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Basic technique
Reproducing Pearl Inlay
© Frank Ford, 4/14/01; Photos by FF

It's just as the sculptor said, "You take big block of marble and chip off all the parts that don't look like an elephant." At its simplest, apart from the artistry of the design and selection of materials, inlay consists of cutting out little pieces and sticking them into matching holes.

Here's how I go about a typical restorative inlay project.

The guitar on the bench was a 1929 Martin 00-40H, a Hawaiian model which was originally made with flush frets and a thin flat fingerboard, along with a high bridge and nut for slide playing. This particular guitar went back to Martin for conversion to standard Spanish style.

It got a new radiused fingerboard, along with new tuners and the appropriate setup at nut and saddle. Unfortunately, the work was done in the 1960s, when Martin was not doing any fingerboard inlay apart from simple round dots. My part was to finish the job by adding in the appropriate "snowflake" inlay.

Fortunately, I had access to this guitar, a 1924 00-42. Looking it over, I could see that it was in original condition and had the usual fingerboard inlay made of abalone. Unlike modern Martin snowflakes, these old-timers were made using the palest portion of the abalone shell. In fact, they look nearly like mother of pearl, only not as white and shiny.

My first task was to make accurate tracings of the original inlays. I stuck some pieces of thin clear self adhesive Mylar (the stuff we often use for clear pickguards) over the inlay.

And, roughed the surface just a mite with 800 grit sandpaper to cut down the glare.

I wanted a much sharper line than I could get with pencil and tracing paper, so I carefully scratched the surface with a highly sharpened scriber.

After rubbing a bit of pencil lead into the scratches, I cut the Mylar so I had a separate tracing for each inlay piece.

Then, I placed the Mylar tracing on an appropriate piece of .060" thick pale red abalone. You can see that my tracing is just as lopsided as the original inlay. After all, we're going for that "original handcraft" look here.

Here's my little inlay cutting board. It's a piece of 3/8" thick aluminum with a saw kerf cut into it. The aluminum was just some scrap I had lying around which is why there's a big notch cut out of the portion that's screwed to a maple block for clamping into my vise.

The only "special" part of my inlay cutting rig is my jeweler's saw. It's a typical one, just like the ones most folks use for this job. I've found I can keep my cut more perfectly vertical if I attach a long rod to the handle and have it riding in a PVC tube beneath the cutting platform

Then, turning both the work piece and the saw as I go, I can maneuver my cut with fair precision, just grazing the scribed line. Generally, I like to use a #2/0 jeweler's saw blade for good clean cuts.

Here they are, all ready, positioned on top of the original fingerboard for comparison. I don't have any photos of me truing up any ragged cuts with little files, but I did some of that cleanup work.

After pulling the frets and sanding the fingerboard a bit to clean and true it up, I was ready to inlay. The little squares were the easiest. I just drilled a round hole the same diameter as the width of the squares and used my 3mm chisel to cut in the corners.

Here's a square in its recess. I spent a fair bit of time measuring the width of the saw kerf in the square and found a little backsaw blade that cut that same width. Most reproductions, including Martin's current work, have smaller cuts, and the squares don't look just right, to me, at least.

The more complex shapes required a bit of extra effort. I tacked them down with tiny drops of cyanoacrylate, and scribed as closely as I could with the pointy little X-acto #11 blade.

Then, rubbing some chalk in the scratches, I was able to get nice bright lines.

Setting my Dremel router base to the appropriate depth, I used a 1/16" bit to cut the recesses for the inlays.

After trial fitting, and touching up the recesses with Dremel, knife and chisel, I stuck the inlay pieces in with a mixture of lampblack and medium viscosity cyanoacrylate. I've found that epoxy tends to soften with heat and handling, and the cyanoacrylate stays much more inert.

Using my old favorite fingerboard sanding block, I leveled the inlay and filler, finishing up with 320 grit before refretting
Notice that this replacement fingerboard is flat sawn, rather striated ebony, more characteristic of the 1960s than the 1920s.
Here it is, all done. It looks pretty much like the original, apart from the fact that the inlay is perfectly level and not as dull as the 1924 00-42.
All in all, this is a fine vintage guitar, and after replacing the gears with those really cool Waverly bronze and ivoroid numbers, it has the "right" look once again.