Four Part Harmony

Wow, it seems I’ve been making a decent amount of progress on the guitar project recently. I’d better get a quick update in here, as I’m starting to get behind. I actually took many of these pictures last week, and I’m kind of playing catch up here, so I’ll have to be brief.

I was able to get the heel and tail blocks all glued up last week. This was a big step. I thought I had a problem, as I ended up with some small gaps at each end, but everything will be covered, and everything stayed square and centered. I was worried at first, but hindsight says everything is a-ok.

With the blocks glued in, I was able to start shaping the sides. I used a small hand plane to take everything down close to the final thickness, then sanded everything in the radiused dishes to arrive at the final dimensions. I think I’ve mentioned before, but the top and back of the guitar aren’t flat. The back is formed to a 20-foot radius, and the top is shaped to a 28-foot radius. This work took some time, but planing is fun. I had a big pile of fine rosewood shavings when I was done.

And here’s the guitar sitting in one of the dishes, with the rough contouring all finished up. I sanded both sides in the dishes until the radius was uniform around the entire perimeter of the guitar. Then I started in gluing up the kerfing. the kerfing is a strip of wood that forms to the contour of the top and back, and provides the bulk of the surface that the top and back are glued to. To glue it on, I needed to make a bunch of these high-tech clamps, which consist of clothespins with rubber bands wrapped around them. I had Nicki help make them one night while we were watching a movie.

Here’s the top kerfing all glued and clamped up. I then did the same thing for the back.

Here’s a shot of the sides with all the kerfing installed. I also had to install some thin spruce braces along the sides. It’s almost ready to be joined with the back. First I had to deal with the end wedge.

Here’s a shot of me mid-way through chiseling out a slot for the end wedge. I had a piece of plastic, and some plastic bindings that I had originally ordered for this purpose, but it just looked funny. I couldn’t bring myself to do it, so I got some wood bindings and a small piece of koa veneer, which I cut the end wedge from.

Here’s a blurry picture of the koa and two thin strips of purfling that will be the end wedge. It was a lot harder to get this to fit tightly than I thought it would be. I spent a few hours, over two or three separate trips to the shop to get the fit tight enough to glue in. Then once the glue had dried, I had quite a bit of scraping to do to bring the wedge and binding down flush. This took a few more hours. I thought this was going to be a quick and easy step.

Here’s the finished product. I think it came out pretty nice, and I’m very glad I decided to scrap the plastic bindings.

With the wedge installed, the back and sides were ready to be glued up. I was pretty nervous, and it took me a while to actually get up the nerve to do it. I had to rout some shallow channels for the back braces to sit in, so the back would sit flush with the sides.

After a fair amount of trial and error, and a dry run, I glued everything up and hoped for the best. This was at 12:30 last night. I snapped a few of the wooden dowels that I’m using for clamping bars, so I was worried that I didn’t have enough clamping pressure at the back end. There wasn’t much I could do though, so I pretty much crossed my fingers and went to bed.

Here’s how it came out though. Everything looks pretty good!

Here’s another view.

I’ve also been working on the neck…but that will have to be covered later. So long for now.

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Hello again gentle readers. I’m continuing to make progress on the guitar project. Here’s the big accomplishments for the past week.

Let’s see, I had the rosette all glued up, so I was able to go ahead and cut the soundhole out and start in on the bracing for the top. As I have a tendency to do, I’ve made some slight deviations to the plan set I’ve been working from. I had been reading some things about a bracing design that Martin used on their 1930′s and 1940′s dreadnought guitars. Martin created the concept of an X-brace, and used it to make guitars that were strong enough to withstand wire strings. Their early designs were very lightweight, tonally responsive, etc. etc. They are the stuff of legend.

As those guitars aged, however, some of them began to show signs of buckling and distortion of the top, issues with neck set, etc. Also, with the need for production came a need for sturdier, more reliable construction. So they shifted the positioning of the braces away from the soundhole bit, according to some at the expense of some acoustic and sonic characteristics. This became the standard for guitars in production settings, sacrificing tone for stability (or so it is said). Of course, they also had plenty of high quality red spruce and brazilian rosewood to make guitars with, which are in short supply these days…that might have had something to do with it.

All this is a long-winded way of saying, I decided to use the forward shifted X-bracing setup. I figure, I need all the help I can get in terms of the acoustic properties of the instrument. And if the thing suddenly explodes 5, 10, or 20 years from now, at least I’ll likely know how to fix it.

As with the back, I cut the brace stock from a stick of spruce. Rough cut on the band saw and then planed to width and height. I also sanded the bottoms of the braces in a radiused dish. The top will have a 28-foot radius. It’s very slight, but it does add a noticeable amount of strength. I had to do these braces over the course of several days. Here are the first few, rough cut.

And here they are being glued up. I chose to do these first, so I could carve them without the big X-brace in the way. Also, this way, I was able to tuck the carved ends of these braces into the X-brace.

In this picture, the big X-brace has already been glued in, and now the last few braces and the bridge plate are being glued in. You can see the first braces have roughly carved to shape.

And here is the top, as done as it’s going to get for now! Carving the braces took quite a while. Carving away material from the braces is actually one of the most significant things that affects the tone of the finished instrument. Books have been written on the subject. The general idea though, for someone like me who doesn’t really know what they are doing, is to frequently pick the top up and tap it and listen to the tone. As material is removed, the tone changes, and at some point, you hear a good sound and you’re done. Sounds easy! But it’s pretty subjective, especially when you have nothing to use as a frame of reference. Mine right now sounds kind of “tight”. Not really “ringing” much, but it does have some resonance. I may end up doing some more shaping of the braces, but for now I think I will leave them, and trust that I’ve done all that I need to.

With this step mostly done, I’ll probably focus my attention back on getting the sides ready. I also need to begin the neck carving process.

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Howdy folks. Time for a quick update on the guitar project progress.

It’s been several weeks, but at some point recently I got up the nerve to try to do the side bending. You’ll recall I built this contraption, which was supposed to make the process fairly foolproof. This picture shows the bender with the lights on, heating up.

I took one side, sprayed it lightly with water, wrapped it in some paper, and sandwiched that between the two aluminum slats you can see in the picture. Then I slowly brought the center clamp down tight, followed by the lower bout clamp, and finally the upper bout clamp. It was a little nerve wracking, but everything worked perfectly. No cracking or splitting or explosions or fires.

Here’s a closeup, in which you can kind of see the side clamped between the aluminum slats. This is at full clamping pressure. The fit was pretty good. I left each side in the bender at full heat for about 15 minutes, then shut it down and let it cool overnight.

Then I took the side out and clamped it into the mold to help it keep its shape. I ended up using a lot more clamps than this, as it was important to keep the sides square all around, and very tight to the mold.

The drawback of the bender is that I think I needed to exaggerate the curves to compensate for the woods tendency to want to spring back. I’ve subsequently had the sides back in the bender three times (I re-bent them again last night). They hold their shape pretty well, but still want to splay out at the ends. At this point, I wish I had gone the old-school route, gotten a blowtorch and a length of pipe, and bent the sides that way. More room for error, but much more control.

Here’s both sides bent, cut to length and fit within the mold. In terms of the fit, everything seems just fine. At this point, if they would just hold their shape, I could glue up the end blocks and start working towards joining the back to the sides. I still have plenty of other work to be done though, so I have to keep reminding myself that there is no hurry.

One of the other things I have managed to get done is to glue up the soundhole rosette, which needs to be done prior to bracing the top. I decided to use a herringbone purfling and rosette, which is similar to (but not exactly like) what they used to use on classic old Martin dreadnoughts. Here it is being clamped up and glued into the top.

Another photo of the clamping. When this was all dry, I used a scraper and a big sanding block to get rid of any dried glue and get the rosette down flush with the rest of the top.

And here’s the finished product. That gap at the top is supposed to be like that. It’ll be covered by the fingerboard eventually. This picture also really shows the figure in the top as well.

Next up: gluing up the sides (eventually) and bracing/voicing the top.

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Looking back, the last time I put anything up about the guitar project was back at the end of October! I have been working on it some since then, although the major progress has just come in the past couple of weeks or so.

Since building the side bender, I had to spend a bunch of time getting the sides, back and top down to the appropriate thicknesses. The sides had to get to ~.085 inch, the back to ~0.090 inch, and the top to ~0.100 inch. It’s amazing the amount of difference that actually exists between those measurements, especially with the different species of woods. I ended up doing most of the thicknessing with a random orbital hand sander…not necessarily the best way in terms of keeping everything uniform, but I think it worked OK. I used scrapers quite a bit too, for smoothing things out. I actually thicknessed the sides almost exclusively with the scraper (lots of work!).

I checked my progress along the way with this little thickness caliper that I made.

I’ve been too nervous to actually bend the sides yet, so I distracted myself by moving onto the bracing on the back. I got to use the go-bar deck a few times, and everything seemed to work pretty well.

The first step was to glue a narrow reinforcing strip along the center seam of the back.

Next, I cut the brace blanks from a billet of spruce. The brace billets that I have are nice quartersawn stock. I used the bandsaw to cut them roughly to the proper dimensions, then planed and sanded them to true up the edges. The back of the guitar isn’t flat, but actually has a slight spherical radius to it. I use a radius sanding dish to get the braces to match that contour, and then clamp everything up in the dish.

I glued up the braces 2 at a time. This photo shows the back two braces already glued on, and the front two being clamped up. When I did the back two, the glue squeezed out everywhere, and I ended up with a big mess to deal with the next day. I did better with the front two.

Once the braces were all glued in and cleaned up, I set to work with a chisel and plane to carve them down to their final dimensions. This was the fun part. It took some getting used to, as I’m still very new to the idea of woodcarving. But by the end I felt I had a feel for it, and I think the final shaping turned out pretty well. I may have to take them down a bit before I finish everything up, as I tried to err on the side of caution, so I think I left them a bit thick. In general, the lighter you can keep things like bracing, the better the acoustic properties of the instrument will be. The challenge is in balancing that lightness with stability. I read somewhere that the theoretical ideal instrument should be just on the verge of imploding upon itself.

Another shot of the back bracing. After getting everything finished up, I cut the outline of the guitar out (leaving about 0.5 inch all around at this point).

And here’s the “finished” back, all cut out and actually looking kind of like a guitar! When I get a chance, I’ll start on the bracing for the top, which will be significantly more complicated.

Oh, and here’s a picture of Anna hanging out with me in the workshop. She asks to come down at least once a day. She likes to sit on the workbench, play with the measuring tape, and collect wood shavings mostly. Papa’s little helper!

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Not too much news on the guitar front, but here’s an update anyway.
I actually finished making this side bending form a week or so ago.
It made for an interesting project.
Embarrassingly enough, I had to relearn everything I had forgotten about electrical wiring.
I got it all wired up properly though, even put a timer switch on it as an added safety precaution.

3 150W bulbs in this box lined with foil tape.

And here’s the completed bender.
There are clamping cauls at the waist of the guitar and at either end.
The general idea will be to use the lamps to get the temperature inside the box to around 250-300 degrees. The individual sides will then be moistened (with rosewood some people even soak them apparently) and then placed between the two aluminum slats that are laying across the bender in the photo, and slowly bent around the form, clamped and left to cool.

I’m pretty eager to give it a try, but I need to take the sides down from their present thickness (0.100 inch) to the final thickness (0.085 inch). I intend to sharpen some scrapers and try my hand at scraping them down, but may also end up sanding them.

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Hey folks, I wanted to put a few photos up while I have a second.
I’d say I haven’t been spending a bunch of time working on the guitar, but that wouldn’t be entirely true.
I spend at least an hour or so down in the basement every night after we’ve got Anna to bed and have had some time to wind down a bit.
Often times I don’t really get much done besides a bit of reading or putting together a small piece of some jig or something, but I guess it’s all useful time spent.
I have made some progress though, and with any luck I may bay be ready to bend the sides in the next week or so (we’ll see).
Here’s what’s been done so far.
Here’s the guitar body mold all finished up. IT took some doing to come up with a system for opening and closing it, but I think my method will work pretty good. Also in this picture are three spreading clamps that I built that will hold the sides tightly in the mold once they are bent. As with everything so far, I worry that they aren’t built to the level of accuracy they should be. The sides of the mold are very smooth, but not perfectly smooth. I should probably be cutting with a bandsaw and sanding with some sort of spindle to keep things in square, but I’m making do with a skil saw and an orbital hand sander. Not ideal, though I think everything is working out pretty good so far.

Here’s the latest project, the top half of the side bending form. I’ll build a box underneath it with two 150 W light bulbs to serve as a heater. The wet sides will be clamped to the form while being heated. There are also silicone heating blankets that some people use, which are supposed to be a bit better/easier, but they are also pretty spendy. This will be a pretty cheap form when all is said and done.

And lastly, here’s a shot of the go-bar deck. This is also serving as a work table, but eventually it will be used to clamp up braces, and attach the top and back to the sides.

I still need to work out how best to go about putting together some radius dishes for clamping purposes. It sounds like a laborious, dusty endeavor, especially with my laminate router, and I am considering just purchasing some, but we shall see.
More updates will be forthcoming, as soon as I actually have something interesting to take a picture of.

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I cheated a bit.
That first post was actually made almost a month after those pictures were taken and the wood was sitting in our guest room.
Well, it’s a month later and that wood is still sitting in the exact same spot.
But there are good reasons for all of that.

See it turns out that you don’t really just start building a guitar.
No, you start with a small pile of 3/4″ birch plywood and you start making jigs.
Woodworkers love jigs, and they dream up some really beautifully ingenious ones.
I have begun working on three important pieces of equipment that I’ll need to have before I can really get down to the real work of making a guitar; 1) a guitar body mold 2) a side bending machine/template; and 3) a “go-bar” deck for gluing up braces.
They of course sell all of these things commercially, but they are expensive and it has actually been a large part of the learning process to figure out how to go about making these things.

A few photos before I get too tired to type any more.

First, a shot of the “workshop”. Everyone posts a pictures of their awesome, well stocked, super efficient workspace and all of their tools, so I figured I had to do the same. This is my little corner of the basement. Things may improve some if I get a chance to do any organizing, but for now this has actually been working out pretty well so far. I keep the guitar wood upstairs still, where the humidity and temperature are more favorable.

Here’s one new tool that I did acquire, which is already proving itself in spades. A little laminate trimmer, which is serving its purpose as a poor man’s router. It’s worked wonders for truing up the sides of the mold.

Most shops would have a bandsaw, and I may still need to find one. But for now, my trusty $49 skil saw is doing my rough cuts on the plywood. It works just fine, if maybe a little slow.

My main consideration, in all honesty, is noise. I’ve so far been really only getting any time ot work on the guitar in the evenings after our 2-year old daughter Anna goes to bed. I run the skil saw, the trimmer, and an orbital sander, and listen for any sounds of her waking up. No problems so far.

And, last but not least, here’s my progress for the week! Doesn’t look like much I know but trust me…I got an accurate template cut out into some hardboard (not as easy at it sounds), then transferred that template to the plywood, cut out six of these half shapes, routed them all flush, and finally was able to glue them up tonight. These will be the two halves of the body mold.

Like I said. This is probably going to take a while.

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As anyone who knows me knows, I happen to be interested in musical instruments.
Especially, stringed musical instruments, and especially guitars.
As long as I can remember, I’ve been fascinated with lutherie, but it always seemed the territory of a) expert woodworkers/craftsmen with decades of experience; b) people with a lot more money and time on their hands than me; and c) people with a fantastic array of specialty tools and a 2000 square foot, climate controlled shop in the backyard.

This bothered me. For a long time. Then one day a month or so ago, I just decided that even if it took me ten years from start to finish to build just one guitar, I was going to go ahead and get started.

I ordered some wood.

Now before I get started, I’d better get a few things out of the way. there are a lot of people out there building guitars. And there are a lot of people doing just what I’m doing, with little in the way of experience but with more than enough curiosity and determination to make up for it. And a lot of them keep a record of their building process on a blog or website (how do you think I got the idea that I might be able to pull this off)?

So it seems there are a few required photos that everyone has to take to get started so here goes…

Here’s a shot of everything that came in the big box o’ stuff that I ordered from LMI. Some small tools like clamps, a chisel, a plane, but most importantly, the wood that will become the guitar. A chunk of Mahogany for the neck, East Indian rosewood for the sides

Here’s a shot of the blueprint. It was (and continues to be) a bit of a mystery how I will be able to get accurate measurements from this thing, but so far so good.

Here’s the East Indian Rosewood back plate. I decided (after a lot of back and forth) to have the plates joined and roughly thicknessed by the shop, rather than try to do it myself. In retrospect, I kind of wish I hadn’t because those would be good skills to learn, but with my minimal tool selection I though it might prove problematic.

A close-up of the Sitka spruce top, also joined and thicknessed. This thing is very, very light, and it seems to have some interesting figure to it.

Stay tuned, and feel free to leave comments if you have any questions (or better yet advice). I have a feeling this might take a while.

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