|
|
Sculpting or Carving a Prototype If you are artistic, you may choose to either sculpt or carve your master prototype by hand. Sculpting and carving can be done in a variety of materials that can be readily found at arts and crafts stores. You don't have to make a model for each cavity on your mold. All you need to do is make one, then you can make replicas using the model reproduction techiniques discussed in other articles. Whatever medium you choose, you must remember that even the smallest detail may be picked up during the mold making process. So it is important to have as smooth as a surface as possible. Clay Sculpture Sculpting in clay is probably the least expensive modeling technique, net to carving plaster. It can be done without investing too much money on tools. There are many types of clays that can be sculpted. If you are not a sculptor, you may want to start out by trying a polymer clay, such as Super Sculpey. Polymer clay has become a very big industry and there is alot of useful information available in books and magazines. You can also probably find classes at your local arts and craft stores or art association. There are many modeling tools and texture sheets available to help you as well. To use clay, simply take it out of the package and "condition it". Conditioning it basically means softening it up a bit so you can form it. You can do this by hand or by using a clay machine that is the same as a  pasta machine. Then make it into your desired shape. Viola, you've got a master. Another type of clay that is also readily available in modeling clay. Modeling clay is usually oil-based and does not harden. This works well with many molding and casting resins because it will not stick and doesn't require the use of release agents. Most modeling clays are also non-toxic. They are used in very much the same way as polymer clay, except for the fact that there is no baking or hardening. If you plan on making a your mold out of silicone rubber, you can use the actual clay models. However, if you want a thermoformed (vacuum formed) mold, you will need to make replicas in a different material which can withstand heat and can will not deform. For example, you may want to make plaster replicas of your model. Plaster, Wood, Foam, and Wax Carving Carving is another hand method of creating a master prototype. It is also pretty easy to find carving materials and tools. Basic tools can be purchased inexpensively. However, if you are going to do this often, you may want to invest in a good set of tools, which can become quite expensive. You can carve out your model by hand in many different mediums. Wood, foam, plaster, and wax are the most readily available. There are also different types of printing blocks made out of lineolium that can be carved. Plaster is probably the most traditional medium used for carving models used in the production fo chocolate molds. It is inexpensive, relatively easy to work with, and can have a smooth finish. There are different types of plaster that can be used. Plaster of paris can be bought at any craft store. Other denser plasters, such as hydrocal, can be purchased online. Basically, mix the plaster and form it into a block by pouring it in to a container. Let it harden and then it can be carved. To carve wood, look for soft woods such as basswood. Many craft stores carry basswood and basswood cut outs. It is not expensive and is preferred because it carves easily and doesn't have large knots. You can also use different carvable foams and wax. Wax is the material many jewelers use to make their models before casting and is good for making silicone molds. One advantage of using wood or plaster is that you can vacuum form directly from your carving; whereas, you will have to reproduce your model if you use foam or wax. You can make silicone molds out of any of the materials. Some will need to primed to prevent the silicone from getting into the pores. One great way to carve is with a rotary tool. A rotary tool is a handheld power tool that has different bits that carve, engrave, cut, grind, round, rout, sand, and polish. Two major manufacturers are Dremel and Craftsman. Using a rotary tool, you can quickly carve out an object with alot of detail. With an optional flex shaft attachment, you can put the bits on a tool that is held like a pencil. This provides better control. Best of all, a rotary tool is not expensive and is available at most home hardware stores. |
|
|