Fig. 1 -Strap buttons come in an amazing array of shapes and sizes.
There are two critical considerations: The first is to find the right location. If strap buttons are installed incorrectly, your guitar won't balance well when you play standing up. The second consideration is to be very careful when installing a button on the neck heel—you can crack it. So, using both an acoustic and an electric guitar to illustrate the process, let's find out how to do this right and avoid those potential problems.
Our instruments.
Recently, a client brought in two guitars: a Larrivée OM-03 Vintage Sunburst and a 2002 Gibson SG Supreme. The Larrivée already had an endpin, but it lacked a strap button. The owner wanted me to install one so he could stand when playing onstage. For the SG Supreme, he wanted me to replace the stock buttons with a set of locking devices, so he could safely rock out with his band. For the Larrivée, we decided on a standard nickel-plated strap button and felt washer from Allparts; for the SG Supreme, we chose Schaller Security Locks.
One caveat.
My client wondered if adding a strap button would devalue his acoustic. On most modern flattops, a correctly installed strap button won't devalue the instrument (two exceptions are high-end vintage guitars or classical guitars). A strap button is useful for working musicians, and most guitar manufacturers will offer to install one before the guitar leaves the factory. Another reason to add a strap button to an acoustic is that tying a strap around the headstock (the old-school approach) can damage the finish, and in some cases, add unnecessary pressure to the neck joint. There's a lot of debate about this. Most collectors would never want anything installed on a guitar that was not considered original, so if you have a vintage axe keep this in mind.
Selecting the location.
Fig. 2 (left) To install a strap button on the treble side of a flattop's neck heel, you need to take two measurements. One is the distance down from the fretboard. Fig. 3 (right) The second measurement is the distance away from the body.
Let's begin with the acoustic. The first step is to decide where to install the strap button. For the Larrivée, I determined that the best location was on the treble side of the neck heel about 1 1/4" below the top of the fretboard (Fig. 2) and about 1 1/2" out from the body (Fig. 3). I selected this spot for balance and structural integrity: This placement will keep the guitar from leaning away from you when you play, and this part of the neck heel is very stout, so you won't have to worry about cracking the heel—assuming the button is installed correctly, as we'll discuss in a moment.
Fig. 4 - Mark the strap button's location by pressing the screw tip into the wood.
Once you've made these two measurements and located their intersection, mark it. You can mark the location using a pencil or gently press the strap button screw into the heel (Fig. 4).
Tip: If you use a screw to mark the drilling location, be careful not to slip—you could scratch the heel.
Selecting the drill bit.
The goal is to drill a hole that's slightly smaller than the outside diameter of the screw. If you use a drill bit that's too big, the screw will strip the wood and the button will not hold properly. Most strap button screws are relatively close in size, but they do vary depending on the manufacturer. Make sure you measure both the threads and the screw shaft so you know what size drill bit to use.
For example: The outside diameter (including threads) of my strap-button screw was 9/64", and the shaft (without threads) was about 7/64" in diameter. By choosing a 7/64" bit, I left enough wood for the screw to tap (or thread) itself into the heel without damaging it.
Gauging drill bit depth.
Fig. 5: Measure drill bit depth, then mark it with a red Sharpie.
With the screw inserted into the button, measure the depth needed for the screw and mark your selected drill bit with a red Sharpie (Fig. 5). This way, you'll know how deep to drill the hole. If you drill too far, you could hit the neck pocket. But if the hole is too shallow, you could crack the heel when you install the screw. Measure carefully and get it right.
Drilling the hole.
This is where all your measurements pay off. Remember, you don't have to push hard—let the drill and bit do the work. You simply control the process by keeping the bit aligned and watching the depth (Fig. 6).
Fig. 7: Countersinking the hole with a Phillips screwdriver.
Before you insert the screw, use a medium-tip Phillips screwdriver to countersink the hole you just drilled (Fig. 7). This prevents the finish from chipping around the hole when you insert and tighten the strap-button screw. After countersinking the hole, install the strap button with a small felt washer between the wood and metal. The washer prevents the strap button from marring or denting the finish and wood, and it looks nice.
Fig. 8: Place a felt washer between the neck and button, then slowly tighten the screw until
the button is flush to the neck heel.
Voilà—a correctly installed strap button can add utility to a steel-string guitar (Fig. 8).
Strap-locking devices.
Fig. 9: Each Schaller Security Lock consists of an integrated screw and button, a locking mechanism that attaches to the guitar strap, and a washer and nut used to secure the locking device to the strap.
There are many different types and brands of locking devices on the market, but as I mentioned, my client wanted Schaller Security Locks (Fig. 9) for his SG. Once you've selected your locking hardware, it's crucial you measure the length of the included screws that go into the body and subsequently attach to the locking mechanism. In a moment, we'll see why.
The work begins.
Fig. 10: Comparing the length of the stock SG screw and button (left) with the Schaller screw.
Installing the Schaller button on the SG's lower bout was easy because it was already pre-drilled for the original strap button I'd removed. Because the Schaller screws with their integrated buttons were longer than the original Gibson hardware (Fig. 10), I redrilled the hole to the proper depth using a 7/64" drill bit. So far, so good.
Fig. 11: The Schaller screw is too long for the SG's neck joint—it might hit the truss rod.
Ah, but the other strap button was a different story. On SGs, Gibson typically installs a strap button on the back of the guitar, right behind the neck joint. After I removed the stock button and measured the depth of the Schaller screw against the SG's neck joint (Fig. 11), I realized the screw would penetrate too far and possibly hit the truss rod. Yikes!
This left me with two choices: see if I could use the original hardware, or shorten the supplied Schaller screw and integrated button. Fortunately the Gibson button fit inside the Schaller locking mechanism, so I decided to reuse the original screw and button, rather than shorten and rethread the Schaller screw. Once again, I included a felt washer between the body and button.
Loading the strap.
Fig. 12: Attaching the Schaller Security Lock to the strap.
One of the features that makes the Schaller system so secure is that the locking mechanisms attach to your strap. It's simple: Slip the strap-lock base into the strap's slit. Place the included washer over the device's shaft. Using a 9/16" deep-well nutdriver, tighten the nut over the washer (Fig. 12). This makes it nearly impossible for the locking mechanism to slip out of the strap. Rinse and repeat.
To mount the strap to the guitar, simply pull up on each lock's post, slip the lock onto its respective button, and release the post to lock it to the button.
[Updated 10/8/21]