When it comes to neck construction, stability is the name of the game! Even the subtlest movements away from a true, straight condition can negatively impact the guitar’s playing action. The neck has to withstand the effects of humidity, temperature, storage (sometimes, poor storage), string tension, age, and just the act of being played. Here are some building considerations to help give your next instrument a fighting chance!
Grain orientation. It is considered common knowledge that a quartersawn neck is going to offer the most stability, but many admit that it is just one factor of many (listed below). Necks woods, in particular, Mahogany, are being cut from increasingly smaller trees which has the effect of lowering the yield of quartersawn material and driving up the price significantly. Accordingly, factory guitars (including many high-end models) have relaxed their insistence on perfectly quartersawn grain on their necks. If other aspects of the necks are attended to, the neck should not be susceptible to unwanted motion. Witness the millions of Fender electric guitars made from flatsawn material!
Here at Luthiers Mercantile, our 1st-grade necks feature straight grain and are delivered from the suppliers as “quartersawn” though the majority depart noticeably from “perfect quarter”. This is the “new normal”, and by paying attention to all aspects of neck construction does not pose a compromise to the stability to the finished neck.
Species. Genuine Honduran Mahogany is well known for its stability, handsome grain, and workability. Few woods are as easy to carve. This is due to its unique interlocking grain but, as noted above, Mahogany supplies are challenged and there are CITES regulations that prohibit easy export of this material outside of the country. Fortunately, there are many good alternatives. Maple has been a common and reliable choice for electric guitars, and less occasionally, acoustic guitars, even though its reputation for stability is not great. Just stick to the other guidelines, and you will do fine with it. Another challenge is using figured woods for necks. Who can deny the temptation to build with some lovely flamed material? Just be aware of the fact that figure is a phenomenon related to varying grain direction, which can compromise stability.
Wood preparation. There is no substitute for proper drying and storage of the neck wood. At Luthiers Mercantile, our shop manager Joel brings over 23 years of experience to bear on the careful preparation and inspection of all our neck woods. Once received, we advise that our customers allow the wood to become acclimated to their (presumably humidity controlled) shop for a week or two before building. See this page of our Help Center for guidelines. https://www.lmii.com/blog/2017/10/07/wood-drying-and-storage/
Joinery. Poor joinery can build tension into the neck. As with any joint, make sure that all parts are fitted together perfectly before gluing. This is especially true for the critical fingerboard glue-up as the fingerboard (which, like the neck, should be properly prepared) can be a great aid to stability. Some builders prefer to use epoxy on the neck as most other glues are water-based and they do not want to introduce water into the neck. Many others, however, consider this to be “overkill” and prefer the standard glues as they are more easily repairable in the event of a mishap down the road.
Laminations. Increasingly, luthiers are looking to laminate their necks. For some, this can add a cosmetically pleasing aspect to the instrument, in addition to the increased strength and stability that laminating creates. Many builders start with flatsawn blanks, split them and lay the opposing faces together to create a “faux” quartersawn grain orientation.
Carbon Fiber Reinforcements. Luthiers Mercantile is the leading supplier of these popular additions to neck construction. In addition to increasing peace of mind when it comes to neck stability, some have noticed that their addition helps eliminate “dead spots” in the neck.
Truss Rods. We at Luthiers Mercantile are tremendously proud of our patented line of truss rods. These industry-standard rods are found in notable high-end instruments throughout the world. Each of the LMI rods is made and inspected in the USA. You can find cheaper models on the market (and a few misfired knock-offs) but we invite you to go with the best when choosing this critical component. For more info, see this article https://www.lmii.com/blog/2019/07/03/lmi-truss-rods/ . This article will help you with proper installation: https://www.lmii.com/blog/2016/12/08/10-ways-to-avoid-truss-rod-disasters-december-2016/