Whether you’re trying to achieve the perfect set-up for your guitar, or just trying to get rid of some annoying feet buzz, learning how to fix a back bowed guitar neck is an important skill that can help you get the best sound out of your guitar!
A simple hack to fix a back bowed guitar neck is to heat the surface of the fingerboard for about 15-20 mins. This will result to melt the glue between the fingerboard and neck and ultimately neck will bend forward.
Another method to fix the back bowed guitar neck is to use a truss rod. In this article, we’ll show you how you can easily fix a back bowed guitar neck —simply by adjusting the truss rod of your guitar!
How to identify a back bowed guitar neck?
A back bow on a guitar neck results when the fretboard of your guitar is bent outwards, pushing the center of the neck towards the strings. This causes the guitar strings to get too close to the fretboard, resulting in fret buzz.
Before you make any adjustments, it’s important to make sure that the neck of your guitar is back bowed. There are several ways you can check for a back bowed guitar neck.
Firstly, you can identify a back bowed guitar neck by listening to how your guitar sounds. A back bowed guitar neck decreases the distance between the strings and the fretboard, causing the strings to buzz when playing along the center of the guitar neck. If there’s a lot of buzzing on your guitar when you play notes, chances are that your guitar has a back bow.
Often, it may even be possible to simply “eyeball” a back bowed guitar neck.
Simply place your guitar on its side and see if you can notice the headstock being bent backward and the middle of your guitar neck being pushed outwards —towards the strings.
However, to check precisely for a back bow, it may be a good idea to check the distance between your guitar strings and the fretboard.
To do this, simply put a capo on the first fret of the guitar, and place a finger on the low E-string on the fret which is right on top of the joint between the neck and the body of the guitar.
Check the distance between the low E-string and the fretboard on the fret halfway between the capo and the fret where you’ve placed your finger. This distance should be around 0.010 inches.
You can use a feeler gauge of 0.010 inches to measure this height or use a business card to approximate it. If there is no space between the strings and the fretboard, your guitar most probably has a back bowed neck.
How much does it cost to fix a warped guitar neck?
This mainly depends on the nature of the back bow, and the time required to make the adjustment. In the case the guitar simply requires a truss rod adjustment, it can cost anywhere between $10-$20.
However, if the neck is warped significantly and requires heat-based adjustment, it can cost from $60 to over $100, depending on the nature of the repair required.
In some cases, you might even have to get your neck replaced. This can cost anywhere from $50 to several hundred dollars, depending on the specifications of your guitar and the finish of the neck.
Fixing a back bowed guitar neck by adjusting the truss rod
You can fix a back bowed neck by loosening the truss rod on your guitar to add relief. This is a fairly simple adjustment that you can make at home with the right tools.
What is a truss rod?
Guitar strings are generally under a lot of tension because of the way they are tuned. Since the strings are attached to the neck of your guitar, they constantly pull on the neck — pulling it forward.
The wooden neck of your guitar is prone to warping under this tension. Since the strings pull the neck from the top of the guitar (the headstock, where they are attached), and the bottom half of the neck is fixed to the guitar body, the strings tend to pull the neck of the guitar into a “U” shape. This causes the neck to warp over time into a “front-bow”, which can increase the action — the distance between the strings and the fingerboard — to increase, making the guitar difficult to play.
To neutralize this natural warping of the guitar neck, manufacturers add a truss rod inside the neck of the guitar. The truss rod is a steel rod that runs along the middle of the necks of most modern guitars. This truss rod keeps the neck of the guitar straight by strengthening the neck and preventing it from warping under the tension from the strings.
The truss rod is also adjustable; meaning that it can be tightened or loosened to adjust the amount of relief it provides. Loosening the truss rod provides relief to the guitar neck — allowing it to bend with the tension of the strings — while tightening it reduces the amount of relief provided, causing the guitar neck to “straighten up”.
Where to find the truss rod?
Usually, the adjustment point of the truss rod can be found at the top or bottom of the neck. In some guitars, you can find it right below the string posts on the headstock. It may be hidden under a small flap screwed right next to the nut. While in other guitars, it can be on the point where the neck meets the body of the guitar.
This adjustment point can be inside the soundhole, in the case of acoustic guitars, while in the case of some electric guitars it can be found right at the bottom end of the guitar neck. To access the adjustment point, in some cases, you might even have to unscrew the neck of the guitar from the body.
It’s important to note that although most modern guitars have truss rods, some guitars simply do not. This can be the case for some very old, or cheap, guitars.
How to adjust the truss rod to fix a back bowed guitar neck?
First, you need to find out which type of “key” can be used on your guitar to adjust the truss rod. Some guitars use an Allen key, while others may use a special type of Phillips head screwdriver.
You can find out which type of key your guitar uses by checking the manufacturer’s website or the user manual that came with your guitar.
Before you being to adjust the truss rod, make sure to de-tune your guitar and remove any significant tension from the neck. You don’t have to de-tune the strings to the point where they become completely slack —just enough to remove most of the tension on the neck.
Next, insert the appropriate end of the key into the adjustment point of the truss rod.
Turning the key counterclockwise usually increases the amount of relief given to the neck while turning it clockwise decreases it.
To fix a back bow on the guitar neck, you need to increase the amount of relief given to the neck, i.e., turn the key counterclockwise. If you’re a beginner, only adjust the truss rod by ¼ of a full turn at a time. Re-tune your guitar and check if there’s any significant difference in the distance between the strings and the fretboard.
Ideally, there should be a gap of 0.010 inches between the strings and the fretboard of the guitar. This can be measured by either using a feeler gauge or a business card (using the method described earlier).
Loosen or tighten the truss rod using ¼ turns, re-tuning, and checking the distance between the strings and the fretboard after each ¼ turn. Repeat this process until you’ve reached the desired level of bowing on your guitar neck.
How to fix a back bowed guitar neck without a truss rod?
In the case your guitar neck doesn’t have a truss rod, the back bow can be fixed by using heat and tension. This is a relatively complex repair that may require specialized equipment. In this case, it would be best to take your guitar to a luthier or a local guitar store.
If your guitar has a bolt-on neck, you can even replace your entire guitar neck. However, we’d recommend having a luthier take look at your guitar and weigh in before resorting to this method.
In some cases, it may even be possible to get rid of the back bow on your guitar neck by putting on some heavy gauge strings on your guitar, tuning the guitar a few semi-tones above standard, and leaving it for a few days. However, this method is unreliable and could potentially damage your guitar.
Although it may seem extremely daunting to adjust your guitar on your own, it is an essential skill that every guitarist needs to have in their repertoire. Adjusting the truss rod is a relatively simple process, and learning how to do it yourself can save you money in the long run.
As long as you adhere to any safety instructions given by your guitar manufacturer, you should be good to go!
However, In the case where the key doesn’t turn the truss rod, or if you face too much resistance while adjusting the truss rod, it is always a good idea to have a professional take look at your guitar. It’s best to be careful to avoid damaging your guitar in a botched attempt at fixing it!