How to Make Your Guitar STAY in Tune

If you have clicked to this article, then I suppose you have a guitar that is causing you aggravation because it won't STAY in tune. It probably won't tune up easily either. We can make both of those problems go away. We are not talking here about a guitar that won't PLAY in tune. That's a different set of problems and a different article. Here's how to deal with this particular problem.

Things You'll Need

• The work described below requires at least a couple of files, a small, fine, three cornered file, and a small, fine, round file. In addition, you will need sandpaper of about #400 grade for polishing

Instructions

1. First, a little analysis of why the instrument won't stay in tune. The fundamental cause ALWAYS comes down to the same thing. For some reason, the tension is not evenly distributed along the string. Consequently, as soon as you pick or pluck or disturb the string in any way, it redistributes the tension and changes pitch slightly. It goes out of tune. If you could somehow pull the string up to the right tension and then weld it down to the bridge saddle on one end and to the nut on the other end, there would be only one section of string and it could not change. That wouldn't work very well because every time the temperature changed, so would the string tension, but that is essentially what locking nuts and tunable bridge configurations try to accomplish. If the instrument has a vibrato tailpiece, the situation just becomes six times as difficult. The following steps will solve the issue as far as is mechanically possible.

2. The string is divided into three or more sections on almost all guitars. The ball end or loop end of the string has to attach to the body somewhere. Then it passes over the bridge, usually with a fairly sharp angle. The active, vibrating part of the string stretches up the length of the fingerboard to the nut where it again makes a small (usually about 15 degree) angle and then proceeds to the tuning peg. It passes through a groove or slot in the nut and that is typically where most of the problems originate. When you tighten the string with the tuning machine, it tends to cut in and bind in that slot or groove in the nut. Often you can hear it creak and pop as it alternately tightens up in that first part of the string and then slips in the nut, transferring that tension to the remainder of the string. Sometimes on a round-hole flat-top acoustic, the ball end will give under the peg where it goes through the body behind the bridge. Regardless, the solution is to bring the whole string up to the same tension. Let's start at the top end of the guitar first, because that's where most of the troubles are found.

3. Most guitars have slots cut in the nut through which the string must pass. Those slots are theoretically the same size as the string. The string must put some downward pressure on the nut and then pass to the tuning peg. On many Strat-style solid body guitars with bolt on necks, there is not enough angle available because the neck was machined out of a single piece of 5/4"maple, so the string must pass under a hold-down Tee to get sufficient pressure on the nut for good sustain. That is another place where the string will bind. In my opinion, the nut of the guitar should have grooves only deep enough to prevent the string from jumping out sideways-no deeper than the thickness of the string. I like to make my grooves with a three-cornered file so that the string rests only on each side in the bottom of the groove. The nut needs to be of hard material. I like dense bone on my acoustics and marine brass on my electrics. The object is to reduce friction at the nut. A little bit of graphite lubricant or even Teflon under the string will sometimes help. Observe that on guitars with in line tuning machines (all on one side), the string theoretically travels straight to the tuning peg whereas in a traditional three-on-each-side layout, the string not only angles downward but also sideways a bit. In my opinion, the groove should pick up the angle straight to the tuning peg right from the edge where the string leaves the fingerboard. Other builders like to let the string take a gentle curve over the top of the nut. An argument can be made for both techniques. The important thing is that the string (so far as its vibration is concerned) must see the nut as a dead-end, a brick wall. If it can vibrate or move back and forth in the nut, it will cause buzzes and rattles and other difficulties.

4. In my opinion, the hold-down Tees are an inadequate solution to a basic engineering problem. The necks were designed straight for ease and economy in production. A headstock that lays back at 15 degrees provides the necessary break angle over the nut with out hold-downs. You have two choices. Don't go under the Tees with the string at all (which may cause rattles and sustain/harmonic issues) or very carefully smooth and polish the bearing surface under the Tees and just put up with them. Here again, lubrication will help somewhat.

5. Moving on down to the bridge, on an acoustic flat-top, the string peg holes must be correctly sized and not worn out. The top of the saddle should be gently rounded and enough bearing surface for two or three windings of the string to bear on. The windings will tend to make little dimples where they want to sit. That's not usually a problem because there is only a very short bit of string beyond the bridge and it breaks at a steep angle down into the peg hole. When you stick the ball end of the string into the hole and then guide it into the groove of the peg, be sure that the string comes up and wedges against the peg securely. If the string can move or give in the peg hole, it will surely cause tuning problems. If there is work to be done here, it almost certainly needs to be done by a qualified technician with the right tools and knowledge.

6. On other types of guitars, there may be six inches of string beyond the bridge. If there is any way for it to bind, it can cause tuning issues. Carefully smooth and polish the individual saddles, or grooves if there are such, so that the string can distribute tension equally. The Gibson EB1 bridges with the individual saddle pieces are a bit troublesome in this respect, especially on a guitar with a trapeze tailpiece. Those tailpiece units are not very stable and, like a vibrato tailpiece, anything that one string does (like bind up and then give a tiny bit) will affect each of the other strings.

7. A final few words about tuning problems with vibrato bridges. A design wherein the bridge and saddles all move together is the best. Typical Strats and Floyd Rose designs work best. The Bigsby type where the strings go over the bridge and then to the vibrato tailpiece cause the most difficulty. The trick is to free the bridge up so that it can move with the strings rather than forcing the strings to tighten and loosen over the bridge. One way to do this is to drill out the holes on each end of the bridge to accept a short piece of surgical rubber tubing over the stud screws that anchor the bridge. The resilient rubber will return the bridge to its correct position and yet still let the bridge move with the strings during vibrato action. The best setup in my opinion for a solid body guitar using light gauge strings and needing a vibrato bar is a quality locking nut where the strings can be immobilized after initial tuning, and a Floyd Rose style floating bridge with individual string tuners built into it. It will tune up accurately and it will stay in tune until something actually disrupts the tension balance-like breaking a string. Guitars set up this way are difficult and time consuming to restring, and they are a mechanical nightmare to take apart and reassemble.

Tips & Warnings

• A note on staying in tune while you are playing a guitar with a vibrato tailpiece. Recognize that bending an individual string will affect the tension in the OTHER five strings. When you release the bend, the guitar will probably not come back perfectly in tune. A quick tap on the bar will usually free everything and balance the strings again.

• A note on tuning your guitar. Always bring the string up to pitch rather than ever going too far and trying to release tension down to pitch. This will keep any accumulated uneven tension on the same end of the strings and will tend to make your tuning more consistent.

• A note concerning string gauge. The lighter gauge (read "lower tension") strings you use, the more difficult it will be to get the friction at the various binding points low enough so that the string will transmit its tension under the Tees, over the nut, and over the bridge so that the whole string is at the same tension.

• A note concerning how you string up your guitar. When you first put a string on and tighten it to pitch, it will tend to make a little kink where it goes over the bridge and over the nut. The string will then try to return to that position even when you are in a different environment where it is warmer or colder and the string is actually a tiny bit longer or shorter due to thermal expansion or contraction. It's a small effect, but its there.

• Another note concerning how you string up your guitar. When you wind the strings onto the tuning pegs, be sure to get at least three wraps. Make sure the string has a right angle bend to hold it in place against the hole in the peg or in the slot as you tighten it. Use some good way of securing the string-granny knots are not acceptable. Wind the string smoothly onto the peg and toward the bottom so that it puts adequate downward pressure on the nut.

• A word of warning here-if you attempt to cut and groove your own guitar nut, exercise great care. In fact, don't do it at all until you are sure you understand how to obtain the correct string clearance over the first fret. That in turn is dependent on the height of the action, which is a function of playing style, neck relief, and bridge height.