Photo 4 — Photo by Andy Ellis
Taking stock. Before you buy a bone blank, you’ll need to do a little homework. Saddle slots are typically 1/8" (almost 3.5 mm) or 3/32" wide, and blanks are cut accordingly, so you’ll need to determine which size is right for your guitar.
First remove the strings and stash the bridge pins where they won’t get lost. Next, carefully lift the original saddle from the slot. If you’re lucky, you’ll be able to coax it out with your fingers, but if the saddle won’t budge, pad your guitar top with a few hand towels and use a small pair of pliers to gently rock the saddle out of its slot. Go slowly and carefully. If the fit is really snug, use an object with a narrow, pointed metal tip (a dental tool works well) to gradually pry the saddle up from one end of the slot. From there, use the pliers to complete the job. Save the original saddle so you can quickly reconfigure your guitar for fretting again in the future.
Now measure the saddle slot width (Photo 4). If the gap falls between 1/8" and 3/32", buy the thicker 1/8" saddle and plan to shave off a little width by rubbing the blank lengthwise along a piece of fine sandpaper or against a large flat file. Most saddle blanks are purposely oversized, so expect to sand down the width a little to fit the slot. A saddle blank will set you back less than $10 and is available from eBay vendors and luthier-supply outfits.
Note: Some blanks are curved on top to match the fretboard radius, but that’s not what we’re after here. Be sure to get a blank with a level top because you want the strings to rest in a flat plane and correctly match the playing surface of your bar.
Photo 5 — Photo by Andy Ellis
Shaping the saddle. Once you’ve got your saddle blank, you’ll need to trim it lengthwise. Measure the saddle slot (Photo 5), mark the saddle, and use a small hobby saw (Photo 6) to remove the excess length. Take your time and watch your fingers.
Photo 6 — Photo by Andy Ellis
To prevent the string windings from separating and the plain strings from snapping as they emerge from the bridge-pin holes, put a gentle slope in the saddle’s rear side with a small flat file (Photo 7). Easy does it—you don’t have to remove much. Keep the saddle’s top surface level and maintain a crisp right angle on the leading edge where the strings head toward the soundhole.
Photo 7 — Photo by Andy Ellis
Protect your picking hand from any sharp edges by rounding off the two corners that will be exposed when the saddle sits in its slot. When you’re done, polish the saddle with 1500 grit micro-fine sandpaper and slip it into the bridge.
Stringing up. Lap slide guitarists often play in open G or open D (check out this story’s sidebar, which lists major and minor forms of both tunings). Because they’re pitched lower than standard tuning, you can slap a burly set of strings on your acoustic without fear of damaging it. A set of medium-gauge (.013-.056) acoustic strings sound great for these dropped tunings, and mediums do a better job of supporting the bar than a light set—another advantage of going up a gauge.
Photo 8 — Photo by Andy Ellis
Before you install the extension nut, put all six strings on the guitar. Tighten them enough so they align, yet leave some slack so you can lift the strings and slide the arched nut over the original nut. Photo 8 shows a finished saddle installed in the bridge. Notice how the strings hug the rounded back of the saddle as they rise through the top, and how they leave the saddle precisely at its perpendicular front edge.