Notes from the workbench: Connecting the dots

I've been working on several vintage flutes recently that suffer from the same issue: a crumbling, whitish bore filler. We often call this Seko-ji (plaster-based ground). It was used as a faster alternative to the traditional Tonoko powder & Urushi mix.

I was curious about the history of this practice, so I pulled a book from my shelf: 'Shakuhachi Making' by Kamizuki Enzan. The original text dates back to 1933 (Showa 8).

In the book, the author explicitly writes: “I use 'Sekko-ji' (plaster ground)... because it dries faster and is convenient in various ways.”

It is worth noting that the author belonged to the Tozan Ryu, a school known for its modern approach to the instrument. While I don't know if this technique was exclusive to them or widespread across all schools at the time, it is fascinating to see that the shift toward 'convenient' materials started as early as the 30s.

Decades later, we can see the result: the plaster degrades and crumbles inside the bamboo, especially if cracks develop. Just a small piece of history I wanted to share from the workbench!

P.S. This wasn't the only 'modern improvement' that backfired. Later on, some makers started using PVC for the joint (Nakatsugi) instead of bamboo. I've seen some nasty breaks in those as well... but that is a story for another post.