Crazy 12-string build

#1
Having had three guitars on the go recently, I vowed to finish them all and then have a little break before starting on a new build. This was a sensible plan.

Of course, that didn't happen.

I started thinking about a future build and got excited. I don't remember which one came first, but this is a confluence of two ideas. The first idea is to make a 12-string guitar, which is obviously a highly sensible move since I've never even played a 12-string - I just know that they exist!

The second idea is linked to the dodecastringiness* of the build, since 12-strings are often acoustic or hollow. Indeed, the tipping point for this idea was when I saw a rather splendid and highly desirable 12-string PRS Hollowbody up for sale at Thomann for a price that would make a significant dent in my pension savings.

Now, I don't know how they make hollowbodies. I've made semi-hollow guitars, which are basically just solid guitars with some wood hacked out of the middle. I don't think that's how they make proper hollow-bodied guitars, though. Hence I'm having to guess / make it up as I go. What I've decided to do is essentially to make the guitar from three main components:
(1) A sort of through neck that will stretch from headstock to bridge, but NOT to the end of the guitar. This will essentially be the core of the instrument, and the throughiness will hopefully make it strong enough for the tension of 12 strings and simplify the build a bit (no neck joint).
(2) Two caps that will be used as the front and back of the body
(3) A stupidly complicated construction for the sides that will feature a kind of chequered pattern made of two woods, possibly with a thin strip of something else between them.

It's going to be an electric guitar but I hope that the construction will make it a little louder acoustically**.

I have spent quite a few hours recently browsing the web for information about, and then parts for a 12-string guitar. I've ordered a Gotoh 12-string bridge, and discovered that it is the same width as a normal 6-string bridge, which means that I can also use standard pickups (hurray!).

Regarding pickups, I tried to bear in mind that the greater number of strings will produce a stronger wibbly-wobbliness in the magnetic thingummy, and so I looked for some (cheap) low-output pickups. I settled on a pair of Tonerider Alnico IV Classic Humbuckers, which I hope will do the trick.

I have found some 12-string nuts on Amazon - although I can make my own nuts generally (I've just done one for the baritone), a 12-string is a different matter and I prefer to buy one. This will also determine the width of the neck - essentially, a 12-string is the same width at the bridge but wider at the nut, so the fretboard simply tapers off a bit less. I'll probably get a 48mm nut.

The last major component is the machine heads (tuners). The headstock will need to be carefully designed to house 12 tuners, and I decided to look for mini tuners in order to reduce the required size of the headstock a bit - it's going to be a monstrosity, but the less monstrousness the better. Strangely, it took me a lot of digging around to find somewhere that I could buy mini tuners without paying a fortune, and I have ordered them from a Dutch website that doesn't have them in stock but claims to be able to get them. We'll see. I went for two sets of Gotoh SG381 mini tuners. Now, in the spirit of experimentation and bad taste, I decided to buy one set in chrome and one in gold, and I will alternate them on the headstock. This is intended to reflect the choice of a chrome bridge and gold pickup covers, but it might just look awful.

So apart from opening my wallet and waving it around until all the money had fallen out, yesterday I actually made a start on some of the parts of the build. Photos of the first bits will appear in the next post.

I'm also going to try to make a few videos about this build to add some more content to my YouTube channel, which has been rather barren recently.

Comments and abuse for my lack of taste and sense are welcome! :)


* I haven't yet checked in the dictionary, but I *think* I may have made that word up. I'm sure it's meaning will be clear, though.
** It probably won't, because I don't know what the hell I'm doing.
 
#2
The two tops that I have picked for the back and front are both zebrano (zebrawood), but radically different grain patterns. Here they are being glued, and then together. I'm probably going to use the one with the curvy grain for the back, and the other (which is burled grain) for the front.
Back gluing.jpg Front gluing.jpg Front and back.jpg

Next, I have cut out some small blocks of sycamore and padauk from leftovers of previous builds, These will be further cut into pieces about 15x40mm, or something like that.
Side pieces 1.jpg

That's as far as I've got so far, and I still have to work on the other guitars so progress will be slow for a little while. More photos will appear when the stars align in a particular, as-yet-undetermined way!
 

Magnus Pym

Grudges rot the soul
#4
Am I right in thinking you plan to contruct the sides by sticking the smaller peices together to form the rough outline of a guitar and then shape/sand them into a smooth shape to match the top/bottom?

I guess that would work. Can't wait to see how this comes out.
 
#5
Am I right in thinking you plan to contruct the sides by sticking the smaller peices together to form the rough outline of a guitar and then shape/sand them into a smooth shape to match the top/bottom?
More or less exactly that. What I plan to do is first to rough cut the top and bottom to the desired shape so that I can follow the outline when I'm gluing the small pieces together. I haven't yet decided exactly how I'm going to do the gluing, i.e. whether I glue the small pieces together first and then glue that construction to the top, or if I will glue them onto the back directly, like building a wall. I need to have a think about which is the most logical way of going about it. I'm tempted to think that it will be easier to do the latter; it means that I will need to do a bit more preparation of the "bricks" before gluing them on, but it should be more stable.

It's probably a disaster waiting to happen, and I expect it will be extremely frustrating and annoying at times, but it should make entertaining reading!
 

Magnus Pym

Grudges rot the soul
#6
Say you have about 4cm for the depth of the sides I guess you could make strips or blocks 2cm thick and lay them like bricks so the overlap gives some area for the glue to bond. This would give the construction enough strength to allow some machining plus would look cool on the finished product.
 

Robstafarian

The Good and Wise Call Me “Rufus”
#8
Regarding pickups, I tried to bear in mind that the greater number of strings will produce a stronger wibbly-wobbliness in the magnetic thingummy, and so I looked for some (cheap) low-output pickups. I settled on a pair of Tonerider Alnico IV Classic Humbuckers, which I hope will do the trick.
I say, you have been paying attention during our conversations!
 
#10
No more progress on the actual build yet, but I have received most of the hardware for the build.
Hardware.jpg

* Tonerider Alnico IV Classic Pickups
* Gotoh GTC12 bridge
* D'Addario 12-string set
* Gotoh SG381 mini machine heads - two sets, chrome and gold

I've also just ordered a Tusq nut from Thomann, together with a few sets of strings to supplement my stock. Unfortunately, I only just realised that I should have also ordered some pickup surrounds, but I can probably find those on Amazon - I have a few things in my shopping basket pending a small order.

I've been mulling over the choice of woods for the neck, which as I mentioned will go through the body and under the bridge. One option is a solid lump of oak that's 7cm square and about 85cm long - just about the right dimensions for this purpose. I reckon that oak should be strong enough for 12 strings, but I'll probably end up doing a laminate neck in the end. My main concern with the piece of oak is that the grain isn't straight through the whole piece, and I'd be aftaid of it warping and ruining the entire guitar.
 
#11
I've been working on making my bricks for the sides of the body....first I stuck them to a board and ran them through my thicknesser to get them down to a consistent height of about 15mm, then I cut those longer pieces into blocks that are about 31-32mm long, aiming at 30mm with a bit of margin for shaping the bricks to follow the curve of the body.
Bricks.jpg

It's going to be a bit painstaking to shape and glue these all together, but they should make a striking instrument. I think the next job will be to work out the neck.
 

Magnus Pym

Grudges rot the soul
#12
I've been working on making my bricks for the sides of the body....
Are you planning to angle the sides of each one to fit the body curves? That sounds like a lot of work. Couldn't you just keep the sides parallel and step them round the body to then use a router or something to shave off the jagged outline from the outside?
 
#14
Are you planning to angle the sides of each one to fit the body curves? That sounds like a lot of work. Couldn't you just keep the sides parallel and step them round the body to then use a router or something to shave off the jagged outline from the outside?
I haven't worked it out exactly. Yes, the plan overall is that I will cut the top and bottom to the outline of the guitar and then use one of them as a template to clean up the side of the body, and so I certainly won't carefully pre-shape the curves in each piece. I do need to make sure that I won't reveal any gaps when I rout the sides, though, so I will need to make sure that I have nice, flat joints on all of the pieces, and they will need to be angled to follow the line of the guitar.

Yesterday afternoon I found an off-cut from an ebony fretboard which I carefully bandsawed into four thin strips which, after flattening (because the band saw is not very precise), will hopefully provide a thin layer between the two rows of bricks. This will help to compensate for any slight differences in height and remove the additional complexity of ensuring that all four bricks in both rows meet up exactly at a point, since the little bit of separation will distract from any small inaccuracies.

Today is a bank holiday here, and so I plan to get a good few hours of work done. Finishing the wenge 339 is a priority, but I'll probably do a bit on this one too. I need to work out what I'm going to use for the neck - I'm thinking of a laminate of sycamore and padauk, to give strength and match the sides, and also following the guideline of not using too many different woods. If I do that, then I should be at four - sycamore and padauk for the bricks and neck, zebrano for the top and back, and then whatever I decide to use as a fretboard.

Talking of the fretboard, it's a bit soon to make the choice, but I have a piece of something called "silky oak" which looks rather nice and might go well. It depends on whether the piece is big enough to get two fretboards out of it, though, because I'm mostly intending to use that as the fretboard on another lump of oak that will make a nice neck.

I'll probably post any progress later today! :)
 
#15
I did do some work on the wenge 339 today, but I also made some good progress on this one! The first job this morning was to draw a full-sized diagram of the guitar:
Drawing.jpg
The main purpose of this is to get the dimensions and break angle for the neck, which depends on things like the scale length and the height of the bridge. I also, in the bottom right, worked out the design for the neck.

Then I used my band saw and thicknesser to prepare the centre strips of zebrano and padauk. I only had one piece of sycamore that was long enough for this neck, and I needed to make a diagonal cut down the length in order to get the two side pieces. After some deliberation, I used my circular saw for this, which did a good job. It's a tool that you don't often use in guitar-building, but it solved a knotty problem for me today!

Here are a few pictures of the neck - firstly the woods (don't worry about the cut there, it will either disappear or be hidden inside the body), then pictures of the gluing and clamping. That's how it is now, and it will probably stay like that until tomorrow to make damn sure that it is well glued together!
Neck woods.jpg Neck gluing 1.jpg Neck gluing 2.jpg

If this operation is successful, that's a major step forward in this build. I'm looking forward to removing the clamps and seeing how it's worked out tomorrow!
 
#16
The gluing operation seems to have worked, so here are a couple of quick pics of the whole thing. There are two or three dodgy bits, e.g. where one of the pieces of padauk was too thin and left a gap, but they will disappear when the block is cut into the shape of the neck.

The next step is to square off the top and bottom, probably using my thicknesser, but it's very noisy and I got back too late this evening to do that.

Quick pics of the glued neck:
Neck glued 1.jpg Neck glued 2.jpg
 
#17
This weekend, as well as various other things going on, I have two goals for the 12-string. The second, for action tomorrow, is to take my neck blank and do the first cut down to the rough shape that it needs to be. The first goal has been achieved today, which was to design and cut the shape of the body in the top and back.

I used my PRS Custom 22 as the basis for the body shape, but I lengthened the upper horn by about an inch so that the strap button will be a bit further along the neck, which will help with the balance of the guitar since the headstock is going to be heavy with the 12 tuners. I also lengthened the lower horn a bit. I'm not worried about the extra weight of the slightly larger body because it's going to be largely hollow anyway.

I glued the top and back together (using the masking tape and superglue trick), then drew out the shape, used my bandsaw to cut close, then the spindle sander, and finally a bit of work with a sanding block and some 60-grit sandpaper to smooth out any irregularities. The spindle sander is great, but it can leave high or low spots, and I wanted to make absolutely sure that I have a good edge because I'll be using that as a pattern to trim the sides with the router later on.

I'm well pleased with the result, and keen to sort out the neck tomorrow! :)
Top & back shaped.jpg

Incidentally, I'm shooting some video of this build and plan to upload a few videos to YouTube. I think getting the neck shape roughed out will be a good place to end the first video, so I'll probably try to edit and upload the first episode in the coming week.
 
#18
Just a quick update today. After watching the rather boring Monaco F1 Grand Prix, I got back to work on the neck. I had marked out the required shape, copied from my drawing, and I embarked on a rather torturous process to cut it down. Because my bandsaw doesn't cut straight and wanders a lot, I drilled over a hundred guide holes before taking it to the bandsaw. That was all successful in that I didn't cut any bits that I didn't want to cut, but there was quite a lot still to take off. I did that mostly with my belt sander and shinto rasp, with a bit of extra help from my spindle sander.

The neck is now pretty close to the necessary shape. Next I need to fit the truss rod, and then choose a fretboard. I will probably leave that for a while, though, and make a start on building the sides of the body.

Here's a quick pic of the neck after today's very messy work - I had a lot of cleaning up to do after that!
Neck shaped 1.jpg
 
#20
I had a very productive weekend, particularly on Sunday. I managed to refine my technique for sizing and gluing the blocks so that I could do several of them without waiting for the previous ones to dry. Here's a picture of that in progress!
Clamping blocks 2.jpg

This meant that I was able, contrary to all expectations, to finish the first row of blocks yesterday, having glued more than three quarters of them on in one day. I did a few other things yesterday, as noted in the "smile" thread, but let's not go into them here.

This evening, after work and dog walking, I cleaned up the first layer of blocks in preparation for the ebony stripe that will go on top. I used my router to trim the sides flush with the body, and then smoothed the inside edges a bit - they will never be seen, but it would annoy me if I know that the inside is untidy!

Lastly, since the blocks are actually slightly different heights, I had to flatten the top, which I did using my Shinto rasp and sandpaper, checking it with a straight edge to make sure that it's reasonably flat overall. After all of that, it looked like this - note that the walls are thicker where the strap buttons will screw in!
Blocks layer 1 complete.jpg

I thought that was all I would do this evening, butI couldn't resist going a little further and gluing on the first pieces of ebony. I have some offcuts from a fretboard (it might have been johnniegoat's; I'm not sure any more), which isn't ideal because they are too narrow to cover the entire blocks, but I'll glue some other strips behind them where necessary to make a decent surface to glue the second layer onto. Each piece of ebony is about 3 or 4 blocks wide, and here are the first three being glued on.
Clamping ebony 1.jpg

I've actually glued about four of what I think will be about 16 pieces of ebony, so they should go on quite quickly.

Finally, here is the second episode of the build videos. I'm still recording part of what I'm doing, and the third episode will be all about this process of making the side walls.
 
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