Planishing
Planishing (from the Latin planus, "flat")[1] is a metalworking technique that involves finishing the surface by finely shaping and smoothing sheet metal. This is by hammering with a planishing panel hammer or slapper file against shaped surface called a planishing stake that is held in a vice or a mounting hole in a blacksmith's beak anvil,[2] or against hand held shaped metal tools that are known as Dollys or Anvils. The shape of the stake or dolly has to match the desired work piece contour, and so they come in a complex variety of shapes. Alternatively, planishing may be done by the use of an English Wheel. Metal workers use planishing for surface finishing, after shaping and smoothing an object after approximately forming it, by stretching with other techniques, such as sinking and raising. Planishing is a hand driven process used in auto body repair and sheet metal craft work such as medieval armor production.
Common tools used for planishing include panel beating hammers, slappers, and neck hammers[3] 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.[4] A worker, using repeated, relatively soft glancing blows, smooths the metal toward the curvature of the stake. If the metal begins to looks dimpled, the worker is using too much force in individual hammer blows.[4]
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.[5] Pneumatic (air powered) Planishing Hammers strike hundreds of blows per minute.
Care must be taken not to allow sheet metal to work harden and become brittle during planishing. If it does, it must be annealed.
[edit] References
- ^ McCreight, Tim (1991). The Complete Metalsmith. Worcester, Massachusetts: Davis Publications. p. 61. ISBN 0-87192-240-1.
- ^ Price 2000, p. 179.
- ^ Payne, Arthur F. (2003). Art Metalwork with Inexpensive Equipment. Gustav's Library. p. 64. ISBN 0-97589-142-1.
- ^ a b Dettelmach, Gundobad von (January 13, 2009). "Planishing". http://www.armourarchive.org/essays/planishing/.
- ^ Price 2000, p. 79.
[edit] Bibliography
- Price, Brian (2000). Techniques of Medieval Armour Reproduction. Boulder, Colorado: Paladin Press. ISBN 1-58160-098-4.
