Planishing (from the Latin planus, "flat")
Process
A metal surface is finished by hammering it with a planishing panel hammer or slapper file against a shaped surface called a
planishing stake that is held in a vise or a mounting hole in a blacksmith's beak anvil,
[.] or against hand-held, shaped, metal tools that are known as
dollies or
anvils. The shape of the stake or dolly has to match the desired work piece contour, and so they come in a variety of complex shapes. Alternatively, planishing may be done by the use of an
English wheel. After approximately forming a metal object, by stretching with techniques such as sinking and raising, and then shaping and smoothing an object, metal workers use planishing for surface finishing. Planishing is a hand-driven process used in auto body repair and
sheet metal craft work such as medieval armour production.
Tools
Common tools used for planishing include panel beating hammers, slappers, and neck hammers.
Heavy rawhide or hardwood hammers are often used. It is more difficult to make mistakes with heavy rawhide or wood mallets, but they are less effective for large imperfections.
A worker, using repeated, relatively soft glancing blows, smooths the metal toward the curvature of the stake. If the metal begins to look dimpled, the worker is using too much force in individual hammer blows.
Features
Since planishing hammers are generally in contact with the outside surface of the piece, they are flat, have rounded edges and are polished to avoid marring the work.
[.] Pneumatic (air powered) planishing hammers strike hundreds of blows per minute.
[ Air Planishing Hammers, Grainger, lists hammers available with 1800 to 5400 Blows per Minute, accessed 10 June 2020.]
Care must be taken not to allow sheet metal to work hardening and become brittle during planishing. If it does, it must be annealed.
Notes
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