How a Tibetan singing bowl is made
Seven metals, a coal fire and about a thousand hammer blows. A look at how our bowls are shaped by hand in a Patan workshop.
A singing bowl starts as a flat disc of bronze, and ends up a bowl only because someone hit it several thousand times in the right order.
The alloy
The bowls we stock are cast from an alloy the workshops call panchadhatu — literally "five metals". Copper and tin do the acoustic work; the rest is tradition as much as metallurgy. The ratio matters more than the recipe: too much tin and the disc cracks under the hammer, too little and the bowl thuds instead of sings.
Heat, hammer, repeat
The disc is heated in a coal fire until it glows a dull orange, then worked cold until it stops moving. Then it goes back in the fire. A four-inch bowl takes maybe fifteen of these cycles; a large one can take fifty.
You are not shaping the metal so much as persuading it. Rush it and it tears.
Three or four people work a single bowl at once, hammers falling in rotation. The rhythm is not for show — it keeps any one spot from being struck twice in a row and thinning out.
Tuning
Nobody tunes these to a chromatic scale. The note is a consequence of the wall thickness, and it is found rather than chosen: the smith taps, listens, takes a little more metal off the rim, taps again. Two bowls from the same workshop on the same day will not be the same pitch, which is the point.
What to look for
Hammer marks should be irregular. Perfectly even dimples mean a machine press, and a machine-pressed bowl has a shorter, flatter sustain. Hold the bowl on an open palm — not gripped, which damps it — and run the mallet round the outside rim at a steady walking pace. A good bowl takes a few seconds to find its voice, then holds it long after you stop.