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Fundamentally, two types of guitar neck construction exist; single and two-piece. In a single-piece neck the headstock is cut into the same piece of timber as that of the rest of the neck. In a two-piece neck, a separate headstock part is joined onto the longer part comprising the greater length of the neck using a scarfed joint. Origins Of The Term The term "scarfed joint" reaches back to traditional timber building and ship construction to denote a type of joint used to produce a long piece of timber where one single piece would not otherwise be possible. The joints themselves were often complex and varied, not glued and instead used a combination of friction, mechanical locking using wedges/pins, fasteners, gravity, etc. The development of strong adhesives beyond simple protein glues changed joinery and produced a whole new book to describe them. The term "scarfed joint" was appropriated and used to denote both the a lengthening strategy for joints glued at an acute angle for increasing mating surface area for glueing and as a method for improving the cosmetics of joints that would otherwise require weak and aesthetically poor butt joints, such as veneer wrapped around a cylinder. The term has again evolved in usage to describe how a two-piece neck is constructed for a guitar, derived solely from the increased mating surface areas they produce for glueing. In some ways it has become simplified over its original base meaning. So much so, the more descriptive and correct term "scarfed joint" has devolved into "scarf joint". Both are correct in the context of guitar neck construction through adoption (language and meaning evolves) however we'll stick to the more specific term "scarfed" for this article....we'll see why this is meaningful later.... Headstock Angles Most people will be familiar with the difference in headstock angle of a Gibson Les Paul versus that of a Fender Stratocaster. Whilst Fender-style designs have a headstock that lays in the same flat plane as the rest of the neck (zero headstock angle), headstocks of Les Paul-style headstocks typically fall away at an angle anything from a few degrees up to 20°. A few terms exist such as "angled headstock", "tiltback headstock" however they all represent the exact same thing; that the plane of the headstock is at an angle with respect to the rest of the neck. Angled headstocks offer benefits over flat headstocks, such as greater string pressure over the nut and the elimination of string trees. A side benefit is that they can also allow for easier access to the truss rod for adjustment. Why Use A Scarfed Joint? The main two reasons that scarfed joints are used is for the strength that they add to the finished workpiece and also one of economy. Many builders also incorporate aesthetic values to their scarfed joints as a secondary aspect, which in many ways also distracts from the true purpose of the joint being there in the first place. Wood Strengths/Weaknesses Wood is not an isotropic material; it is weaker parallel to the grain direction and splits along this easily. For necks whose length is more or less in line with the grain, (flat zero angle necks or very shallow angles) this is rarely a problem. The grain travels uninterrupted along the entire length from one end to the other. Headstocks angled against the direction of the grain build in an inherent weakness called short grain. This is simply the path of least resistance through the grain into and out of the wood, in this instance from the rear of the headstock a short distance through to the front. The greater the angle of the headstock, the shorter the grain distance and the weaker the headstock. Areas of short grain (red) in a single-piece angled headstock against normal grain direction (green) Short grain is one of the main reasons that Gibson guitars and basses are so prone to headstock breakage. Decades of adherence to their traditional building style maintains this weakness in spite of a simple solution having been around for far longer. The scarfed headstock joint. By glueing a second angled piece of wood to the first to produce a scarfed joint, short grain is virtually eliminated Economy It should be fairly apparent that a headstock angled against the plane of the timber increases the minimum dimensions that the timber is required to have for a single-piece neck, increasing the waste factor. Several strategies are possible for turning this into a more economical venture by employing a simple scarfed joint. The following diagram shows how shorter material can be used economically by recovering material wastage underneath the neck and using it as a scarfed headstock: Volutes In guitar terminology, a volute often refers to a strengthened area behind the union of the neck shaft and the headstock. These are useful for a number of reasons, not all of them related to scarfed joints. In this context however, they can be useful to lengthen grain when scarfing on a thicker headstock component that would otherwise invite short grain under the first two frets. Volutes also offer cosmetic options for hiding the join line; same as how a headplate can be added to the top of the headstock, a bent "backstrap" can be added to the rear face. A thicker scarfed headstock can add short grain from under the headstock The addition of a volute lengthens the area of short grain, adding vital strength Types Of Scarfed Joint As touched on earlier, the term "scarf joint" is less meaningful than "scarfed" since we're really discussing the idea of two-piece construction over single piece rather than any specific type of joint. There's no language police here, and both terms are just as correct through widespread usage and basic adoption. It is however useful to consider that there's lots of ways to achieve this end. The most common type of scarfed joint is that shown above; an acute face milled into the end of the neck, and a second flat piece of wood glued on. Several common methods exist to create a scarfed joint, however they all have two common aspects; they increase the mating surface areas of the two parts to ensure a strong glue bond whilst eliminating as much short grain as possible. The two most common types of scarfed neck joint; over and under the neck Notable exceptions to the common approaches on scarfing a headstock joint are the V-joint employed by Martin and many classical guitar makers, however this is seldom found on electric guitars or steel-strung acoustics. Cosmetically, this style of joint can be accentuated into a "dart" or even a diamond-shaped volute. Making a V-joint - https://www.youtube.com/watch?v=KocJHchKVZQ ....or the far more weird finger joint as employed by industrious inventor Bob Taylor: It might look strange, however as well-engineered as joints go this is near perfect in all but cosmetics In Closing Scarfed joints are an important building technique to increase the reliability and durability of guitar necks with angled headstocks, plus afford us opportunity to use raw materials more responsibly. However the joinery is approached, a well-planned and executed scarfed headstock produce an end product that can be both beautiful and superior to those made from a single piece of timber. They simply need to be applied to the problems that they are intended to be solving. Over in the tutorials section, we'll look at the different techniques used to produce basic scarfed joints plus jigs to simplify the various processes....

The steps in this tutorial are meant to be followed in the order they are presented, failure to do so can cause frustration, a waste of time and a poor setup. If you are confident that you can skip a section by all means do so to save yourself some time. In many of these tutorials measurements are used as a guideline and not a solid fact, you may need to change or adjust these measurements for your own personal playing comfort. For this particular tutorial there are many pictures of different types of guitars in each step to help you better understand your own. Step 1 Headstock Area First start out by making sure all of the screws holding your tuners on the head stock are tightened down correctly. For your reference I have photographed most of the common styles of tuners found on modern day solidbody electric guitars and under each one you will see a description and also a pointer in the picture where the screw is located. Common sealed tuners - 1 screw per tuner In-line open tuning machines - 7 screws per strip Kluson Deluxe tuning machines - 7 screws per group Generic closed box tuners - 2 screws per tuner Sperzel locking tuners - no tie down screws Generic sealed tuners - no tie down screws Try not to over tighten these screws as the threads will strip out the wood easily. If you should run across a screw that is in this condition pull it out completely and dab a little wood glue on the end. Insert it back into it's original hole and wipe off any excess; this will help the screw retain itself. Alternatively, insert a matchstick into the hole with a drop of thin cyanoacrylate (CA, crazy glue) or wood glue. Once dry, carefully redrill a pilot hole for the screw and replace. If the screw itself needs replacing (stripped head, etc) you can generally order one through your local music store or hardware outlet. The most common size is a 7/16" #2 Phillips head. Now move on up to the top of your tuners and make sure the individual buttons are screwed down tightly. Believe me it is an embarrassment if you go to tune up and suddenly you're lost because the button keeps spinning and the spindle goes nowhere leaving you tuned exactly where you were to begin with. Or even worse yet it falls off leaving you searching the ground like somebody dropped a contact lens....these screws are machined small and it can be difficult to get a replacement. The turning action of many tuners are loosened or stiffened by adjustment of the button retention screws. "Finger tight" is preferable to locking them with force or flapping in the wind. Now make sure the front of the tuner is firmly mounted. For press-fit bushings (left) they simply need to "not be loose". If a push-fit bushing does become loose, the tiniest amount of yellow/white wood glue adds sufficient (but non-permanent) retention in the wood. Tuners with screw-down ferrules require either a socket wrench or a spanner for tightening. Tuner bodies and ferrules are often made with softer metals, so torquing these down tight is not advisable since it is easy to break components or strip out the threads. Just beyond finger tight is sufficient. If your guitar is strung up loosen each string individually and check for spindle movement by grabbing the top and wiggling it. It is fine to have a small amount of play but generally little to no play is the accepted rule. If you have open back tuners you can adjust this by tightening the screw located on the back of the gear as pictured below. Otherwise, if you are experiencing too much movement you should consider replacing your tuners. Tune your string back up to pitch and move on to the next tuner. The last thing to check on the headstock are the string trees to make sure they are snugly fastened down. Not all guitars have these and there is a wide variety available on today's market. Below you will see pictures of the most common ones. Standard 2 string tree Full neck string tree 2 string roller tree Step 1: Introduction and headstock area Step 2: Trussrod and neck bow adjustment Step 3: Nut height check and adjustment Step 4: String height and bridge adjustment Step 5: Adjusting the intonation of a guitar Step 6: Adjusting pickup height