Andyjr1515

Hi, John Always test first, but I've found the Ronseal Hardglaze (not Diamond Glaze which is their more available but quite problematic acrylic based (?) product) works absolutely fine on waterslides. To be honest, I never gloss the fretboards so I probably am not the best person to ask. However, masking frets would seem to be a pretty impossible thing to do so I would have thought that spraying and then scraping the varnish off after drying would be a more common way of doing it. Hope this helps Andy

With the main structural braces secure, I now am adding the side braces. Although these also help to maintain the spheroidal shape, their main function is to transfer the vibrations to the various parts of the top. These are the ones that will be tweaked during the tap tuning process. First thing after the glue is set, however, will be to slim down the cross sectional profile of the braces into the familiar arch shape.

I would be lying if I said I fully understood what exactly does what. But when I was considering building my first acoustic I did a huge amount of reading and internet trawlingof what the high end makers do. And then I went to a large guitar store and looked into the soundholes of a large number of steel string makes which bore out many of the things I'd read - that the great, great, great majority of steel strings are built to essentially the same formula I followed every single one of the common features to the letter. I was so pleased to have ended up with an instrument that actually held the tension of the strings that I'd have been chuffed if it had sounded like rubber bands over a baked bean can But it sounded brilliant! Like - better than my mate's Martin D18 brilliant!!!! So how many builders and manufacturers actually understand why these features work - and understand enough to know what to tweak and where to make them even better - is probably relatively few. I certainly don't. But they - and I, now - do know they do work. So, while most of my solid builds often go away from convention - and sometimes in a big way - for acoustics, I follow the formula slavishly. And the elements in that formula?: - Almost all steel strings use a dished top. There are only a couple of makers I know of who make a flat top - The great majority of them use this identical bracing pattern - even down to a tiny sliver you will see me put on top of the x brace joint - Even the position and height of the nodes on the braces are likely to be within a few mm of the same positions - The back and sides makes very little difference to the tone. It pretty much matters not what they are made from as long as they are structurally rigid enough. In many people's view, laminated sides and back makes no tonal or volume difference. - The wood type, grain, stiffness and thickness of the top wood makes a very significant difference to tone - As does the thickness and shape of the braces...which is where the black magic of tap tuning comes in (of which more anon)

Hi. No - not sure I've actually used Koa to be honest. Exciting project in mind?

No - it actually enhances it. And we get to get into the really black magic world of tap tuning... If you thought laminating was controversial.... I'll cover this soonish.

Indeed - I expect the tone will be completely wrecked OK - laminates (I prefer to call them scarf joints ) fixed means that the braces, fully shaped, now fit snugly in the radius dish: So with a final scrape of the top to get the harmonics back now the stiffer rosette is in, I can mark the position of the braces on the top: And then get out the SUPER HI-TECH GO-BAR DECK! Yes...your eyes aren't deceiving you...can this really be just two pieces of chipboard held apart by a quartet of threaded rods with the radius dish vaguely plonked on top. Yes it can! What's it for? Well, how else are you going to clamp down a set of different size braces across a .5mx.5m area, with enough force to press the top into the radius dish while securing all ends and middle of the braces for a strong glue joint....other than with something like a bendy dowel??? Aided and abetted by a few more bendy dowels and a herd of bendy fibreglass rods: And to everybody's amazement the first time they try this - it works!

Now then, I know what some of you are thinking. You're thinking - 'Yes - 25 feet is a tighter curve than you imagine. And surely he's going to run out of wood to get that X-brace to fit?' Which is why I'm splicing extensions to the four ends of the X-brace struts... Another one for the Andyjr1515 bloopers DVD, @LukeFRC ?

A bit of explanation in this post of some of the design and build features of a 'typical' steel string guitar for those who haven't ever built one but might. I stress that, after building only two acoustics before, I'm no expert but it's OK because experienced acoustic builders will have 'unfollow''d this thread long ago . In my defence, this is still firmly in the basics territory, but it is info I would have appreciated understanding prior to embarking on my own first acoustic build. First of all - what plan am I following? Got one of the Elite Guitar Plans because it was easier than printing off the numerous versions on the internet and stitching together so many A4 sheets. The design is the pretty ubiquitous one based on the Martin X brace design of yesteryear. The plan is pretty good too, other than the spelling. So the basics: The top is spheroidal, like a slice of a 25 foot radius football The braces not only transfer the string vibrations, via the bridge and underlying bridgeplate, to various regions of the top, they also form and hold the top in the 25' radius spheroidal shape. So the bottoms of the braces need to have a radius appropriate to were they will sit on the sphere And for that, we use the 25' radius dish again In pictures: First the braces are cut to profile. These are flat bottomed at this stage so allowances need to be made in terms of the thickness. I also leave them long so I can trim to my planned final length based on my actual sides assembly. The plan shows where each of the braces will be positioned: But, at the moment, they are flat bottomed - and they need to sit unstressed in their final positions in the radius dish so that, when they are glued down into the top - done also in the radius dish - they will force and hold the top in that spheroidal shape. And at the moment they don't...yet: It always surprises me just how curved 25' is! So - the next step is to curve the bottoms of each of the braces so that they sit in the dish with no gaps. Then we can reveal the black magic of the go-bar deck Hope that makes sense to those who are interested...

Yes - in a way a bit of a shame to lose so much of the figuring. It will be enhanced, however, when the finish is applied. Also it was too small a piece to use for the normal positions such as headstock plate, etc..

Onto the installation of the rosette and purfling circle. This is a bit scary because it's got to be spot on. And it involves routing a couple of mm out of a top that is only 2.7ish mm to start with! First was to use the asymmetric holes in the centre of the cut out rosette as the template for a couple of similar holes in the top: Then remember not to cut out the centre until I've routed all of the other bits! First I routed the edges of the rosette - the inner using one of the pivot holes and the outer rout using the other one : So - what's going on on the right hand side? Well - it's a good illustration of a little tip for acoustic guitar rosettes: leave the join lines / gaps and test the rout position always at the neck end of the circle. Why? Because that will be covered by the fretboard And so if you pink torpedo up your measurement, measuring from the wrong side of the router bit: ...then you can correct it for the full circle and the pink torpedo up won't show because the fretboard will be over it Anyway - trying to remember which pivot hole to use far which area, I indexed the router a couple of mm each time each way to clear out the wood in the centre so I could fit the rosette Then a 1mm slot on the outside for some purfling: Then installed the purfling - it bends easily round this kind of radius dry and cold - and then some very careful scraping to bring the whole rosette down to top level and finally a deeper rout to cut out the sound hole. And here we have it: It's lucky that the c**k up slot is going to be covered, otherwise I'd have had to have added another piece of laminate as a 'feature' But luckily, on an acoustic, the fingerboard (or in my case it will be a stick on end magnetic pickup from a Shadow dual system) goes right up to the sound hole: I've said it before. Many regular builders will agree that we still make as many c**k ups as when we were beginners - it's just that we get more skilled at sorting out the consequences and hiding them!

Ah....varifocals....love 'em

What? WHAT?? Damned varifocals!!!!!

So - time to add a swift: And then cut out the rosette ready for installing:

Well, scraped and a quick coat of tru-oil. Mmmm - that looks OK. Better not wreck it - Tasmania is a long way to go to get another piece!

Ah - OK. Thought you meant the fixing method. Yes - it's a bit of a departure shape-wise. So, you're looking for a straight (Gibson-ish?) stop bar but that screws in rather than sits on pegs? I'm slow, but I think I got there in the end

Very exciting that we have a new build on the board! Not sure what you mean ref the Warwick tailpieces using inserts, @Christine ? Presume you mean this type? https://www.thomann.de/gb/warwick_bridge_30118_4c.htm

Bit more progress in between the distractions of normal life! The second side of kerfing strips was completed: ...and then back to the top to get it down from just over 3mm to closer to its final thickness. My hand arthritis is causing me gyp at the moment so I brought out the Stanley No80 scraper plane into action. I'd forgotten what a useful plane this is! It made short but controllable work of the final thinning. After each pass, I picked up the top from an edge and rapped it with my knuckle. It had passed from drum thump to drum thump with one harmonic to drum thump and multiple harmonics - probably just going from 3mm to 2.8/2.9mm ish. Then one last pass and a change again - now even running my hand across the grain was making it ring out. So I've stopped. It's probably just under 2.8mm. Now I must stress I don't fully know what I'm doing on this sort of thing - I reckon to do that you have to sacrifice at least one top (or guitar) by taking it up to the 'oops - too far' - but I know from my last build that this is going to be strong enough and will be capable - if I get everything else right - of producing a nice sounding guitar. Here it is laying on top of the 25' radius dish: I was worried that the top might still be a little too stiff (and therefore too thick) but it presses into the dish no problem - the go-bar deck certainly won't have difficulties. What is nice is that for the last dreadnought I built, I marked the brace positions on the radius dish so that I could sand them to the correct radius for each position. One less job this time around Next task is the sound hole - but before you can cut the sound hole out you have to sort the rosette! A Tasmanian member of one of the other forums on a visit to UK a year or so back presented me with a few nice sample pieces of local Tasmanian wood and the challenge 'to incorporate this onto one of your builds.' Well - I reckon a book matched pair might do for the rosette! First I thicknessed it on my bodge-home-made-job thicknesser jig: That's gluing, then I can see if it will work OK as the rosette feature ring

I think the chequer looks different and quirky cool. But if it's lifting too much, it might start looking a bit naff. I'm a sucker for bright yellow and jet black but it's whatever you like, not necessarily what we like

Just had a look at the photo and can see that you are just covering three - sorry, misread your post. Yes - a low fret creates a high fret next to it, if that makes any sense. Do the rock test three at a time from the 1st fret to the end of the fretboard and jot down which frets rock. It may be that the fretboard needs levelling if they're all over the place.

Do the rock test only covering three frets at a time. If the credit card is too long can you use something else ( or cut an old card / store card etc)? If you can do that, then try 8 9 10 then 9 10 11 then 10 11 12 to see if you can work out where the issue is

Sounds pretty good to me.

^ I would have thought. Use the edge of a credit card or similar as a rocker to bridge across the 9th 10th and 11th frets and check if it 'see-saws' on a high 10th on the A string. If so just use a fine flat needle file in that area to take the high spot off (until it doesn't rock - don't overdo it) and polish it up with very fine wet & dry or micro-web to polish out any scratches. For a single high spot you can do this with the strings still on.

Yes you are right. The main thing is that the gluing surface - which is actually the kerfing strip - is acting as a proper mating platform.

And in the meantime, the first length of kerfing strip goes on. This is the strip that the top and back will glue onto. It is set a mm or so higher than the sides because the top and back will be dished - the kerfing will be sanded down in the radius dish so that is ends as a close fit to the dished top and back before gluing - I'll explain that better when I have some photos to illustrate it!

There are various ways of thicknessing an acoustic top. In the end, I used a similar method to one or two classical guitar builders I've seen in various places. Sounds surprising, but it uses a block plane! First cross grain, then diagonal and then with the grain: I did sharpen the blade before I started, and these are SUPER thin shavings, but this is the best surface I've ever managed with a block plane! This is straight off the plane: When I was about 3.6mm, I moved onto the scrapers. This is now down to 3.3mm and I will move to a large sanding block to drop it down to about 2.9mm. I say about, because I am using the tap tone approach (great video on one of Robert O'Brian's 'Luthier Tips du Jour' videos, although he uses a thicknesser sander) rather than aiming for a specific thickness. I will not, however, drop below 2.7mm tap tone or not!