Cape Cod Acoustics
  • Home
  • Your Lessons
  • Performance services offered
  • About Gene
  • Contact
  • Guitars, Ukes & Accessories
  • Acoustic Guitar Blog
  • Tips for guitarists
  • Guitar Gallery
  • More...

Part 2: Guitar Necks: what you need to know

12/8/2010

0 Comments

 
Strings on a steel string acoustic guitar put a tremendous amount of stress on the instrument and wood being a natural material, that stress has to be handled with attention to the fact that wood is basically unstable. The challenge that makers face is simple and at the same time tremendously complex: how to allow the vibration of the string to be transmitted using the lightest materials and bracing possible and at the same time maintain structural integrity. Not an easy thing, for sure!

The three parts of a guitar that carry the stress most are the neck, front and bridge. Guitar makers have settled on a few types of wood for those parts based on literally centuries of trial and error. The neck may be the most important.


Picture
This is the back of the neck of my Martin 0000-28H. The neck is made of mahogany (that small diamond shaped section near the top is called a volute - it gives the neck a bit more strength at the point where the angle of the wood changes). Mahogany is by far the most popular wood used for necks because of its nice straight grain and resistance to warping or twisting. Some makers use laminated sections of wood, which may be even stronger than a single piece of mahogany.

In the last few years good quality mahogany has become harder to find for the makers and because of the flattened shape of the top where the tuners are installed and that slight angle so the strings will press firmly on the nut, a much larger piece of mahogany is required than one would think looking at the long, narrow shape of a guitar neck. This has forced makers to make compromises. Martin makes some guitars with what players refer to as "wings" : small pieces of flat mahogany bonded to each side of the head. I've heard that this small alteration saves something like 25% of the wood needed to make a single piece neck. Although it is generally recognized that the use of wings has no affect on the sound or the strength of the guitar, some players object to the look of them - although Martin goes to great lengths to stain the wood and match the grain so that the wings are not obvious. Wings are a big subject of discussion on the guitar forums such as the Unofficial Martin Guitar Forum and and The Acoustic Guitar Forum and to my mind, the jury is still out on that subject. I do know that Martins with wings are often less desirable on the used guitar market. Time will tell whether that will always be the case.

Taylor Guitars often gets around this by using a "finger joint" at the point where the angle changes between the head and fingerboard. Personally, I don't like the way that looks at all and it might even be a deal breaker for me if I was considering buying a Taylor. Not all Taylors have the finger joint however; some are a single piece, some have a tapered oval shaped joint. I have read about both types of joints failing on a few Taylors but the company must feel this is not a big problem because they continue to use those solutions to wood shortage.

Some companies have begun using a man made composite for the necks of some of their less expensive guitars, including Martin with their new and very popular 1-series instruments. They also use it in their popular travel guitars. They call the stuff HPL and while it is quite different in appearance and some have complained about the weight of necks made with the stuff it is apparently all but impervious to changes in humidity and is much stronger than mahogany. Does it affect the sound? Most say no. This may very well be the future of less expensive acoustic guitars.

Speaking of the affects of temperature and humidity, although mahogany is extremely strong and quite durable, it can be prone to changes as the seasons progress. This is somewhat annoying but should not be a huge cause of alarm if your "plays like butter" guitar suddenly has strings that are much higher off the fingerboard, or worse, buzzes begin to appear as you play because the action is too low. In most cases these things can be dealt with by turning the inset screw mechanism that will be found either just under the upper bout inside the body or under a plastic plate up on the head. What happens is a long rod that is installed between the fingerboard and the neck will slightly change the angle of the neck- this is called the "relief." A big, big word of caution here. Keeping in mind that turning in a clockwise direction will result in less relief (lower the action) and turning counter clockwise will do the opposite, ALWAYS  loosen the strings, look down the neck to get an idea of the relief before adjustment, then make about a quarter to a half turn, tighten up the strings and check the effect. If it isn't what you want, go through the process again. Resist the temptation to give it a few cranks right off the bat because it is highly unlikely you'll accomplish what you set out to do and you could potentially do severe or even fatal damage to the neck. If you have any trepidation about the process, bring your guitar to an accomplished repair person.


Sometimes though a more serious neck issue can develop. If a neck "goes out of set," the action will get higher and higher until it is virtually unplayable, the result of that steel rod not giving the degree of support it should and the wood reacting to the stress of the strings. You can make a basic determination if this is happening by looking down the neck. If you see an abrupt change of angle at some point, rather than a curve, it could very well mean a net reset is called for. This is a big decision because a neck reset is essentially open heart surgery for a guitar - the neck will have to be removed, the rod reset and the heel may have to be sanded or shaved to get the right angle again and low action. Luthiers can charge anywhere from a couple hundred to $400 or more for this job depending on the complexity. You then have to decide whether your guitar is worth that investment. For what its worth, guitars with a mortise and tenon neck are less expensive to reset than ones with a dovetail joint. This is because M&T neck attachments usually are nothing more than a large bolt that is hiding under a plate of wood inside the guitar. It's worth considering this job carefully - before I even knew what a neck reset was, many years ago, I traded my first Martin, a D-35, for a ...... gulp...... Yamaha because I thought my D-35 had a warped neck! Live and learn.

Next time we'll look at fingerboards and bridges.

Peace & good music,
Gene

0 Comments



Leave a Reply.

    Author

    Gene Bourque

    Archives

    June 2022
    May 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    July 2021
    June 2021
    February 2021
    January 2021
    December 2020
    November 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    February 2020
    January 2020
    December 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    November 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    February 2018
    January 2018
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    May 2015
    April 2015
    March 2015
    February 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    December 2012
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    April 2012
    March 2012
    February 2012
    January 2012
    December 2011
    November 2011
    October 2011
    September 2011
    August 2011
    July 2011
    June 2011
    May 2011
    April 2011
    March 2011
    February 2011
    January 2011
    December 2010
    November 2010
    October 2010

    Categories

    All

    RSS Feed