Matthew's Guitar Coming Together

Next I started notching the sides so that the x brace and the upper transverse braces can go all the way through the sides. I set the ribs on the top and marked there width and depth.


I notched the sides so that the top would fit on flush.



Next I marked where the top would be cut to.


Then I sanded it down to about 1/8" over-sized so that the over hang would not crack the top when I clamped it up with bungee cord.


I slid the top out of the mold at an even amount.. Since the back changes in depth I had to support it through the clamping.


So I made some blocks to fill the gap.



Next I put sheet rock screws in the holes that I drilled during that first week.


Next I glued the top to the side kerfing and clamped the neck and tail block areas. Then I wrapped a 40' bungee cord around the body using the sheet rock screws to even the out the pressure.


After it is clamped for 2 hours I took off the bungee and it's really starting to look like a guitar.



I still have some of the top hanging over.


David shows us how to trim it flush with the router.


Nicely done.

Matthew Refining the Top

Before gluing in the top, I took the clamping caul I made for gluing in my bridge plate a few weeks ago and made a new caul. I will use that to glue on the bridge after my guitar is finished. I added some more plywood, cork and plexi so it will fit over the braces.



The last step before gluing on the top is called "voicing the top". The braces on the back of my top are meant for not only strength and stability but play an important role in how the guitar sounds. So voicing involves a process of checking for stiffness as shown by my teacher David Vincent.


Tapping the board and listening for the value of the tone.


Then shaping and resizing the braces to get the best possible sound.

Here is a before and after...

Matthew's Rib Structure

Now lets get to backs & sides... first we thicknessed the backs.




Next I shaped the ribs. First I found the book match that I wanted on the bottom of the guitar.


I double stick taped them together. Jointed one end, traced the outline and band saw/sanded them to the shape of my template.


I marked the outside of the guitar and marked which side would connect to the top and which to the back of the guitar.


Now it was time to bend the sides. We did this with heat and a mold. First we wraped the sides with a wet paper towel, then wrapped it in aluminum foil.


Then I measured and marked the spot where the center of the waist was going to be.


I matched this with the waist line.


I then sandwiched my rib with a heat blanket and 2 pieces of spring steel.


I heated it up for 45 seconds. Then I clamped the waist in.




smoothed down the sides very carefully and clamped them with jorgenson clamps.



I let it cook for 1.5-2 minutes more. Then let it sit for 15 min. Re-adjusted the rib and re-clamped it. Cooked it for another 2 minutes and let it sit for 10 minutes. and then,,,,,,,,,, whah-lah!


Then I put into the mold that I made and clamped it up.


Earlier I used a turnbuckle and some maple blocks to hold the center cauls in place.



Cutting into the maple, drilling holes and filling them with glue and dowels.


I did the same thing to my other rib and then it sits in there like that.


So after I shaped my sides I had some extra side wood left over. So I marked the centerline and sawed off the excess so that the 2 sides fit perfectly in the mold.


Then I made a tail block and a neck block for the guitar. Mine are made out of mahogany and they are cut 1/8" tall to over compensate. The thick block is for the neck. Later I will route a dovetail fitting into it so that I can set the neck.


Before gluing them in I need to make them sit flush against the sides. So I took out the sides and placed some adhesive sand paper on the area where the block will sit. Then I sanded the back side of the block to fit.



When the blocks fit well. I shimmed up the mold 1/16" to spread the 1/8" extra on the top and back of the guitar. Then I used a number of clamps and titebond 2 glue. I use Titebond 2 because it is water proof and if I ever need to reset the neck I can steam it off without ungluing the neck block.



After that is dry I sanded the sides and prepared them for gluing side braces.


Side braces are thin pieces of wood that run from the top to back of the guitar evenly. I used a tape measure to spread them out easily placing 4 on each side.


I used titebond glue. I clamped each brace with 1 spring clamp to clamp to the rib, and 1 cam clamp to clamp to the mold. I also used a thicker piece of wood for a caul.


Afterwards I cleaned up the glue squeeze out and sanded it smooth.


Next I prepped my back for braces. I cut out the back and drew in the brace pattern with a template.


Then I used more strips from my top make a back graft with the grain running perpendicular to the grain of the back.


I used the Go Bar deck with a 20' radius to glue the graft in. First I used a straight edge to line the graft up and removed it once the go bar sticks were in. I also used a go bar stick as a caul.




Next placed the aforementioned template on the back and clamped it down.



Then I used the flat edge of my chisel to cut down into the graft.


Next I used a skinnier chisel to remove the slots for the braces.


I radiused some brace material and used a jig to taper the ends. We used a jig because we have another jig from slotting into the sides later.



Here I've made up some more radiused cauls.


Next I placed the back on the deck with the template clamped over it.


Then I glue the braces in with the template on so the are perfect. I used Titebond.


Then after 15 minutes or so I came back, removed the template, cleaned up the glue squeeze out and reclamped for an hour.


Next I began to glue in the kerfing. The kerfing is used to glue the top and back to the sides.... because I have the side braces in... I have to notch out the kerfing so the braces fit and the kerfing sits flush. I do this by using a thin strip of adhesive sandpaper on a piece of plexiglass. This helps me to notch it the perfect depth.



I clamp up the kerfing with about 100 clothes pins and rubberbands.


I used Titebond glue and leave the kerfing 1/32" - 1/16" over the rib.


And there it is!


Next I put a radius into the edge of the sides and kerfing. I marked the edge with a china marker.


For the top, I put sandpaper on a radius bar, balancing one end on a block and sanding down the other edge til the mark dissapears. I use a 20' radius for all the top except the neck block near the upper transverse brace where I use a 25'.


Then I turn the radius bar and sand the center.


For the back which has the same radius of 20' I use an abrasive radius dish. I place the sides in and turn it back and forth until the marks disappear.


Now its all ready for the top to be fitted and glued in!

Matthew's Acoustic Top

Next we thickness sand the top...

Then we used a jointer plane and a shooting board to trim each piece perfectly straight.


We used a light board to check to make sure there were no gaps.


This jig is used to glue the top together using pressure from the sides. We use hide glue for the majority of the building process.



and the result... 2 becomes 1.


Then I went to my top in which was joined together last night and I am happy to say has a great looking, nearly invisbale glue-joint.


I then thickness the top (again) to a frightening 3.5mm. You can really feel the stiffness along the grain now and you can feel an amazing flexibility across the grain.... spruce is cool.


I cut my top to a rough shape and kept the left over pieces which I will use for different braces and grafts later.


Next we started to install our rosettes. First I clamped my top to my workboard and I drilled a hole in the center of where my sound hole would end up.


So I used a compass and drew out my soundhole, 3 7/8 diameter, and my rosette, 1/4 inch outside of the soundhole. I stuck a short pin through the hole and into the work board.


I then set up a router using a circular jig that sat on the pin. I set it for about half the thickness of the top wood (1.5mm).


And the jig gave me a perfect circle.


I set my rosette in and glued it with titebond.


It glued in pretty nice.


I scraped and sanded the rosette flush with the top. Now its time to cut out the sound hole. I set up the router again. This time setting it deep enough to go through the top wood and into the workboard. I set the jig up and locked it into place for my 3 7/8 sound hole diameter.

So I went ahead and routed it and now you cant even tell.


So I flipped the top over and sanded the inside to 150 grit from the 80 grit scratches from the thickness sander... drew my center line and marked the lines for my braces.




I then started to put together braces. I cut down brace stock to the approximate size using very straight grained Engleman spruce stock. I used quarter sawn pieces so that the braces won't want to twist or distort. We then sent them through the thickness sander so that they would be the perfect width. We had to radius the braces with this jig. I am building a Gibson style so I am using a 20 foot radius.




After I put a radius in the braces I want to glue them in. I have to glue them in different groups and shape them in between gluing... so first I started with my X brace... The most important of the top braces.

First I used a carpenters protractor to get the exact angle of my x brace... which for the Gibson bracing style is 103 degrees.


Then I marked it on my braces... I marked it on the top of one and the bottom of the other so they will fit together..


Then I used my Japanese saw to cut the grooves in them.



It took a while to fit the braces so that they were snug and at the perfect angle... but eventually I got it.

Now its time to glue them in. To get the most amount of downward pressure we use a go-bar deck.


It has a radius dish in the bottom.


And you use these long sticks to create firm downward pressure.



It also helps to glue a lot of things a once.


So I used hot hide glue again and glue each brace in one at a time... then wait for 2 hours.


Unfortunately after I glued I noticed that I had a cracked brace...


I tried gluing it back together with more hide glue and a smaller clamp..


But it broke apart again during shaping.


I decided that this brace is just too important... since it was the bottom brace I had to get rid of both of them, so I planed them all the way off and started over. re-sand, make new braces, thickness, knotch together and glue.



Once the new x braces were in.... I planed them to height, shaped them and scalloped the ends using my block plane, finger planes, chisels, and sand paper. I will do more to this later when I "voice the top".


Next I preped my lower transverse braces and my finger braces. These taper to 1/8" and sit right against the X braces.



Since I scallop these before gluing I have to use clamping cauls so that I have a level surface and I dont dent the soft spruce.



Next I glued in my upper transverse brace.... since this brace is near where the neck meets the body... I cant have too much radius, so I glue this brace in at a 25' radius instead of 20'.


Next I am going to make my bridge plate. The strings of the guitar go through the bridge and through the top of the guitar... They are pulling at the top with around 180 lbs of pressure.... so I use a hardwood to reinforce the bridge... in this case Indian Rosewood.
First I use paper to make an outline for how big and what shape the plate will be so it can fit in between the X braces and lower transverse brace.


Then I trace it on the plate.


Cut it out and fit it.


Then I use some of my leftover topwood to make 3 soundhole braces and the upper transverse graft.


I also use it to make a cap for the x brace with the notched top.


Then I glued them all in using cauls made of wood and plexi.



Then I shaped the cap to reinforce the X braces.

Matthew's Blog - Getting Started

My name is Matthew and I am currently building a Orchestral Model acoustic guitar. First we started making templates for our instruments out of 1/8" plexi-glass. We made blueprints for our guitars and templates for the body shape, neck, headstock, and the sides.


Then we began making outside molds. These will be used to shape the ribs (sides) of the guitar after we bend them. They are made by stacking and gluing plywood.


Cutting them to shape.




Here we're using a template pinned in place to rout them flush so the ribs will be held to their shape until the the point where the top is glued on.


Now we glue the first cut out to another rough cut piece of plywood and repeat the routing process.


Here the outside mold is tall enough to support the rib structure.


Meanwhile I also made a work board for my guitar. It's used for holding the instrument as I build.




Next I made some cauls to fit inside the the outside mold for my guitar so that I can keep the ribs clamped after shaping them.