Most Himalayan prayer wheels come from one place. Patan, called Yala in Newar and Lalitpur in Sanskrit, has been a metalworking city since the Licchavi period, roughly the fifth to eighth centuries. The workshops sit in the lanes around Mangal Bazaar, Oku Bahal and Mahaboudha, and the families running them are often the fourth or fifth generation in the same trade.
The work is divided by hereditary craft groups. Shakyas handle the lost wax casting. Tamrakars work sheet copper, bronze and brass, which is where a prayer wheel drum comes from. Vajracharyas, who are tantric priests, consecrate the finished object. Manadharas do the fine detailing.
Raising the drum
A drum body starts as a flat sheet of copper. The smith works it over a stake with hammers, turning the flat disc into a cylinder and then a shaped body with a lip at each end. The metal hardens as it is worked, so it has to be softened again in the fire many times before it will take the next blow.
Repousse and chasing
The lettering is not cut into the surface. It is pushed out from behind, a technique called repousse. The sheet is laid face down on a bed of hard pitch or lac, and the letters are hammered outward with blunt punches. The piece is then turned over, set back into the pitch face up, and the same lines are tightened from the front with finer punches. That second stage is called chasing, and it is what gives the strokes their crisp edges.
This is why the letters on a real mane catch the light the way they do. They are raised metal with rounded shoulders, not engraved grooves, and the high points get polished by decades of hands while the recesses stay dark.
Finishing
The surface may be left as copper, which darkens to brown and black over the years, or it may be gilded. The traditional method is fire gilding, also called mercury gilding. Gold is dissolved in mercury to make a paste, the paste is spread on the copper, and the piece is heated until the mercury burns off and leaves the gold bonded to the surface. It gives a deep colour that lasts for centuries. It is also dangerous work, since the vapour is poisonous, so it is now restricted and much of the trade uses electroplating instead.
Polishing is done with agate burnishers, smooth stones mounted on handles, rubbed over the metal until it shines.
Assembly
The printed scroll is wound onto the central rod, the caps are fitted, the top ornament is attached, and the drum is hung in its frame on a bearing so that it turns freely. A well made wall wheel should keep going for several seconds after one push.
Araniko
The reputation of this craft is old. In 1278 a young Newar artist named Araniko led a group of around sixty to eighty craftsmen, mostly metalworkers, north to Tibet at the request of Kublai Khan. He went on to the imperial court in China and became its chief architect and artist. Newar metalwork was not a local product. It was the standard for sacred art across a very large part of Asia.