![]() ![]() My favorite serious molding plaster is Vel-Mix, the material used at the dentist to make very hard (usually pink) models of your teeth and gums. Jewelers have forgotten how useful plasters can be for certain problems, especially low relief duplicating. Rather than making a positive a mold can be made from an object (the mold is now a negative), and wax poured into it for casting. Usually they would be painted with lacquer to harden the surface and make them last, and you can find examples that have inventory numbers carefully lettered on, so it is clear that this is how designs were organized. ![]() Then plaster of paris would be poured into the walls, and when the plaster hardened there would be the three views of the ring in positive relief, and the jewelry could be duplicated later by referring to the plaster model. A quick wall of clay or paper would be made around the clay slab with its impressions. Thus a ring would have its front, side and top with settings pressed in. There would be three views pressed in, top, side and front view (just like an orthographic projection drawing). In the old days, before easy rubber molds, a goldsmith would record their work for posterity when it left the shop by making an inch thick slab of clay or plasticine, then pressing the unset piece of jewelry into the clay. This article touches on a couple of methods for when you really need to make a mold and don't have the right molding materials on hand. There are all sorts of vulcanized rubber molds, silicone molds and others which are intended for specific problems, in fact there are dozens of them. Usually wax is poured into the molds and the results used for casting. Jewelers need to make molds of objects and parts frequently. By Charles Lewton-Brain More from this author ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |