How to Repair Your Bachi

Even if you take great care of your bachi, accidents happen—it might slip out of your hands and fall. If you’re very lucky, it lands in a way that leaves it completely intact, and the only damage is the shock running through your bones. But more often than not, a piece of one of the corners will break off—to a greater or lesser extent. Sometimes, a repaired corner can still be used for playing, but in other cases, so much breaks off that one side is lost forever.

If the worst happens and your bachi suffers damage from the fall, you should absolutely avoid playing with the damaged side. No matter how small and harmless the chipped area may seem, the break will have sharp edges that need to be thoroughly sanded down and smoothed out. Even if no visible damage is apparent to the naked eye, you should gently run your finger over the edges to check for any splintered areas. You’ll immediately feel if something has chipped off.

In the short term, you can simply switch to using the undamaged side. However, you should deal with the damage as soon as possible. If you continue playing with a broken corner, you’ll quickly wear down your strings—and even worse, the kawa (skin) of your shamisen could suffer damage.

When is a bachi still salvageable, and when does it need to be replaced? In most cases, this question can’t be answered definitively. How much damage is “too much” depends on personal preference and tolerance for changes in playing feel. However, even if a corner is beyond repair, you should still smooth it down to avoid injuring yourself or your instrument.

Here are some common damage scenarios:

Regardless of whether your bachi is made of plastic or wood, you can easily treat the surface using regular sandpaper. Hardware stores carry different types of sandpaper for various materials. Since plastic and wood are relatively soft, you can use sandpaper designed for any material.
It’s important to have sandpaper in different grits and to work your way gradually from coarse to fine. The back of the sandpaper package will indicate the materials it’s suited for, whether it’s for wet or dry use, and the grit size—i.e., how coarse or fine it is. The lower the number, the coarser the grit. The goal is to progress from a lower number to a higher one.

I usually start with a grit of 220 and work my way up in increments, depending on what sandpaper I have on hand, until I reach the four-digit range. You can skip a grit size here and there if necessary, but in general, patience is key. Taking it step by step ensures you avoid scratches and achieve a perfectly smooth finish.

Since you strike both the strings and the kawa with the bachi, you want the surface to be as smooth as possible. A rough surface will quickly damage both the strings and the kawa.

A fantastic tool that fits in any instrument case and weighs next to nothing is a so called nail polishing block:

You can find these blocks in the manicure section of any drugstore. They have four different levels of abrasion. The roughest side is meant for shortening nails—this removes a significant amount of material and can be used to round out sharp chips in the bachi. The next side has a finer grit, removing less material while smoothing the surface. The third stage has such a fine grit that it has a polishing effect, and the final stage brings everything to a high-gloss finish.

You’ll achieve better results by using sandpaper in gradual grit increments, but if the damage is minor or you urgently need a quick fix while on the go, a nail polishing block is a lifesaver!