Andyjr1515

Looks and sounds good @Sidlanir

OK - back in the cellar! I was going to start on the neck, but decided there were still some necessary things to do with the body before doing that. The reason is that, with an acoustic instrument, the neck angle is pretty much fixed at the initial build - and it has to be right. And to do it you need the actual neck. But you also need the mortised body. And so you need (at least) the top on. So back out came the 25 foot radius dish - and this time with some emery cloth double-side-taped to it. This meant that I could sand the slightly proud linings (yes, @Si600 - being made out of fine worsted wool they would be proud ) to a gapless fit with the spherical top: Then a double check inside and out that there is a good, tight and glue-able fit: Then likewise with the back - MUCH easier to do this before the top is glued on: Note above the notches in the linings where the main X-brace and cross-brace will tie into the side/top joint. And finally, after double and triple checking, the top is glued, using as many spindle clamps as I possess and clamping cauls to spread the load: For reasons I will explain later, I will be breaking convention and NOT glue the back on at the moment. Breaking this convention is something I tried on Matt's Dreadnought build last time and it gives distinct advantages. So the back won't be glued for a while yet

Fascinating. Real blue-sky thinking

There's some nice figuring in that body wood. Looking good

Czech Republic to be specific I didn't think it would be so difficult to get hold of 7mm ebony dots!

I recently did a veneer job for Rog (see Build Diaries) and presumably it was an OK job because he entrusted me with his BEAUTIFUL Bass Collection 4-string to do something really scary! Changing retro-fitted Abalone dots for some ebony ones to get it back to as close to 'dotless' as possible! Here were the dots (the photos are a bit out of sync): This is not a difficult job - but it's not for the faint-hearted. Or for those who don't sharpen their chisels properly I only started taking photos after I'd already got one out - so ignore the missing dot in this shot. First task is getting a dint in the exact centre of the shell. I use a very sharp-pointed punch: Then a 1.5mm drill in the centre dint. (I told you the photos are out of sequence...here you can see the sharpie blackness Rog has been temporarily using on the other abalone dots): Then the slightly scary bit - both for the owner and for the modder...especially if they value their bradpoint drill bits - drilling out the shell! : Which gives you the new chambers: Which you fill with some ebony dots, wood-grain aligned and glued with epoxy mixed with ebony dust: Then trimmed flush with super sharp chisels: Scraped flush with single-sided razor (actually held in both hands): Which takes off all of the previous finish and therefore has to be done for all fret positions for an even finish: Followed by a fine sanding with a piece of scrap maple high-precision mini sanding block: And finished with a whisper of good quality danish oil to reseal it all: And lastly go and buy a new brad point drill

Modest progress this week but next week should be back and steaming There is a fair bit done in terms of neck planning - although nothing to physically show yet - but I have now finally finished all the Go-bar deck stuff with the installation of the soundhole reinforcement. I've gone for a maple triangular strip with the curves filled in with mahogany: When this is all rounded off, there should be a light/dark/light pattern from the players point of view, coordinating with the rosette. Leastways, that's the plan. So the Go-bar deck can now be disassembled and put back in the corner but the radius dishes have one last use - sanding the over-size linings ready for the top and (eventually) back to be glued to. I'm really pleased with the tap-tune result for the top, so last thing to be done on the top itself before gluing the top onto the sides is just to finish sand all of the braces from their present rough-carved state

Both sets of braces are still in the 'rough carve' state but functionally are all now in place. The reinforcement strips that will go round the soundhole are just that - they won't affect the shape or the tone: And - although this is still a huge amount of tasks away - at least it's starting to look like an acoustic body:

And to the back. Again, the braces are shaped to the radius dish - this one being more curved at 15 feet radius - and then pressed into the back in the radius dish while gluing: Then, after initial shaping of the brace ends, a cross-grain backer is glued over the back join line: If you remember, the back had the splits in the grain. Well, so far - and this is the time it will expose itself - there has been no tendency for the splits to lengthen. And that is a very good sign. It indicates that the splits were in the bulk timber before cutting and not a spreading stress crack. I'm happy with that

It was a really nice bass

No - it's a 600mm wide slice off a 25 foot 50 foot sphere and so is a couple of mm deep

And here we are with the braces as fettled as I dare. Certainly there is a pleasing variety of tones across the various points and so I think this is the point to stop: Note that the main cross braces and the horizontal one next to the heel block all will lock into notches that will be cut in the lining but that the ends of the slimmer 'tone bars' fizzle out into nothingness at various places. There will be some thin reinforcement strips around the back of the soundhole but my attention will now be turning to the much more straightforward braces to go on the back. And for that, out comes the 15 foot radius dish. Yes - another radius dish! There are some scary bits with acoustics (and most of them are still to come!) - but there is something deeply satisfying about the above

And the braces are on ready for fine tuning I've roughly profiled the cross sections to a more triangular/parabola shape. Next steps will be to add the maple bridge plate and there is a small strengthener that goes across the X brace centre joint. Both of these make a difference to the flex of the top and so need to be in place before I do the final tap-tuning. Having said that, it already is returning a wide variety of notes and harmonics, which bodes well

Hi Richard Not too difficult. Just some mathematics to work out the depths at a series of radii, a router on a radius bar to rout the contour depths and then a curved cabinet scraper to join up the contour lines. The challenge was the dust. I could not believe how much dust was created - and mdf dust is pretty dangerous stuff...

I'm really not at all sure. The engineer in me says that it creates a tension in the top woods and that increases the harmonic potential (it is the harmonics from the top rather than the basic 'drum' pitch that seems to sort the men from the boys in terms of acoustic guitar quality). But the pragmatist in me says that I'm just going to follow what the majority of the best builders do

And while the bracing is drying, there is time to start putting the linings around the edges of the body sides. These held strengthen and stiffen the body but their main function is that the top and back will be glued onto these. While the edges are also glued, those joints will actually be routed away to fit the binding on the external edges. The kerfing (the saw cuts) allow the linings to bend round the fairly tight bends of the sides. The clothes pegs with stiff rubber bands wrapped round provide more than adequate clamping all the way round while the glue dries. At this stage, the linings are set a mm or so proud of the sides because - on account of the top and back being spheroidal - they will be planed at an angle and sanded in the radius dishes to produce a good fit all the way round prior to gluing.

I don't know why it's called a Go Bar Deck...but it is. Basically, two pieces of chipboard held apart by some sturdy bolted treaded rods; the radius dish placed on the bottom; flexible rods (the Go Bars) pressing down the curve-bottomed braces into the radius dish while the glue dries: And here are all but the last four small braces. This will be left overnight for the glue to fully cure and dry and then I'll add the last four braces. And then we will have a subtly spheroidal top ready for the braces to be slimmed in cross section - and then the tap tuning can commence

Actually, that is the next but one step after this - the dark art of tap-tuning...

And so to the top bracing. The Bouzouki is based on an OM acoustic guitar and the bracing pattern will be identical. And it's all a bit precise. Legend has it that Martin in the thirties (?) did a bracing pattern that just, well, worked. And from that point 90 odd percent of acoustic guitars have been, and still are, made with the exact same bracing pattern. I may well have my facts wrong but my philosophy is that - like banging dustbin lids to keep the elephants away - it works so that's what I'm going to continue to do! So, for those who haven't seen an acoustic build before - a flat-topped acoustic generally isn't flat. Most have a spheroidal shape of around 25 feet radius for the top and 15 feet radius for the back. So you have to make (or buy) a 25' and 15' radius dish, you have to curve the bottoms of the braces and then you have to press the braces into the dish to force the flat top into the final spheroidal shape. The process will become clear soon (probably tomorrow), but today I was cutting the braces blanks for the top. This is a straight piece of spruce sitting across the 25' radius dish: It's subtle. But the bottoms of the braces have to be planed and sanded into a curve - and because it's a sphere, the actual curve needed is different depending where each brace is going to fit. First is the well known 'X' brace which is two pieces curved underneath and locked together: And here it is in position on my home-made MDF 25' radius dish. Difficult to see, but both lengths are now completely gap free on the dish: The braces will have a LOT of work done on them, but it makes it a lot easier to remove some of the bulk by starting to cut them to side profile, especially in terms of the positions (again, very precise) of the peaks you can see below - the 'nodes'. Here we now have all of the braces for the top, rough-profiled but finish-fitted on their under-sides to suit the radius dish at each of their respective positions: And tomorrow, these will be glued and pressed into the radius dish to form the basic top shape. I might do some work on the cross-sectional profile of some the braces before they are glued in...I'll have a think about the best way round to make the access for the final shaping of the braces as easy as possible.

Absolutely. Life, as they say....

And we're back! The rest of the wood has arrived And based on the size of the bill...and our last Sainsbury's one too...I think that the Bank of England might be right about the economy heading towards a 'V' bounce back in a number of business sectors!!!

Somehow missed this! Looks great

Yup - looking really good

Superb, @Si600

Well, still drumming my fingers waiting for a nice big parcel of wood to arrive. So the only thing I've been able to do in the past couple of days is plane the back down to finished thickness (around 2mm) and cut out the oversize shape. So a subtle change from the previous photo but, heck, progress is progress! Workshop's a bit tidier too