm tip. I sprayed five coats the first day> I am sure I sanded most of it off. THe second day I sprayed on 5 clean coats. I leveled the next day and finished with three coats. Three day later I wet sanded and buffed. I really like the look and the feel of the product.



With the finish on, I placed the bridge, cleared the bridge location with straight edge razors with a follow up light sanding.









I used an LMI vacuum clamp to glue it on.



I just used a hammer to drive the frets.









Except for the last two bits of fret wire. I widened the slot and used CA to glue in the last fret.



I roughed out a nut.





Here it is all strung up









I used visual analyzer to take a frequency response curve. I was a bit off of my target frequency's. I was hoping that a top resonance of 190 Hz and the back 4 semitones above that. But I ended up with a top resonance of 186 just above F#. My back resonance was 232 Hz which is 4 semitones above 186. Unfortunately everything is close to being right on a note frequency.




As an experiment I decided to stiffen the back using a trick Trevor told me to move the back a little higher with the hope that the top resonance would also move a bit more off of F#. I make my braces as shown in the Book with a gabled profile using a router table and a 22.5 degree router bit. I pre profiled the lower bout back brace carving a bit too much out of the center, resulting in a lower frequency for the back than I wanted.

Trevor suggested splitting a section of brace in half and gluing the outside (non cut side of the brace together to make a good fitting cap. Pictures make this easier to see.











The additional height on the brace raised the back frequency up to around 255 Hz with very little coupling to the top which moved toward 190 Hz. I shaved almost all of the height off of the cap with a small plane, mostly counting on what amounted to sister beams on both sides of the original carved out brace.

In any case after a lot of carving I ended up with a top between 188 and 190 Hz (depending how I hold the guitar while tapping) and 245 Hz for the back. The guitar still sounds good. I never really heard any problem with the original response, but it was fun to play around. Also note the relative back response is a little less than the original FRC.

[lamanoditrento]

What a great thread. I especially like seeing the practical measures taken to change the FRC

Also great looking guitar!

[simso]

Nice,

I like the rosette router base as well, very neat.

Steve

[kiwigeo]

Nice trick splitting the brace to make an add on......I stuffed around getting a piece of bracing to sit on a flat spot Id sanded in the top of the main back brace..it worked but looked horrible.