If the original is made of a soft substance such as paraffin wax which can be scooped or melted out of the mould, whole-object castings can be made (vents can be drilled into the mould to prevent air being trapped). Hessian or wire mesh can be included to add strength to slender or large areas of the mould. If containment is difficult - as with a large panel, or other fixture - the mould box will have to be devised around or over the original ensuring that the junction with the sides of the box is completely sealed with plasticine, etc. ¶The mould box can be any simple plastic container or frame lined with a plastic sheet, etc., with the object being firmly fixed or suspended in the box - tupperware containers, washing-up bowls, old cardboard boxes, even plastic footballs cut-in-half are all perfect. Intricate or hollow moulds can be formed in sections which can be held together with rubber bands or tape, etc., and the joint-lines levelled off after separation. vaseline), but heavily-detailed or shiny surfaces can be difficult to part - metal, glass and ceramics all require a release agent, however flexible moulds (see below) are normally used for rigid materials and for copying originals with heavy or undercut detail. Originals made of pliable materials such as plastic, rubber, silicone and plasticine do not normally need a release agent (e.g. This may be part or all of an existing object, or a master modelled for making one or more copies, and might be a pot, a plate, a figurine or even part of a car. Making Plaster-of-Paris Moulds Although it can be sculpted as a 'negative', more usually a plaster mould is formed from an original or prototype. Unlike other types of gypsum, casting plaster is very pourable once mixed with water but sets quite suddenly, usually at somewhere between 10 and 30 minutes, depending on the particular variety. ‘Plaster-of-Paris’ can mean the powdered material, the finished work - or the art-form ‘casting plaster’ is just a more specific term for plaster-of-Paris while it is still just a powder, e.g.
All the materials mentioned below are in the drop-down menu use the tabs below this table for more about the methods. Water/weather-resistant good impression capability extremely hard surface and very resistant to breakage, chipping, etc.Ĭasting work lends itself to improvisation both with materials and methods, and it is very satisfying to see a work-of-art evolve from what-starts- off-as just a powder or a liquid. Also marble/stone repair & restoration (cast or applied).Ī particularly strong plaster. Statues, figurines, water features, sculptures and all outdoor work. Moulds or casts requiring extreme durability, or where the finest possible detail is necessary, e.g in ceramics.Įxtremely dense surface Crystacast is one of the finest pottery plasters available Herculite Stone is very chip-resistant. Suitable for life-casting if painted, etc.ĭense hard surface large casts and projections may require the inclusion of mesh or fibre, etc.Ĭasts or moulds requiring durability but also extreme accuracy often used in engineering work, musical instruments, etc.ĭisplayware, giftware, chess pieces, etc., reusable moulds slower drying in slip moulds and slightly better definition than Herculite No.2, and much-favoured for life-casting work.ĭense hard surface very popular in exhibits, displayware and undecorated life-casting because of its whiteness. Longer drying time in slip moulds but greater detail. Sculptures and casts requiring durability, reusable moulds and items likely to be handled frequently. General casting, and any situation where faster setting is required despite its name, a popular general-purpose plaster. Artists' is stronger than Fine Casting plaster. General casting and moulding suitable for a wide range of artistic applications and most large objects and impression work also fibrous plasterwork, decorative mouldings, panels, etc.ĭecorative items, occasional moulds, impressions, models, etc.
#RECIPE FOR HIGH HEAT CASTING PLASTER FIR GLASS PORTABLE#
Portable objects, giftware, reusable moulds, life-castsĮngineering work requiring extreme accuracyįigurines, outdoor work, water features, restoration Art room/workshop casting & moulding, most large pieces
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