Finished! A Guitar Bouzouki - yes, quite!

Andyjr1515

And yes - before someone asked me to make one, I never knew such a thing existed!

Anyway, they do and - for better or for worse - I'm making one

So the basic spec is:
- Irish bouzouki tuning and strings - 4 pairs of doubles in 1 octave below mandolin tuning
- OM acoustic sized body, but with neck joining at 16th fret - same bridge position, etc, so upper bout is 2 frets shorter
- Acoustic guitar-type bridge
-  Spruce top / Redgum (Satin/Sweetgum) walnut back and sides / maple neck with walnut centre splice / Macassar ebony fretboard
- K&K Pure Mini pickup
- 25.5" scale

I started on this a few weeks ago so I'll update progress so far over a couple of posts and then back into 'real-time' .  I'll whistle through the progress to date but if there's any area anyone wants a bit more detail if you fancy trying an acoustic build, then just shout!


I still had the old plans form the OM acoustic I built a number of years ago and so, using the basic main-bout shape and bracing pattern, I made some adjustments to the soundhole and the smaller bout from the waist to the neck joint:
 

I got a back and sides set in the redgum walnut that looked like it would fit the bill.  The yellow marks are splits (properly marked up by the supplier) and yes, there are some in the main area.  However, with the cross bracing helping to prevent those splits going very far, I think this is going to be usable:



I jointed and glued the spruce top and then thicknessed it down to around 3mm.  I then bounced a few rosette ideas to P, who this is being built for.  We settled on this:




So armed with my Dremel and the standard radius jig, I marked the centre points:



And then drilled those points for the radius jig spike and routed first the curves and then joined them up using the Dremel in the precision router base and a beam as a straight edge:


I then routed out the area where the rosette infill would go and bookmatched some offcut from the back and sides wood:



Next, I sanded that to fit and a recut the purfling strip slots and fitted the purfling as the joint lines:



Finally, cut a mother of pearl swift (my logo) and routed the recess for it:


And finally, fitted the swift, sanded it smooth and then cut out the soundhole:


Next post will be making the body mould and bending the sides









 

WezV

That's awesome!

barnstorm

Very cool project - thread bookmarked. Nigel Forster makes some lovely guitar bouzoukis if you’re interested in having a look at someone else’s.

TTony

Wow.

And now for something completely different ...

Love it. 

Andyjr1515

barnstorm said:

Very cool project - thread bookmarked. Nigel Forster makes some lovely guitar bouzoukis if you’re interested in having a look at someone else’s.

Thanks!

Yes - found him.  I think the guy who has asked me to build this one mentioned his name and I certainly came across him when I googled 'What the heck is a Guitar Bouzouki??'.  

But once you realise there is such a thing as a Guitar Bouzouki, you also find out there are more builders around than you could imagine   Forster, Stefan Sobell (I think that's the spelling), Osborne and I'm sure there are more.  There are some great builders around.     

 

 

TTony

Andyjr1515 said:

But once you realise there is such a thing as a Guitar Bouzouki, you also find out there are more builders around than you could imagine 

http://www.paulhathway.com/bouzouki-guitar/

Paul is a really nice guy too.  I took a trip out to meet him one day, and naturally came away with one of his creations!

Andyjr1515

WezV said:

That's awesome!

Thanks

Andyjr1515

TTony said:

Andyjr1515 said:

But once you realise there is such a thing as a Guitar Bouzouki, you also find out there are more builders around than you could imagine 

http://www.paulhathway.com/bouzouki-guitar/

Paul is a really nice guy too.  I took a trip out to meet him one day, and naturally came away with one of his creations!

There are all sorts of nice instruments on that site, @TTony ;

Andyjr1515

Next job was making the mould.  I used plywood and tried to remember where I generally clamp so that I could get easier clamping by having uprights in the appropriate strategic positions!



I also kept the inner offcuts which proved to be useful!


Next was to work out the shape of the sides.  The top will be dished to a 25 foot radius and the back to a 15 foot radius.  But the back also tapers from around 110mm at the back to around 90mm at the heel - and because of the curve of the sides, that is not a straight line as far as the sides go.


CAD would do this in minutes and - if I could remember my technical drawing - it could be worked out geometrically.  But I went for a different approach.

Here I add my normal warning:  happy to show you how I do stuff and why, but NEVER assume that this is how it should be done!


I cut a cartridge paper template and fitted it in the mould:



I got my levelling beam and packed it up to the required maximum and minimum heights:


I then ran a steel rule at 90 degrees down the beam and marked dots where it met the template:


Joined up the dots and cut along the line with scissors - as you can see, this is far from being a straight tapered line - it's more like a very stretched out 'S':


Near enough at this stage:




The sides were slimmed down from 4mm to around 2mm using - in the end - a block plane (which are not supposed to be the best thing for this job, but I found it easier than the Stanley No5, my Stanley scraper plane, cabinet scrapers, sanding...I tried them all ) and then cut to the above shape ready for bending:

 

paulnb57

I just love watching your builds Andy, I like the shared thoughts and processes and of course the final results! Top stuff!
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Eeewww was that a bit gushy?
  

Andyjr1515

paulnb57 said:

Eeewww was that a bit gushy?
 

Yes, a bit...but don't worry, it's only lockdown.  We'll all be back to hurling insults at each other before long - and oh how I look forward to that bit of normality  

Andyjr1515

And so to the bending.

 Here's my bending kit:



From the back:  Electric bending iron; water spray bottle; mould; thick gloves; brainwave - the kept inners from when I made the mould.  I just stacked them together and put them in the bench vice.  Might be useful


First, the side pieces were given a thorough soaking in the bath and then the hand bending began.  Walnut is usually OK for bending - keeping it damp and applying (quite a bit of) pressure, moving it slowly to avoid scorch marks, until you feel the wood relax while always listening and watching for the very first signs of any fibres starting to split.
  Worst case is when the whole side suddenly fails and then it's a complete new back and side set as they come as a matched set.  

The area I was most bothered about was that very sharp waist bend.  I turned the iron round to get at the tighter radius side:



  I took my time and could get to around 15 degrees short, but it wasn't going to go any further.  Then the inspiration of keeping the mould offcuts I kept paid off.  I could do it like a Fox bender...but without the heating blanket.  I got it hot on the pipe, made sure it was pretty sodden and then popped a lath on and gently clamped it.  To my relief and astonishment - it worked!




So the sides clamped in the mould overnight until they were completely dry:



Then trimmed the overlaps and added the tail and heel blocks:


And, although the addition of the kerfed linings that will go along both edges will stiffen it up properly, it will already pretty much hold its shape:


And that's pretty much up to date.  The wood for the braces, kerfed linings, bindings, bridge plate, neck and fretboard are on order from David Dyke and then the dishing, bracing and tap tuning fun can begin

  
  

MattNovak

Another interesting one to follow! I assume the build updates aren't in real time?! It makes my progress today look glacial  

Andyjr1515

MattNovak said:

Another interesting one to follow! I assume the build updates aren't in real time?! It makes my progress today look glacial  

Not the above - that's about 2 weeks.  From now on it will be real time so yes, probably the same

Andyjr1515

The wood has arrived and so progress has been able to recommence!

I started the fitting of the kerfed (slotted) linings.  These are set proud of the sides because they will be sanded to shape to get a good fit when the top and back are ready to be fitted:
 

Did I steal the clothes-pegs-with-rubber-bands from someone here? 

Then top braces...

The tops of most 'flat-topped' acoustics are, in fact, spheroidal.  Typically at 25 foot radius.  So basically, you make a dish with a 25' radius, you curve the bottom of the braces to that curve in the positions they will sit at on the finished top, and then when gluing, you put the top onto the radius dish and press the braces down to force the top into the 25' spheroidal shape.

And 25' is a subtle radius.  The shadow makes it look more of a curve than it is - the radius stretches from either side of the straight bar in the photo, so a couple of mm over 600mm or so:


The bracing pattern is identical to the OM I built a few years ago and uses a very standard 'X' brace pattern.  An the X brace is the first thing to get right:



With the undersides of the rest of the braces curved in their respective places (rough shaped with a block plane then some sandpaper at the appropriate positions in the radius dish itself), a final check that they sit in the dish completely gap free, and then it's time to get out the home-made go-bar deck where I can use dowels and fibreglass rods to force the gluing braces down into the top to create the spheroidal curve:



And we have a shaped top.  The braces are slimmed to their triangular/parabola shape ready for the next stage, once I've added the maple bridge plate and x-brace joint reinforcement - the dark art of tap tuning!


What is encouraging is that the top is already ringing out with multiple fundamental notes and harmonics.  Fingers crossed
 

Creed_Clicks

These sound fantastic. Can´t wait to see the result.

Andyjr1515

Creed_Clicks said:

These sound fantastic. Can´t wait to see the result.

Thanks!

So - tap tuning.  What is tap tuning?  Well, tap tuning process is a process of changing the flexibility of top so it is capable of resonating - somewhere on the top - with every note that is going to be played on the instrument.  Leastways, that's the theory.

So when you are tap tuning, you are tapping the top in various places listening out for the fundamental drum note but also the ringing harmonics.  In crude terms, the more different notes and harmonics you can hear, then the more even and clear the instrument will play.  And there is a process of very subtle slimming and reshaping of the braces to try to make the bass side more flexible (and therefore resonate with the lower notes) the treble side a touch stiffer and the whole top to start resonating with multiple harmonics identifying the various notes.

Folks who know what they are doing, know where to fettle and by how much to identify any missing notes and tease all of these harmonics out.  I, on the other hand, just do as best I can in my relative inexperience and ignorance!

The best video I've come across is this one - IT GOES INTO A LOT OF DETAIL BUT THE LAST 20 MINS OR SO HE DOES IT FOR REAL.  The nice thing is that he lets you hear what it's like before he starts and what it's like when he's finished.



Mine, when I've finished, generally sound sound like his do before he's started

Nevertheless, a deeply satisfying process:


Just got to put some reinforcement around the soundhole and I then can get the second radius dish out - 15 feet - and move to the bracing of the back

WezV

The advice I got was that it's worth doing, even if you are not sure what you are listening for yet... It's just about getting familiar with how it sounds at various stages of the build, and beginning to understand how that translates to the finished instrument.

Andyjr1515

WezV said:

The advice I got was that it's worth doing, even if you are not sure what you are listening for yet... It's just about getting familiar with how it sounds at various stages of the build, and beginning to understand how that translates to the finished instrument.

Yes - indeed. 

I have got to the stage of being able to recognise when I have got tap tones I need and when I haven't and also the principle of how to develop, say, the bass  or the treble.  But quite where to adjust...and more to the point just how much - is still very much guess work and the occasional lucky break.  The last dreadnought came out remarkably well - but probably more luck than judgement.

If I judge that I'm going to do many more acoustics, then I think I will indeed invest in the time to make three or four tops and fettle them to past the good tones and down the other side back towards dullness just to see where that happens.  I think at the moment I tend to stop short of the full potential that the wood is theoretically capable of. 

It's great fun, though and very satisfying when it sounds tangibly better than a piece of string stretched over a baked bean can

prowla

Cool.

Not quite in the same class, but I did a conversion of a kids guitar to a mandolin (aka mandotar), but then I tuned it like a guitar so I wouldn't have to learn new chord shapes.

Andyjr1515

Looks good @prowla ;