CA Guitar Repair Blog: Kawai MIJ Folk Guitar Gets Some Help

Friday, May 16, 2025

Kawai MIJ Folk Guitar Gets Some Help | Part 2

A New TUSQ Nut

The owner of this Kawai MIJ Folk Guitar had requested that the stock plastic nut be upgraded. To this end, he'd already purchased a TUSQ PQ-6143-00 Slotted Nut, bless him. Strangely enough, the stock nut had simply been glued on, kept in place by the truss rod cover. As such, I needed to cut a snug-fitting slot for the TUSQ nut. Here's where my Tamiya Craft Saw and StewMac Saddle Slot Levelers came in really handy.

Cutting a New Nut Slot

Test-Fitting the TUSQ Nut

Installing Replacement Tuners

I'd already reamed the stock 6 mm tuner mounting holes to fit the replacements, which were 10 mm in diameter. There was lots more to be done before the upgrade could be completed, though. First of all was plugging the old tuner screw holes. This was accomplished with bamboo skewers and super glue.

Old Tuner Screw Holes Plugged

Bamboo Plugs Trimmed and Leveled

As the leveled plugs contrasted a little too much with the finish on the back of the headstock, they were darkened with StewMac ColorTone #5033 (Medium Brown) liquid stain. Stain application was followed by another seal coat of super glue, light sanding and leveling; and a top coat of Minwax Antique Oil Finish tinted with #5033 liquid stain.

Staining the Leveled Plugs

Sealing with Super Glue

Applying the Top Coat

Once the top coat had cured sufficiently, I was able to fasten the six replacement tuners and align them with one edge of a long hex wrench as a guide. A hex wrench works much better than a ruler for this purpose, let me tell you. Pilot holes for the new mounting screws were then drilled, and the tuners fully installed.

Tuners Installed - Back of Headstock

Tuners Installed - Headstock Face

Bridge and Saddle Work

Right then, let's discuss bridge and saddle work. I'd long since abandoned the idea of using the TUSQ 9025-00 Acoustic Saddle Slab provided by the owner. Now, although it fit the oversized saddle slot perfectly, trimming it down to size would be a sheer waste of good TUSQ. And so, after lots of discussion, it was decided that we go with a buffalo bone saddle instead.

Bone Saddle in the Oversized Slot

All well and good, but what about that gap all around the saddle? Good question, and here's the answer. Well, I initially planned to fill the voids with strips of Chinese blackwood but eventually found a less labor-intensive way, which would, unfortunately; sacrifice a new rosewood bridge.

What I ended up doing was cutting out the saddle slot of said "sacrificial bridge," trimming it to shape; and gluing it into the existing oversized slot. Of course, this task involved lots of measurements, filling, sanding, and scraping; but I believe you'll agree that the results were worth the effort.

New Rosewood Saddle Slot

Next up was fitting the bridge pins. As anticipated, the replacement black bridge pins with abalone dots were way too large to be inserted fully into the existing holes. And so, a reaming we did go. But just a few turns, mind you. Now, these black beauties fit the way they were supposed to.

New Bridge Pins Do Not Fit

Reaming in Progress

Now They Fit Nicely

Mini Photo Shoot

Folks, an oversight has led to a few details being omitted from this post. These include bridge ramping, where I cut slots running from the front of each bridge pin hole towards the saddle. This would allow for proper string break angle, even with a substantially lowered saddle. The buffalo bone saddle was also lowered to reduce string action. Yes, this involved a bucketload of measuring, sanding, rinse and repeat; ad nauseam. Subsequently, the Kawai was strung with Gibson SAG-MB10 Super Ultra Lights before final setup. 'Nuff said, then. Time to join me on a mini photo shoot. Note: These images were captured this morning.