Madkrafter Posted February 24, 2015 Report Share Posted February 24, 2015 In 2003 I started on my first guitar. In order to make things easier on myself ( ) , I opted to go against the grain and build an acoustic guitar of my own design, from scratch, and build all of the jigs myself. Well, 18 months later, that first guitar emerged and I was hooked. I spent the next 6 years focusing on guitars. In 2009 I was laid off and ended up moving to Utah to be with friends and some work. Getting my shop set up again, I was looking to get back into building guitars after a 6-year break. My Mom was moving out of our family home of 35 years in the Chicago suburbs. I was back in Chicago when she asked to help break down some big, old pieces of furniture to throw out and prepare for the move. Another piece was her 1960 Wurlitzer piano that was deemed untunable, unfixable, un-give-away-able! It was just DONE! I told my Mom that I wanted a crack at it to salvage some potential guitar parts and proceeded to deconstruct it. This journal is my way back into guitar building after 6 years. The entire soundboard and braces are coming from the Wurlitzer. The back and sides are some walnut that I've had stashed since I stopped building. It was the perfect project to get me back into it and a perfect way for my Mom to keep a bit of the piano that she's had since her Sophomore year in high school. ...So, here we go!! (Warning - there will be a lot of photos!) The soundboard and harp are off! The harp is still attached by all of the string pins which are threaded into the hard maple pin block. I had to go to the local Woodcraft to buy a saw to get to my parts. The soundboard had a few cracks in it, which I had to work around. Otherwise, it was good, old-growth quartersawn spruce. The spruce is pretty thick - about .300". I'll be taking it down to about .100" I design all of my guitars in Adobe Illustrator at full-scale so that I can print sections out for templates and patterns. I had my laptop with me and pieced together some letter-sized prints... I found a good section. Cleaned up and sanded to .110" Quote Link to comment Share on other sites More sharing options...
Coop Posted February 24, 2015 Report Share Posted February 24, 2015 Although I'm not a musician, this is going to be an interesting thread to follow. Good luck and keep the pics coming. Quote Link to comment Share on other sites More sharing options...
Tom Cancelleri Posted February 24, 2015 Report Share Posted February 24, 2015 I bet the tap tone of that soundboard is fantastic. Any idea the ring/grain count per inch on that soundboard? Looks like a nice piece of wood. Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted February 24, 2015 Author Report Share Posted February 24, 2015 The spruce was pretty flexible which is why I kept the thickness over .100". The tap tone is a little muddy now but the bracing will tighten it up. This is basically an OM sized guitar with my own spin on the overall shape. The grain count varies across the board, but the middle reads about 25 lpi. The bracewood from the piano will become the guitar's bracewood and some of it reads 32 lpi. Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted February 24, 2015 Author Report Share Posted February 24, 2015 Now to route for the rosette. I'm using this plunge base for a Dremel with some tiny downcut spiral bits. With the channels cut, I glue in the purfling strips with a teflon strip as a placeholder for the shell. Once the CA glue is setup, I remove the teflon and start laying in the Paua Abalone shell. With all of the shell in place, I send the top through my thickness sander and sand the purfling strips and shell flush. The rosette channel depth is a touch deeper than the shell thickness. That way, I sand until I just hit the shell. This brings the top to about .105" thick. The top inlay is done with the addition of the Wurlitzer serial number. The serial number was stamped in the hard maple pin block of the piano. I cut it out and thinned it down. I put it just below the surface and will fill it flush with epoxy. Quote Link to comment Share on other sites More sharing options...
..Kev Posted February 25, 2015 Report Share Posted February 25, 2015 Very cool! Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted February 25, 2015 Author Report Share Posted February 25, 2015 With the soundboard under way, I thought I would work a little on the back. I glued up this bookmatched walnut 6 years ago but never got the chance to use it. So the first step is to glue the back spline. It is a piece of spruce with grain that runs perpendicular to the walnut grain to reinforce the back glue joint. Next are the back braces. I made two radius dishes for the top (28 foot radius) and back (16 foot radius) of the guitar. One half of each dish is plain and the other has sandpaper attached. After sanding the 16 ft radius into the braces, they are glued to the back in what's called a go-bar deck, using the "naked" side of the 16 ft radius dish as a form. Thin fiberglass rods provide clamping pressure. What I didn't show: Before the back braces go on, the spline is notched and scraped back to the walnut to allow the braces to be glued all the way across the back. A little sculpting and sanding and the back braces are done. Quote Link to comment Share on other sites More sharing options...
Tom Cancelleri Posted February 26, 2015 Report Share Posted February 26, 2015 Nice GoBar deck Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted February 28, 2015 Author Report Share Posted February 28, 2015 Bending the sides can be done two ways - freehand, over a hot pipe or in a bending machine such as this Fox-style one, first made by luthier Charles Fox. The original plans called for lightbulbs as the heat source. I did that for my first guitar, but have since upgraded to silicone heating blankets for a more consistant heat source. The wood is misted with water and the wood and heat blanket are sandwiched between two stainless steel slats. A caul is cranked down to the waist area of the guitar. The vertical springs in the photo keep counter-tension. Then the ends are tied off and the sides "cook" for about 15 minutes (250°- 325°) After a cool down, the bent sides are placed in the body mold to set. The center line of the mold is then used to mark the sides for trimming. Next, the tail block is glued in... Followed by the neck block. I use a bolt-on neck. I have made a jig to help keep the neck block vertical while glueing. Quote Link to comment Share on other sites More sharing options...
davewyo Posted February 28, 2015 Report Share Posted February 28, 2015 Thanks for posting this build. Although I don't know the first thing about building musical instruments, I find the whole process to be fascinating and instructive. Luthiers seem to be masters of the shop made jig, and seeing how you get the precision you need is a much needed lesson (for me). Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted February 28, 2015 Author Report Share Posted February 28, 2015 Thanks Dave. I thought the average woodworker would find this build interesting. You are right, jigs are essential to building guitars. I have BOXES of them! Over the years, I've even rebuilt many jigs mostly for better precision and repeatability. 1 Quote Link to comment Share on other sites More sharing options...
Tom Cancelleri Posted February 28, 2015 Report Share Posted February 28, 2015 Jigs, jigs, and more jigs. When I first started building guitars, I made a pendulum jig to hold a router to make radius sanding blocks. Built a bending jig using 3 x 150 watt heat bulbs, ductwork stock for a housing to keep the form protected from the heat. There are a million things to make. 1 Quote Link to comment Share on other sites More sharing options...
Eric. Posted February 28, 2015 Report Share Posted February 28, 2015 This thread is awesome. Keep it coming. Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 1, 2015 Author Report Share Posted March 1, 2015 Thanks Eric. I certainly will. Mom is waiting for her new guitar! Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 3, 2015 Author Report Share Posted March 3, 2015 Now that the neck and tail blocks are in, the next thing is to sand the radiuses (or radii, if you're Latin) into the rim on the top and back. The rim is locked into the mold and the appropriate radius dish with the sandpaper is used to make the spherical cut. Before bringing it to the sandpaper, I thought I would try something different this time. Usually, the first bit of sanding can induce quite a bit of chatter as the sides have been rough cut to the profile on the band saw before bending. Using a 1/2"-3 tpi resaw blade doesn't create the smoothest cut (I was too lazy to change the blade). There are many points of contact and a couple inches of .085" material hanging out of the mold. It can be scary, as you can crack a side (at least it sounds like you could). When you're talking about several hundreds of dollars for a guitar back and side set, you don't want to crack now after you made it through the bending process OK! I learned this trick when trying to get an idea of how to rough cut the profile for this brand-new body shape. To make things interesting, there is a 28' radius in the top, a 16' radius in the back, the guitar body curves through the depths of the radius and the depth of the guitar tapers down 3/4" from tail to neck. When you're looking at a straight piece of wood, your cut line gets a little funky. The solution is to scribe it as it sits in the radius dish... With my scribe line drawn, I plane to the line... With the exception of the neck block angle (I forgot to cut approximate angle for the top), the result is pretty darn close... Now I just sand, sand, sand, until I see fresh wood all around. Just a little more to go... Quote Link to comment Share on other sites More sharing options...
Tom Cancelleri Posted March 3, 2015 Report Share Posted March 3, 2015 Did you make your radius dishes or buy them already made? Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 3, 2015 Author Report Share Posted March 3, 2015 Made them myself (and tons of MDF dust too!!) However... While replacing the sandpaper for the first time in 13 years, the MDF got pretty torn up. I don't think I'll make new ones. It may be time to BUY some new ones. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 11, 2015 Author Report Share Posted March 11, 2015 So sanding the rim is a bit more than just exposing fresh wood. It's the time to take the sides to their final dimensions. I was shooting for a final dimension of 4.5" at the tail and 3.75" at the neck block for a 3/4" taper back to front (Finished guitar, taking into account the top and back thickness). In reality, I ended up with 4.375" to 3.670" (.0705" taper). Close enough for this one On to cleaning up the inside. Starting with glue remnants around the tail block... Then sanding the sides. This also prepares for glue, as freshly planed or sanded surfaces accept glue better. All to get ready for the kerf lining. This lining adds rigidity and glue surface for the top and back plates. I really should get more clamps... The linings are left a little proud... ...because they have to be sanded with the radius dishes as well. That body is getting sexy... The last thing to add to the rim are the side supports. In my stash of Wurlitzer wood, I left the original lacquer on some of the surfaces. This piece will work perfect for side supports... I chamfered the corners but left a strip of original lacquer... The side supports are in. Just a little glue cleanup and the sides are done... Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 24, 2015 Author Report Share Posted March 24, 2015 I got a little distracted with life... back to it With the kerfing in, the last thing to do on the rim is drill for the neck mounting holes. I use a bolt-on neck and countersink the bolts in the neck block. I drill these after the rim is assembled because sanding the front and back radius can alter the position. In the past I've left the countersunk holes exposed. This time I thought I would make a cover for them. I had pieces left over from trimming the sides to length. I've seen this done with just two screws holding the plate. I didn't want to take a chance with the edges curling up and rattling so I went a little "steampunkish" and added a few more screws... With that, the sides are done! 1 Quote Link to comment Share on other sites More sharing options...
..Kev Posted March 24, 2015 Report Share Posted March 24, 2015 Looking awesome! Quote Link to comment Share on other sites More sharing options...
rodger. Posted March 24, 2015 Report Share Posted March 24, 2015 Just found this thread - awesome! Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 25, 2015 Author Report Share Posted March 25, 2015 Thanks guys! I keep plugging away at it between life. Quote Link to comment Share on other sites More sharing options...
Madkrafter Posted March 29, 2015 Author Report Share Posted March 29, 2015 On to the soundboard. With all of the inlay done, attention is turned to the bracing. Most of the braces get the 28' radius sanded into them before being glued on. The first to go in is the X-brace... After the X-brace and tone bars are glued on, I do a little preliminary carving while the soundboard is clamped in the radius dish... Fast forward - tone bars, finger braces, and to the right of the go-bars in the photo - the upper face brace and upper traverse graft... Once all of the braces are glued on, a little more carving and taking the ends of the braces down. A close up of the nice tight-grained (32 lpi) spruce. Most of the braces taper down to nothing before they hit the kerf lining. The exceptions are the X-brace and the upper face brace. They get notched into the kerf lining. Those braces are left long and taken to a height of 0.100" The last piece to get glued on is the bridge reinforcement plate. This plate is where the ball end of the strings go through and is typically a hardwood like Maple or Rosewood. The choice of wood can affect the tone. In this case, I have a piece of Madagascar Rosewood leftover from my second acoustic that works perfectly. Quote Link to comment Share on other sites More sharing options...
Popular Post Madkrafter Posted March 29, 2015 Author Popular Post Report Share Posted March 29, 2015 With all of the elements glued on, there is more carving and tap tuning. Tap tuning is not listening for a specific tone per se, it's listening to how high or low the pitch is and how long the note sustains. I am by no means, an expert. This type of skill takes many more guitars to acquire. I've been pretty lucky so far. You can hold the top in several places. You will find the nodal point which lets the notes ring out. If you hold in the wrong spot, the notes will just die out quickly or make a thud sound. You know when you have the right hold. I think I can call this one good. Everything is sanded to 220 and ready to be joined with the rim. 3 Quote Link to comment Share on other sites More sharing options...
Janello Posted March 30, 2015 Report Share Posted March 30, 2015 This has been killer to follow. Your craftsmanship, as is the story are superb! Quote Link to comment Share on other sites More sharing options...
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