It can take some time to create jewellery using Repoussé and chasing, although with practice, complex and delicate pieces can be made which would be virtually impossible to complete using any other method. It takes a lot of time due to the repetition of a number of time-consuming stages: the preparation of a sheet by annealing; cleaning to remove the pitch between annealing and work; setting up; and careful work with punches. One method of repoussé and chasing is to place a thin sheet of metal on a bowl of heated Pitch. The pitch is slightly soft, and hardens when cooled, or becomes liquefied when heated. The purpose of using pitch is to provide a solid base to work on, whilst allowing the metal to be pushed out and shaped without obstruction. The pitch is best worked on in a pitch bowl. This is a cast iron bowl which sits on a bag stuffed with sand or a similar substance. This allows for greater stability, rotation and angling. The pitch is heated using a hairdryer, or an industrial blowdryer. If the pitch is too hard, the metal will be thinned. If it is too soft, you have very little control over the form. Good pitch is hard enough to hold its shape, but soft enough to yield.
Steel tools are used to work the metal. A "liner" is a steel rod with a very thin, slightly rounded end, that is used to create the initial lines on the metal. The liner is hit on the end with a chasing hammer, pushing a thin line of metal into the pitch. The side facing up will consequently be the front of the piece. Once all the lines have been chased, the metal is then turned over on the pitch, and repoussé is then used to push the metal so that it extrudes on the front of the finished piece. The piece of metal is turned and worked many times, with numerous tools, before the final design is achieved.
Once a fairly large shape is inverted, it can be filled in with warm pitch to help maintain its shape. The pitch should be allowed to set in the forms before the piece is placed back on the pitch. Every time the metal is removed from the pitch bowl, it needs to be cleaned and re-annealed. Turpentine is used to remove the pitch, and a blow torch can also be used to burn it off.
There are hundreds of tools which can be used. They are generally made by the jeweller/crafts person. They are typically made from bars of tool steel, which is forged and tempered at the tip. A saw can be used to cut designs into the tip for making patterns, or the tool can be hammered onto a patterned surface, which will indent the tip. The end of the tool which is to be hammered should be bevelled to allow for expansion of the metal from repeated hammering. Some of the main styles of tool include: Liners, planishers, matting, and doming. Liners have thin tips, which are slightly rounded. If they are too thin they will cut the metal. They are used in the initial marking out of the design, and in the finishing stages to refine any thin outlines. Planishers have smooth, flat tips which are used for pushing out large, flat areas of metal. Matting tools have patterns cut into them, and provide detail to areas of the design. Matting tools can also be made by filing a thin line around a steel bar, hardening it, then snapping it. This will result in a fine grain pattern. Doming tools push out rounded areas of metal, and can either be round or oval, quite pointed or almost flat. An oxyacetylene torch is required for heating the steel sufficiently for forging. The more tools available, the easier it is to create a detailed, accurate piece.           

 About our company
First-rate Mold Solution Co., Ltd. in China, provide industry design,mold design,mold manufacturing,molding analysis,project management service.
  About our website
our website has a lot of professional knowledges in mold industry in blog and news, also we are interested in CAD/CAM/CAE, AUTOCAD,NX,Moldflow,we welcome professional engineer,mold maker and someone who are interested in injection molding,plastic product,injection mold and mold industry to our section of blog and news,we would like to share with them