Maxed out truss rod

Let’s face it: professional guitar techs don’t exactly have a stellar reputation. Many of us (myself included) have gone in to some shop somewhere and and paid good money to have our instrument worked on, only to have it come back even worse than before. While I don’t think that every self-proclaimed guitar expert out there is purposely setting out to screw people over (there are far more lucrative ways  to scam people outside of guitar repair…), I think a lot of bad work comes out of well intentioned shops that simply don’t have the training, skill, nor the proper tools. Unfortunately, I am oftentimes faced with the task of fixing bad work done elsewhere. I really hate getting into these kind of conversations: I don’t want to be the harbinger of bad news – especially since what I do is somewhat esoteric and difficult to explain. Moreover, I don’t like throwing anybody under the bus. But sometimes I have to call ’em as I sees ’em, and today I had to fix up a 1968 Fender Jazz Bass that has probably seen tons of bad work over the years.

This wonderful bass is owned by Dean, a very busy bass player who can regularly be seen playing on Bourbon St. in New Orleans. While the bass sounds and looks great, it’s playability left a lot to be desired. It had been refretted several times over the years, and whoever worked on it before apparently made some rather significant judgement errors. The fingerboard had been planed very thin towards the neck’s heel, and had been re-radiused to 24cm (9.5″) which is quite a bit flatter than it’s original 18cm (7.25″). You can see in the picture below that the fingerboard right above the truss rod nut is almost completely gone. Yikes!


This bass has been refretted at least twice, and I’m assuming each time the previous tech must have planed the fingerboard, but apparently didn’t take into account string tension on the neck while doing the work. When a neck is under string tension, it pulls forward, introducing relief away from the strings, but when the neck is relaxed, oftentimes the neck will backbow, creating a large hump in the middle of the neck. The previous tech must not have been using any sort of neck jig (which synthesizes string tension on the neck), and just leveled the board on the bench – which means that they removed a ton of fingerboard material from the middle of the neck. The result? Way too much relief, even with a maxed out truss rod.

Now, a neck needs to be fairly straight in order to get it playing well (between .10mm and .15mm relief). This neck had almost .25mm relief, and very uneven frets, so it was playing pretty poorly. Even with high action, it was pretty buzzy. I recommended a Heat Press and a Fret Level / Setup, which would get it in fighting shape. Since the truss rod was maxed out, and couldn’t get the neck any straighter, I first did a Heat Press on the neck, which I set up to introduce a good bit of back bow with no string tension and the truss rod completely relaxed. This sets the neck up so that when string tension is applied and the truss rod is set, it should be able to be adjusted to where I wanted it. A heat press is essentially this in a nutshell: the neck is clamped onto an aluminum beam, which is heated for about 45 minutes, which then slips the glue joint between the neck and the fretboard, and when it cools it mostly stays in the same shape that it was clamped into. Pretty slick, no?


The heat press was a success, so I moved on to leveling the frets. The truss rod nut was completely buried in the neck, and even with the added maneuverability gained with the heat press, the truss rod nut didn’t have much thread left to work with. So I made a steel spacer, put it under the truss rod nut, and presto! Even more truss rod functionality!

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Now that the neck was able to be adjusted properly, I set the bass into the neck jig and started leveling the frets.


Man, these frets were all over the place! No wonder it wasn’t playing well – who ever had refretted this bass must not have leveled the frets properly. I adjusted the neck dead straight, set up the neck jig to simulate the string tension on the neck, and then used a long flat leveling beam to hit the frets. Check it out – even the first few passes with the beam show where the high frets are:


You can see that fret dust is starting to accumulate near the headstock and near the body, but there’s nothing in the middle. Again, it appears that somebody must have worked on these frets without taking string tension into account, and took way too much material off the middle of the board.

Several passes later, more uneven frets began to reveal themselves. I took some closeup pictures of some of the problem spots. You can very clearly see that the leveling beam is not hitting all the frets, which goes to show how far off this fret job was:

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This one is quite revealing – this whole section in the middle of the neck hasn’t even been touched!:IMG_1941

Fortunately, these frets were very large, so even after the Fret Level they weren’t too low. I was able to get all the frets even with each other, complete a setup on the bass, and now it plays better than ever! Right on!


The feel of the bass has changed pretty dramatically, so it may take a little getting used to the new low action. As with all of my work, I guarantee results that you’re satisfied with, and allow for an ample grace period for musicians to play their newly setup instrument and get back to me for any tweaks. It’s important for me that things are done right for the individual player – an adjustment period is part of what you’re paying for.

Integrity and honesty is something I strive for in my work. You and your instrument deserve to be treated with respect, and there’s just no excuse for bad work. It’s too bad that this beautiful bass has been mistreated, but all’s well that ends well. It plays great now! Too bad I have to give it back…


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