Second-hand acoustic guitar setup

Subject: Tech: Second-hand acoustic guitar setup
From: Richard Bridge
Date: 11 Feb 21 - 12:59 PM

I assumed there would be a thread about this possibly contentious topic, but I can't find one.

So, my ex is in DRC and has only a pretty crap old guitar to play. She has just stripped one machine head and I have sent four similar to the lady who assembles the aid parcels we send her (to keep a long story short). Putting that on should be easy, and it's urgent because some ppl with cameras want to record her for their video channel and possibly broadcast.

Her father bought her the guitar when she was previously out there about 8 years ago and when she went back about 1 year ago and retrieved it, it seemed it had been unsympathetically stored in the humidity and heat of Kinshasa. She has been saying "it twangs" but is not giving us any better clues - her use of English (which is her first language) is charming but idiosyncratic.

So I am guessing a root and branch setup is necessary. She has not got and cannot access sophisticated tools, and shipping a whole toolkit from the UK would be prohibitive and the best bits would probably get nicked at customs. So I'm going to have to talk her through this in Whatsapp video calls, and I am not really an expert. So if a real expert wants to correct my advice - here it comes!

First measure the action at the 14th fret (the body join). If it is higher than 2.4/1.8 mm there WILL be work to do.

Then capo at first fret and put bass string (and each in turn) to the 14th fret. What is the clearance string-to-fret at the 7th fret. It's summer out there now so aim for 0.25 mm - the truss rod will shrink a bit in their winter. But not a lot as it is very nearly on the equator. Adjust with truss rod, remembering always to finish while tightening, not loosening.

I bet the frets are all over the place. And no she has not got a fret rocker but I am sending her a neck beam and emery cloth. Remove strings, and carefully check the neck by eye. Set it DEAD flat using the truss rod and Mk 1 eyeball. Gently tap down all frets. No she has nt got a fret hammer, but a bit of wood or a couple of layers of Elastoplast and GENTLE tapping with smallest available ordinary hammer will do. Run superglue - as little as possible - along every fret. Now they will not move even in that climate.

Using neck beam and emery rub down the entire lot of frets. That's why the neck had to be set flat. If there is lots of playing wear do not take the grooves right out or you will be left with no frets! Return forward relief to 0.25mm.

The frets will now be flat-topped, a bit. No I am not sending her a crowning file, I've seen too many people over-round the fret ends so that the strings slide off the side of the neck. Protect fingerboard with metal protectors (bits of brass with slots in that fit between each fret and the two on each side), And by hand emery each fret across the neck to take the sharp edges of the tombstone shape - slightly rounding the fret top.

Now lower (almost certainly) the saddle to get the action at the 14th fret just a smidgeon over 2.5/1.8. If it's too low cut a strip off an old credit card and put it where an undersaddle pickup would go. Sanding a saddle down much is very boring! But it has to be right and the bottom of the saddle has to be flat. It's easiest if you have a small vice so you can file across the jaws - but she has no small vice and no suitable files, so the neck beam and emery will have to do.

And finally the nut. Put the OLD strings back on (you are about to wreck them). Capo at first fret. Measure action at the second fret. This requires critical accuracy. Take Capo off. Compare action at the first fret to what you just measured on the second fret. You want them to be the same (unless you play with a pneumatic drill and a number 12 woodscrew) - maybe leave 0.1mm on treble or 0.2 mm bass as a safety measure. Use an old hacksaw blade sideways across the neck (packed up with enough gaffa tape) to prevent over-cutting, and file the nut slots to the right depth using nut slot files (which I am sending), Be careful to make sure that the file angles down a bit towards the headstock but not too much, so that the string is in firm contact at the neck side of the nut (so the string length is correct) and also at the headstock side (or you will have a mystery buzz that is hard to trace and eliminate).

Hunt for the softest lead pencil you can find and try to get some graphite in the nut slots to reduce clicky tuning.

Put old strings back on and compare by judicious pressing down of strings at the first fret and the second fret the height of the action at the first and second frets - each first fret should be hardly any if at all higher than each second, and the heights should progress evenly from the bass (highest) to the treble (least). Adjust with not more than one stroke of the slot files each time. This is where you wreck the old strings pulling them out of their slots one at a time and parking them in the next available slot to allow you to do that very careful filing. Do not rush. It is very easy to overdo this. And if you do you will need either a new nut or to remove and pack up the old one!

Re-string, out there preferably with 11-52 or 12-53 Elixir Nanowebs

Over to the experts

Subject: RE: Second-hand acoustic guitar setup
From: GUEST,#
Date: 11 Feb 21 - 01:19 PM

Jean-Luther Misoko Nzalayala (Socklo) should be of some help, assuming he's still doing guitar repairs. And from what I can determine he's in Kinshasa.

Subject: RE: Second-hand acoustic guitar setup
From: Richard Bridge
Date: 11 Feb 21 - 10:22 PM

Indeed, Guest, I believe that he is, but the articles I have found on his work do not seem encouraging, if what one is seeking is the sort of guitar that we would aspire to in the UK or USA. There are I think two guitar makers in Kinshasa but there are two or three potential problems with going to either. First one could easily be writing a blank cheque, and second there are considerable risks in getting around in Kinshasa without ones own car and an armed guard. Third there is the apparently usual lack of urgency in the DRC. My ex has been trying for some months to find a vet to spay two kittens that she has rescued - but apart from one totally astronomical estimate responses to enquiries simply do not happen.

Subject: RE: Second-hand acoustic guitar setup
From: GUEST,James Phillips
Date: 12 Feb 21 - 03:14 PM

I know this has nothing to do with the actual setup and work that needs to be done, but I just wanted to point out that if after all that setup the intonation is still less than ideal, I have had good results by using the so-called "sweetened tuning" championed by James Taylor (and now incorporated into a setting in Peterson strobe tuners). You detune each string by a few cents (different amounts for each string). It does a good job of evening out the intonation problems across the whole fretboard so that it sounds passable everywhere. Many a problematic vintage guitar has been made playable again because of it. You'll find the specific cent amounts if you Google it.

Subject: RE: Second-hand acoustic guitar setup
From: Richard Bridge
Date: 12 Feb 21 - 09:30 PM

Yes, I have come across it, but I am not a convert. In my experience (and my guitar fettler's experience) if the action height is right and the bridge compensation is right (which can be fun on a 12-string) altering string length a the nut end is usually not necessary and can be counterproductive. Now what is the other name for that? Was it not one of Zager and Evans who really used to champion it?