I take calls in the shop all the time from customers asking to bring in guitars for inspection convinced that their necks are warped. To the owner's great relief the vast majority of these warped necks are only poorly adjusted and a proper set-up puts things right. The subject of warped, twisted, bowed, and bent guitar necks is based in fact and surrounded by fiction.

Some fiction: First and foremost is the notion that a neck will warp if you remove all the strings from the guitar. It simply doesn't happen. You can do this without damage to the neck. In fact that is one of the first things we do to your guitar when we do a set-up. With the strings off, the electronics cavity of a Strat is easily accessible for cleanings. The neck, body and bridge parts of any guitar are easier to clean and check with the strings off the guitar. Nothing adverse will happen to the neck unless you don't plan to restring it for months. I think the tale may come from the fact that with the strings off the guitar, the neck will flex back somewhat. Remember, the truss rod was adjusted to counter the string tension. With string tension gone, the truss rod will bow the neck slightly but the effect is temporarily. Guitars are designed for this tension. They are meant to be flexible.

Second is the notion that guitar necks are supposed to be straight. This is also false. Although we do use the word "straight" to describe a good lookin' neck, a properly adjusted neck is actually slightly bowed or flexed in the direction of the string tension, with the fretboard slightly concave from end to end. A neck that is set dead flat level will not play without buzzing on it's frets. This slight bow is called "relief". Imagine a string stretched between the two points of nut and saddle.

At rest, the string is straight and level relative to these points. Pluck the string and set it into motion. It's vibrating pattern is in the shape of an elipse -- narrow at each end, reaching it's widest pattern at the middle of it's length which corresponds to the area of the 12th fret.

The relief bow gives the string the room it needs to vibrate without interference. Sight down the edge of a guitar neck, looking from the nut toward the bridge. Try to follow the lines of the tips of the fret. You may be able to see the relief bow. It will be even and gradual from the nut to about the 4th fret. Then it may appear to level out from about the 5th fret to the area of the 14th fret and then drop off at the very end. Don't be concerned if you don't see it; it requires experience to know what to look for. However, if your guitar is playing well, the relief bow is there. So, I guess it's fair to say that guitar necks are straight. But, straight like a guitar neck, not straight like a ruler.

Some Facts Guitar necks all develop warps, twists. and bows that require anything from minor truss rod adjustment to major heat and reshaping to reverse. The most severe of these problems I'd call natural warping or twisting. Natural warps are caused by the forces on the wood acting on the wood itself. Because wood is a natural product it can be unpredictable. No two pieces of wood react in exactly the same manner. Even two pieces cut from the same tree can respond differently to seasonal humidity changes. Wood that is to be used for musical instrument making is selected, cut, and dried, specifically for that purpose. Music wood is cut differently from wood that is to be used for furniture making or general construction. Music wood is dried for 12 years or more. It is cut or split from the log so that tile grain is as straight as possible from bottom to top, end to end. This is called quarter cutting. Even with the best of precautions, however, it's not always possible to predict how a piece of wood will act and react over time. Poorly cut or chosen neck blanks can warp and twist unpredictably. Very exotic woods with fancy flames or heavy birds eye patterns are candidates for warping because of their uneven grain. Though I'll admit a Birdseye maple neck is gorgeous, it may not be stable enough. The plainer and straighter the grain, the more stable the wood.

Natural warps are the strongest and though they do sometimes respond to repair methods, results are usually temporary. So if your beloved guitar is subject to this type of warp or twist you may chose to have the neck straightened and re-straightened from time to time. It may actually be worth it to have it regularly repaired and accept it as the cost of owning all otherwise fine instrument. Or simply, have the neck or guitar replaced. This type of unrepairable warping is most often covered as defective under the warranties of the better manufacturers. This option is, of course, subject to the terms of each individual manufacturer's warranty, but from my experiences in the shop, it pays to buy brand name instruments with reliable service packages.

More common are the warps twists, and bows that are the result of putting strings on a guitar, tuning it to pitch and playing it -- normal use and abuse. An improperly adjusted truss rod, tops the list of use and abuse normal warp causes. Modern guitars are designed to be adjusted to the player's likes and style. That's what a setup is. After all, the same Les Paul or Strat can be properly adjusted for anything from .008's to .013's. But a guitar that has been setup for .009's and is strung with .011's will develop a forward bow. The string tension will be stronger than the truss rod tension. A guitar setup for .011's and strung with .009's will develop a back bow. The truss rod tension will force the neck back stronger than the strings can pull it forward. The goal is a balance between the two. If left untreated, these necks will need repair.

A neck may also reach a point at which it's trussrod is no longer effective. Adjustments over a long period of time have left the rod working but at the end of it's threads. In either direction it just ran out of room. Because these bows were forced into the wood from either string or trussrod tension they can be reversed. Heat pressing is in order. Customers sometimes ask about having the neck "steamed". Steam is not used for straightening necks. Steam is too wet for this purpose. Steam is only used to remove a neck from a glued dove tail or mortise and tension joint. The moisture and heat are ideal for softening the glue allowing for clean removal.

Heat pressing is done with a dry heat source. We use a heavy clamping bar that contains heating elements The bar is long enough and rigid enough to allow the neck to be straightened using clamping pressure and spacer shims. Once the neck is reshaped on the clamp bat the heating element is turned on and left on long enough to heat the neck through. The element is gauged to reach a maximum tempt of about 140 o F. This is just hot enough to both change the shape of the wood fiber and also soften the glue joint between the neck and fretboard though not so hot as to damage the finish or binding. The wood fibers will cool to the shape placed in the neck by the clamps. The softened glue joint allows for minor shifting of the two parts. Once completely cooled the truss rod is again used to adjust the neck for it's needed tension. More than one session on the bar may be necessary to shape some complex bows or twists. When properly done. the procedure is quite effective. Heat can cause the warping so be aware. Don't store or leave the guitar near or in hot environments. The most obvious heat sources are radiators and heat vents During the summer avoid storing guitars in attics or rooms subject to regular high temperatures. Remember that a black guitar case in the summer sun is a solar oven. The same for the trunk of a car. The heat generated in the trunk of a car on a hot summer day can soften glue joints, melt finish, and reshape wood. Damp cellars can cause similar damage A good general rule is: If you're comfortable, your guitar is comfortable. Avoid extremes of temperature or humidity and have your guitar set-up regularly -- small problems left unattended can become expensive.