Everything You Ever Wanted to Know About Maintaining a Guitar (But Were Afraid to Ask)

Guitar maintenance can be a frustrating and expensive business. This instructable aims to help with that. If I missed something you think should be included, let me know; likewise, if you've got a question, put it in the comments and we'll see if we can't get you squared away.

Step 1: Know Your Instrument

An overview of the different parts of the guitar, so, just in case you don't know the official term for something, you won't miss what I'm trying to say. See the diagram for the most basic parts.

Nut: found at the headstock end of the neck, sets the start of the strings' fretting span
Bridge: found on the body at the other end of the strings' fretting span
- Saddle: the parts of the bridge over which the string "breaks"
- Hardtail bridge: a 1-piece stationary bridge that sits low to the body, with saddles that can be individually adjusted for height and distance from nut; the ball end of the strings may attach directly to it, or be passed through the bottom part of it, through the body, and sit in a ferrule on the back of the body
- Tremolo bridge: a 1-piece bridge with an arm that, when pushed/pulled, tightens or loosens the strings, causing the pitch to go up or down; depending on the specific type, the ball end of the stings may pass through a channel in the base plate of the bridge and through the body, or be clamped down behind the saddle
- Tune-o-matic bridge: a stationary bridge that sits high from the body, with saddles that can be individually adjusted only for distance from nut; must be used with either a tailpiece or through-body string channels and string ferrules
- Tailpiece: used with a tune-o-matic style bridge, holds the ball-end of the string; can be stationary or tremolo (Bigsby-style tailpiece)
String break: the points at which the string stops vibrating when struck; there is a string break at the nut and at the bridge
Action: the distance between a string and the fingerboard
Relief: the vertical curve of the neck
Scale length: the distance between the nut and the bridge; determines the distance between frets required to pitch the notes correctly
Pot: potentiometer; responsible for adjusting volume and tone; basically, what your knobs are attached to
Cap: capacitor; used on tone pots to reduce the amount of treble signal reaching the amp
F-hole: decorative hole cut in the top of a hollowbody or semi-hollowbody guitar; usually in the shape of a stylized F, but called an f-hole (or f-holes) regardless of the shape
Binding: decorative plastic strip around the edges of the body, neck, and/or f-holes
Horn: the part of the body that extends up along the neck; singlecut guitars (such as Les Pauls) have only 1 horn, on the knobs side of the body

Step 2: Changing Strings

If you play regularly, you'll need to replace your strings more frequently, but even if you don't, change them every 4-6 weeks to keep your guitar sounding its best. You can tell when strings need changing by how they sound and look. Old strings sound lifeless, and will be discolored over the frets.

What You Need:

Wire cutters
Guitar tuner
New strings

How to Do It:

Loosen the old strings by detuning them
Use the wire cutters to clip the strings in the middle
Remove the old strings from the bridge and tuners
If you're going to clean and polish the guitar, do it now
- Use a polish made for guitars so you don't ruin your finish
- If you have an unfinished fingerboard (rosewood, ebony), every couple of months put a few drops of lemon or olive oil (actual oil, not furniture polish) on a rag and rub down the fingerboard wood
Take a standard #2 pencil and rub the tip over the saddle and nut slots to lubricate the string break points; if your guitar has string retainers, do the same on the underside of the retainer, as well
Install the new strings, 1 at a time:
1. Push the string through the tailpiece or string channel and over the appropriate saddle
2. Insert the string through the appropriate tuning peg, and pull it relatively tight; if you're using locking tuners, pull it as tight as you can, otherwise, leave a little bit of slack
  
  Note: Even with locking tuners, you're going to get a bit of slippage, especially on the thinner strings; I've found I need to leave a little extra on string 1, enough to wrap a couple times, to prevent the string slipping out altogether (your mileage may vary, depending on the tuners you have).
3. Tighten the string by turning the tuning peg key; the direction depends on which side of the headstock the tuner is installed on--if on the left side, turn it away from the bridge, and on the right, towards the bridge (you want the string to be as straight a line as possible from nut slot to tuner)
4. On non-locking tuners, bend the extra bit of string so it points straight up after emerging from the tuning peg; as you wind, you want the loops to trap this part of the string in place; see the diagram for specifics
5. Tune it to the proper pitch; especially on the thinner strings, be careful not to over-tighten and break the string
Tune each string to the proper pitch
- Thickest string is 6, thinnest is 1
- From 6 to 1, standard tuning for each string should be E, A, D, G, B, E
As you install each string and tune it, go back to the previously installed ones and retune them
Once all of the new strings are on, stretch each by pulling it up and over, towards the middle of the fingerboard, at various points along the string--again, be careful not to break it; do this, then retune, then repeat until each string stays in tune
Use the wire cutters to clip the excess string

Step 3: Set the Relief

Before setting the string height, set the relief--the curve--of the neck. You can check this by placing the guitar on its side and looking down the neck. Use the string as a straight edge; this is easier to do on the low E side. Most people like a very slight forward bow to the neck (that is, the strings are slightly closer to the fingerboard towards the nut than they are towards the bridge); you can also have it perfectly straight--completely up to you. What you don't want is a back bow, because you're going to get buzz halfway down the neck.

Relief is set by adjusting the truss rod in the neck. Depending on the guitar, you may do this at the headstock or at the base of the neck. On some Fender-style guitars you may need to remove the pickguard to get at the adjustment screw. Remember the lesson long passed down to us by our ancestors: righty-tighty, lefty-loosey. Tightening the truss rod will increase forward bow, and loosening it will increase back bow.

It is extremely important that you don't get carried away with this. The most you're ever going to tighten the truss rod's adjustment nut is a quarter turn. If that much adjustment doesn't fix it, take it to a repair shop. Over-tightening it can strip the truss rod, pop the fingerboard off, even warp or snap the neck.

What You Need:

Screwdriver with the appropriate tip for your truss rod; most are either phillips or hex
A straight-edge, like a metal yardstick

How to Do It:

Loosen the strings slightly
Prop the guitar on its side
Hold the straight edge against the frets, or press the string down on the first and last frets to create a straight line
Loosen or tighten the adjustment nut until the straight edge is completely flat against every fret
Retune the strings; this will naturally add a small amount of forward bow; this is the desired amount relief
This is also a good time to check for high frets: place a short straight-edge (like a 6" metal ruler or similar) on a fret and try to see-saw it back and forth; it shouldn't move, but if it does you've got a fret that may need to be re-hammered in a bit or re-dressed

You shouldn't need to adjust the relief regularly, but it's a good idea to check it if you change string gauges or if the guitar gets exposed to extreme temperatures, hot or cold.

Step 4: Set the Action

Action is mostly a matter of personal preference. If you play mostly lead, and want to be able to play fast, you want it as low as it can go; if you do a lot of open string drones or chords and don't want to accidentally fret notes, you'll want it somewhere in the middle; if you're playing slide, you need it very high. If you do a lot of bending, you don't want the action as low as possible, as the string will "fret out," which is when the string hits a fret and stops ringing.

On tune-o-matic style bridges, you're going to raise or lower either side of the bridge, with no option to individually adjust the saddles. On Fender-style bridges, each saddle can be raised and lowered independently. Generally speaking, you want the arch of the saddles to match that of the fingerboard. (The exception to this is for playing slide, where there usually is no arc to the strings at all.)

To lower the saddle/bridge, tighten the set screw(s), and loosen them to raise it. This will change the pitch of the string, so retune it before you check how it plays. Regardless of your preference for the height, you want no buzzing when you fret a note, anywhere on the neck. If you get buzz, you need to raise it a bit.

Step 5: Set the Intonation

In most basic terms, setting the intonation is making the guitar play at the exact same pitch when the string is struck unfretted and when fretted at the 12th fret (the octave). More technically, it's making sure the distance from nut to saddle is exactly correct for each string, so that the exact correct note plays when fretted.

You'll need to do this when a guitar is new, because they don't set it at the factory, and if you change string weights. If you've been using 10s and switch to 11s, gotta reset the intonation. Before starting, make sure your action is set where you like it. And make sure you press down like you normally do when playing the fretted note; too hard or too light will cause the note to ring incorrectly.

What You Need:

Guitar tuner
Screwdriver

How to Do It:

Plug the tuner in to the guitar
Tune the open 6th string to pitch
Fret the note at the 12th fret and strum the string to see if it needs to be adjusted, and in which direction
If the fretted note is sharp, tighten the saddle screw to move it away from the nut; if it's flat, loosen the saddle screw to move it toward the nut
Tune the open string to pitch again
Repeat these steps until the open note and fretted note are both perfectly in tune
Repeat these steps for each of the other strings

Step 6: Pickup Tweaks

String Height
Before you spend a ton of cash on new pickups, try changing the height first. It's a stupid-easy solution that can have a drastic effect on tone. If pickups are too close to the strings, you can get a lot of microphonic noise (string rubbing, pick clicking, etc), and it can also have a weird effect on the tone. If they're too far, the sound will be quiet and muted, like you're playing through a blanket. My personal sweet spot for height is for the pickup poles to be about 3/8" below the string when fretted at 15. There's not really a wrong or right with where you set them, exactly, beyond not too close or too far.

Changing Pickups

A pickup change is almost certainly the most common upgrade guitars get. Almost every guitar I've ever owned eventually got one, whether because the cheap pickups that come on budget guitars often break or sound like garbage, or because you just want to change the sound of the guitar.

Do your research before buying--pickups can be extremely expensive, but solid ones can be found without having to pay an arm and leg. Check YouTube for demos, read the manufacturer descriptions, read reviews; and think about what kind of sound you want. If you're playing metal, you don't want a jazz pickup or humbucker-sized P-90; if you're playing jazz, you don't want a way-overwound metal pickup that never even thought about a clean tone.

Make sure you get the pickup you need, as well. Pickup cavities, mounting rings, etc. are (mostly) not created equal. Check the pictures to see which you have. There are 2 exceptions to this: single-coil pickups (Strat style, lipstick style, Mustang/Jaguar style) are mostly interchangeable. And the body cavity for p-90s and mini-humbuckers is the same, though you'll need a mounting ring or to drill mounting holes in the pickguard if going from p-90 to mini-humbucker.

For p-90 and Telecaster pickups specifically, you also need to get the right form factor. P-90s come in soapbar, which are screwed directly to the body and sit in a cavity, and dog-ear, which mount similar to most other types of pickup, hanging on a screw to either side. They are not interchangeable. Standard Telecaster bridge pickups have a different baseplate than other single-coil pickup styles, with 3 mounting screws instead of 2. And Telecaster Deluxes, and some Thinlines, have wide-range humbuckers, which are bigger than normal humbuckers.

Also, pickups are made specifically for neck or bridge; while you can install a bridge pickup in the neck position, or vice versa, it's not recommended. Bridge pickups are typically louder than the neck version of the exact same pickup model, to compensate for (usually) being further from the string, and the difference in the way the string rings just before the bridge (because it's the end of the line, the vibration loop has a smaller diameter than further from the edges--think about 2 girls holding either end of a jump rope and swinging it).

Pickup Installation
If you're doing a straight swap, not changing out anything else with the other electronics, and know how to use a soldering iron, this is really easy. Unscrew the original pickups. 1 at a time, trace the pickup cable to the pot or switch lug, and unsolder the hot lead(s) and ground, and remove the pickup. Install the new pickup, and solder its hot lead(s) and ground to the same locations as the original. This instructable has complete instructions on the process.

Step 7: Random Upgrades

Switching Out Knobs
Don't like your knobs? Change them! But don't just yank on them, you're likely to bend the pot shaft. Take a piece of cloth--hand towel, washcloth, t-shirt--and wrap it around and under the knob, then pull up on the whole thing. This distributes the pressure evenly around the base of the knob, so it should pop right off. Then press the new one down. One thing to be aware of, some older guitars--you almost never see these anymore--will have pots that require a set-screw knob. It's easy to spot one--on 1 side of the knob there'll be a small, usually flat head, screw that tightens down to keep the knob in place. While you won't have as much selection when looking for new ones, they can be found.

Graphite Saddles
Graphite saddles are a good upgrade, especially for tremolo users. They reduce breakage and tuning problems, and will (somewhat) increase string life. You can find them online for pretty reasonable prices (I paid $32 for the most recent set I bought). Switching them out is incredibly easy: take the strings off, unscrew the saddle nuts all the way, pop the original saddles off, put the new ones in, and re-screw the saddle screws. You'll need to set the action and intonation again.

Changing Nuts
With the exception of more high end guitars--PRSs, $1500ish+ Gibsons, etc.--most guitars are going to come with a plastic nut. It's not the worst thing in the world, but a swap can improve tone, sustain, reduce breakage and tuning problems. There are quite a few options here: graphite, bone, brass, TUSQ. Each has it's own advantages and fans, so it's really just a matter of what you're looking for.

Graphite/TUSQ: the main advantage is lubrication, which increases string life and helps the guitar stay in-tune, especially helpful if using a tremolo. This is probably the best choice if you don't want to make one, as they can be purchased pre-cut and slotted for most standard neck widths.
Bone: the classic nut material, the main advantage is tone; however, you're going to have to make it yourself, or pay a luthier/repair shop to do it
Brass: tone is better, and most people say you'll get more sustain; like with bone, you're probably not going to be able to find a pre-made one

To change a nut, take the strings off (you can just loosen them enough to pull out of the nut slots, don't need to completely remove), pop the original nut off (you may need to apply some heat or pressure, if it's been glued on), put the new nut in its place, and put the strings back in place to check fit/alignment. Once satisfied with it, take the new nut off, put a drop of superglue on the bottom of it, and put it back in place.

Tremolo Blocking
If you're not using the tremolo on a Strat-style guitar, every string going out of tune at the same time, or because 1 string broke, has no doubt annoyed you. This is probably the easiest fix on this list. All you need to do is find something to insert into the tremolo cavity on the back of the guitar to keep the bridge block from moving. This could be an actual device built for this purpose, like the Tremol-No, or just...anything. A piece of wood, a taped-up stack of old Chuckie Cheese tokens (I have done this one), literally anything that will fit.

Change Electronics
Cheap pots and switches will make even expensive guitars sound worse than they should, adding unwanted noise, uneven volume/tone ramping, buzz, etc. Get good quality pots and switches, and switch 'em out. Switchcraft switches are generally accepted as the best available, and CTS pots likewise. Same procedure here as with the pickup switch: unsolder the original pot, remove it, install the new one, solder the wires back to the same locations.

Changing out the capacitor on your tone pot can also help. The capacitor controls how much treble is removed from the signal as the pot is turned down; different values will make this change more or less drastic, so you can have just enough to take the edge off all the way to simulating a wah pedal with your tone knob. This article has a rundown and audio samples of different capacitor values' effects on tone.