What does a guitar tech do when they’re not working on a client’s guitar? Work on their own guitar, of course! Today, I completed a restoration on an old Ibanez USATK, made for Ibanez by Bunker Guitars in the early 90s. I’ve been after one of these instruments for years – they only made 400 of them, and very few of them in the blue finish I was looking for. I was hunting this bass for several reasons: I didn’t have a blue bass; I wanted that Stingray sound without the harsh high-end “clank”; and I was intrigued by Bunker’s Tension Free neck system. I found this bass on Craigslist in Dallas for $400, and since I was planning on passing through there on my way from San Francisco to New Orleans, I snapped it up.
Upon first inspection of my new bass, I was pleased to discover that it had been beaten to hell and back over the years. I just love instruments that actually get used – methinks that guitars shouldn’t be kept in an ivory tower, never to be played. Unfortunately, this bass also had some pretty serious issues to be addressed, and I was in for a lot more work than I had initially thought. The frets were worn and uneven, the nut was too low and the spacing was off, and the neck had a wicked kink in the upper region. Normally, these problems are fairly standard – I do refrets and make new nuts all the time. But the design on this bass, and some hidden problems, made fixing this USATK a more arduous task.
First of all, the tension free neck system is a decidedly different way to build a neck, so standard repair practices do not apply. Here’s the design in a nutshell: instead of using a truss rod, it uses a steel bar that holds all the string tension, instead of the wood of the neck. It’s adjusted by a screw on the neck heel, and pivots against a set screw that’s inside the neck at the 16th fret. (More on Bunker’s Tension Free neck system site) It’s an elegant system, provided you know what you’re doing. And that’s where the problems start.
I strung up the bass in my usual manner: I tune my bass CGDA, using really heavy strings. I did this so I can check the neck under my own real world playing conditions, before I start any real work on it. I discovered very quickly two problems: one, that the neck wouldn’t completely straighten, leaving too much relief in the middle of the neck; and two, there was a significant kink in the neck as it joined the body. Normally, pulling the frets and leveling the fretboard would be the thing to do, but this neck has a maple fingerboard, with a beautifully distressed finish, and I didn’t want to have to sand that off. I realized at this point I was in for a lot more work, and decided to disassemble the neck – which is when I discovered yet another problem: somebody had ruined the internal set screw, and it wouldn’t come out!
Musicians are curious creatures, and when confronted with something they don’t understand, the oftentimes attempt the worst: they poke at it. In this case, the Ibanez USATK has a small hole in the neck at the 16th fret, where the internal set screw resides, and somebody poked around in there and stripped it’s head off. I got lucky removing this one: I used a reverse threaded drill bit, and was able to slowly back it out:
Once the set screw was removed, I was able to disassemble the neck. The headstock and attached steel beam just slide right out! Here’s something you don’t see too often:
The steel bar was dead straight, but the neck still had a kink at the end. I went for a two pronged attack to get the neck to the degree of straightness I was after. First, I opted to heat press the neck, with the intent of reducing the kink and flattening the neck out:
A heat press is the process of sandwiching the neck with a couple of aluminum beams and a heating element, which actually melts the glue that holds the neck and fretboard together, allowing the glue joint to slip ever so slightly and reset with the neck dead straight. It’s not a guarantee that it will eliminate problems altogether, but in my experience most heat presses are pretty successful. Lucky for me, the kink disappeared and the neck ended up dead flat. Huzzah!
Next I opted to bend the steel bar backwards, to counteract the string tension, in hopes that the backbow would equalize with the forward pull of the strings and give me a fairly straight neck. I marked out at what point the neck was at it’s greatest relief, and then set the steel rod in a vice and gave it the old heave ho:
I ended up bending the rod very slightly, as I suspected a little bit would go a long way. With these two processes complete, it was time to put the neck back together and test to see if it could handle the stress of my heavy strings. But no, wait! I couldn’t just put the old set screw back in there – it was ruined, and I couldn’t be sure if I could ever get it out again. So I measured the old screw, discovered it was a 6-32 1″ set screw, and looked all over town to find another one. Unfortunately for me, none was to be found, so I was forced to buy online, where they are only sold in packs of 100. Yes, I just paid $13 for a single tiny screw. No fun!
All this work at one $13 screw later, I put the neck back together and strung it up with baited breath. And… hooray! The neck was straight, and could be adjusted to the .10mm relief that is to my liking. From here on out it was just a simple matter of refretting the neck and making a new nut. But wait… this is the original nut:
The nut is made of one solid piece of brass, which couples directly to the steel rod, and holds the tension of the strings. But this nut was already too low, and I was about to put in jumbo frets, which the strings would never clear without a properly cut nut. I couldn’t very well machine an entirely new nut like the original, as I’m not a machinist and it would be far too complex project to do by hand. Instead, I opted to grind the nut off, leaving a perfect shelf or a new brass nut:
From here on out the work was easy-peasy: refret, new brass nut, a setup, flattening the warped pickguard, and some electronics work (I gutted the active electronics, making the bass passive). And now, after years of hunting and many hours of work, I’ve got a killer new (well, old) Ibanez USATK bass! Sweet!