A hammered surface is only one part of a copper vessel’s manufacture. Gyokusendo’s process reference describes shaping through repeated hammering and annealing, before the later decorative and colouring work.
Technique and structure
The maker says copper hardens as it is hammered. Annealing restores softness during production, allowing shaping to continue. For raising, a torikuchi iron stake supports the copper while a hammer progressively narrows the vessel’s opening. The sequence links the metal’s changing working condition to the developing form; it is not simply a pattern of decorative dents added to an already finished vessel.
Do not turn one example into a universal count
Gyokusendo gives about 15 repetitions of hammering and annealing for a kuchi-uchidashi kettle, whose spout is raised from the same sheet without a seam. That is an example for a named construction, not a promised count for every copper object.
For international readers
This is an account of professional manufacture, not home heating or repair advice. Confirm lining, finish and permitted use for the actual product.
Global shipping and buying
Current inventory and international delivery are unverified. No affiliate links are used.
日本語
鎚起銅器：打ち絞りと焼きなましを繰り返す理由
玉川堂は、銅板を鎚で縮めながら器の形を作り、硬くなった途中材を焼きなまして柔らかさを戻すと説明します。鳥口を支えに口径を絞る成形と、最後の鎚目や着色は別の工程です。特定の湯沸の例に挙げる約15回を、全製品共通の回数とは扱いません。