Published On: Wed, Mar 11th, 2009

Repairing the bridge and other useful tips on servicing your guitar.

Having issues with your Guitars performance?.See how to deal with Tuning, Truss Rod and Bridge problems. We cover all aspects of using our in-depth guide and little care without resorting to expert attention.

This Burns Vista-Sonic is a fine, chunky ’60s model with many of the features that make Burns guitars great – but I doubt you’ll be surprised that this one has a whole load of tuning problems that need sorting so that it can live in the modern world.
Where to start? Well, let’s begin the list of jobs from the top. The zero fret has been stoned down flat at some time, along with the frets. This will effect the intonation, since the point at which the strings leave the zero fret has been moved forward: it should leave from the centre of the fret, not the front (ideally, of course, the zero fret should have been removed before the other frets were stoned). Next, the floating tremolo has been badly set up. The plate the saddles sit on should move backwards and forwards smoothly; here, however, it has moved further and further forwards, so that now the rollers that hold it down are only working on the back edge of the plate (see pic 3). This means the back edge of the plate is coming up as it goes around the rollers rather than back and forth on a flat plane, and the front is hitting the scratchplate. We need to get the plate back and the saddles forwards to correct this. Oh, and the front edge of all the saddles are badly worn; the strings are not going over them cleanly, and they’re incorrectly spaced.
First, off with the strings. You can see this is a left-handed guitar – hence the big reminder note I’ve put on the headstock! You’ll get a bemused look when you hand back a guitar that has been set up for a right-handed player to a left-handed player, so this should remind me! The first job now the strings are off is to grease the tuners. Tuners are very often replaced when all they actually need is cleaning and lubricating; these are original so we want to keep them, and a spot of grease should keep them going for years to come.
The bridge on this guitar actually fell out when all the strings where removed since the screw holes were all worn. I’ve shaped some softwood splints to fill the holes – remembering to work away from myself with the cutting tool to save my fingers in case anything slips – and I’ve glued them in. When they’re dry, we can re-drill the holes.
Before any work can be done on the saddles the screws that adjust the saddle heights will need to be freed up. I’ve not even tried adjusting these yet, as years of sweat will almost certainly have corroded them. We’ll soak them in some thin oil first, as this will give us the best chance of not rounding off the inside of the Allen key holes.
While the glue is drying and the oil is soaking in, we can get on with the zero fret and the frets. The zero fret is too flat and too wide, so I’ve decided to take it out and replace it with a narrower one to make sure the string will leave at the correct place. Rather than hammer it in, I’ve decided to use a fret press to make sure that it’s seated evenly and correctly. The rest of the frets show very few signs of wear, so I’m just going to adjust the truss rod and see if I can get the neck straight. If all the frets are level then I won’t need to stone them – I’ll just re-profile them with a fret file.
Burns guitars used an ingenious truss rod system, and you’ll be able to see from photo 12 that the adjustment is on the underside of the neck. It is possible to use a socket to adjust it, but I find it a lot easier just to take the neck out – especially if you’re unsure of the correct size. With the neck adjusted correctly, all that’s needed is to re-profile the frets using our fret file, first with some 600 grit wet-and-dry wrapped around it, and then moving on to some finer 1200 grit to polish them up.
On to the next tuning problem: the saddles are all worn, and they need filing down and re-profiling. I’ve chosen to remove each one at a time and to replace it before moving on to the next, as this will keep them all in the correct position. It’s a good idea to hold them with a clamp while working on them, as this makes things far easier. I’m using a fine Swiss file to re-profile the surfaces, and once I’m happy with the shape I’ll polish the surfaces with some 600 grit wet-and-dry. When this is done, we’ll have six saddles all with nice smooth surfaces for the strings to pass over.
It’s time to start work on the vibrato. On the base of the vibrato unit there’s a spring which counteracts the tension of the strings, and this needs to be balanced so that the vibrato arm is in the correct place: at the moment it’s hitting the bridge plate. To move the arm out we need to put more tension on the spring; this will pull more against the strings, bringing the arm further out. Trial and error is the only method here. It’s best to move the screw out maybe only half a turn at a time, and you might have to remove the bridge and adjust the screw a number of times to get it right.
The bridge plate moves over the roller at the front and under the bearings at the back, and the bearings need to be greased and the surfaces cleaned, along with the front roller. Any bits of dirt between the roller and bearings will affect tuning stability by stopping the plate moving freely and returning to where it should be.
Before the bridge is screwed back on, make sure that the earth wire is in place. This needs to make contact with the underside of the bridge, which should be cleaned with some glasspaper to make a good contact. Without a proper contact the strings will act as an antenna and pick up just about every sort of interference.
Before drilling any holes on guitar bodies it’s a good idea to measure the depth of the appropriate screw and then transfer this over to the drill bit with a piece of tape. It’s a great way of avoiding drilling all the way through the guitar! Also, remember to put some candle wax on the screws beforehand. This will help them both on their way in and on their way out.
So now we’ll put the bridge back on and fit a fresh set of strings. Curiously, the slots in the nut behind the zero fret are not deep enough: they should hold the strings to stop them moving from side to side but not hold them off the zero fret, so each is deepened in turn.
Inevitably, it turns out that I’ve wound the screw on the tremolo out a little too far, so now the trem arm is sticking out from the body too much – so it’s off with the bridge plate yet again, and I can wind in the screw which will put less tension on the vibrato. It’s taken three attempts to get it right. You can see from the picture that we have now moved the plate back from the scratchplate; the bearings are now also firmly on the plate rather than the back edge, and the strings are all in the right place.
It’s worth mentioning here that I’ve set the guitar up with 10 to 46 gauge strings. If you decide to move up to heavier strings then you’ll put more tension on the vibrato and move the arm further forward; with lighter strings, it will go back. So before you go through all this trouble, make sure you’re working with the strings you intend to carry on using.
Now we’ve replaced the zero fret, re-profiled the frets and moved the saddles, we can set the intonation. Again, choose your gauge and brand of strings carefully now, as not only does the intonation on each string vary from gauge to gauge, but it also varies also from make to make. As ever, if a note played at the 12th fret is sharper than the 12th fret harmonic then the bridge saddle needs to go back, if it’s flat then it should go forwards.
In summary, I must say this vibrato is one of the hardest to set up that I’ve come across! If all the surfaces aren’t flat and everything isn’t working smoothly, then the guitar simply won’t stay in tune. Still, working on the vibrato, making sure the strings leave the zero fret properly, and checking the frets and the saddles has resulted in a guitar which performs really well. A lot of work… but definitely well worth the effort.




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