For decades, blues and rock guitarists have been laying glass or metal cylinders across their strings to add expressive riffs to their music. Unlike a Dobro or lap steel, which is played horizontally with a bar and has its strings jacked up way off the fretboard, a standard 6-string guitar can be set up for both fretting and slide work—if you know what you’re doing.
Let’s explore how to finesse a guitar so its strings sit high enough to keep a slide from crashing into the frets, yet remain close enough to the fretboard that you can play chords and riffs with your fingertips. Yes, you can have it all, as Duane Allman, Johnny Winter, Sonny Landreth, Ry Cooder, Derek Trucks, and many other greats have proven over the years.
It’s not too hard to set up an electric guitar for dual duties, so that’s what we’ll focus on. It’s more of a challenge with an acoustic, but with a little ingenuity, you can also adapt the following techniques to a flattop, so read on.
Project overview. To illustrate the steps, I’ll use a 2003 Gibson Les Paul Studio (Photo 1) a client brought in to have converted into a ripping slide guitar. He wanted to stick with his moderately light .010–.049 strings so he could comp and solo as usual, but he also wanted to augment his standard riffage with slide licks when the spirit moved him.
To make this happen, I suggested he use a lightweight, straight-wall glass slide—similar to Allman and Trucks—as opposed to the heavier brass or bottleneck slides that are often favored by acoustic resonator guitarists. Why? Using a lightweight slide, such as a Dunlop Derek Trucks Signature medicine bottle or the aluminum BigHeart Firecracker, makes it possible to use slinkier strings and keep the action reasonably low. Heavier slides can sound great, but they demand stouter strings and stiffer action. A light slide allows you to find that sweet spot in your setup where you can use the same guitar for two very different techniques.
Preliminary measurements. The first step is to measure three things: action at the 12th fret, neck relief, and string height at the 1st fret. These measurements will provide a baseline to work from.
Here’s the process: To measure the action, first tune to pitch (this is crucial) and then place a capo on top of the 1st fret. Next use a precision metal ruler to measure the string height at the 12th fret. I use a String Action Gauge—a handy tool from Stewart MacDonald—(Photo 2) for this. You want to determine the distance between the top of the 12th fret and the bottom of both the 6th and 1st strings.
On this Les Paul, the gap was 3/64" for the 1st string and 4/64" for the 6th. This action is comfortable for my client, but too low for slide.
Now to measure the amount of relief. With the capo still on the 1st fret, hold down the 6th string at the last fret and measure the greatest distance between the bottom of the string and the top of the frets (Photo 3).
On my client’s guitar, the relief was .012"—perfect for his current playing style and also fine for supporting a lightweight slide. If your guitar has less relief, you may need to loosen the truss rod very slightly to introduce a tad more forward bow. (Read “Time for a Neck Adjustment?” to learn more about working with a truss rod.) But before you take that route, first complete the setup I’m about to describe. It’s quite possible these steps will be all you’ll need to enter the slide zone.