Jewelry casting is the process of pouring molten metal into molds. As a rule, it is called investment casting, because the mold is created from a wax model, which is then burned out, leaving behind an empty space inside the mold. This technology has been used for several thousand years and is still widely used by professional craftsmen and amateur artisans for making exact copies of jewelry and art objects. If you want to create jewelry with your own hands using casting, use the steps described in this article.
Silver casting technology
Silver casting in the factory is carried out using industrial technologies that require expensive equipment, significant energy consumption and the use of rare and dangerous components. Traditional millennia-proven technologies are more suitable for casting silver at home or in the workshop.
The most common of these are lost wax castings. The use of special wax for modeling as a model material is also popular. As a material for creating the form, gypsum or clay-sand mixtures are used.
Silver ingots for casting
Silver for casting can be purchased at Sberbank or at a jewelry store in the form of ingots. In this case, its composition is precisely known and knocked out as a sample. If you decide to use grandmother's spoons or scrap silver products - be prepared for the fact that you have to carry out an operation to clean the scrap from impurities. For example, silver is purified from impurities of base metals such as lead, copper and others by melting in a crucible with the addition of saltpeter, borax and soda. Nitrate binds base metals, oxidizing them. Soda and borax transfer these oxides into solution, forming liquid slag. Silver remains at the bottom of the crucible in the form of an ingot.
Lost wax casting. This silver casting technology is the most accessible for beginners to master. The model is made of a material whose melting point is lower than that of a molten melt. Around the model is filled or molded form of gypsum or sand-clay mixture.
Lost wax casting
The most common investment materials for wax are wax and paraffin. When the melt is poured into the mold, the model material melts and is forced out of the mold through a specially provided hole. The place of the model is gradually taken by silver. There is a variant of this method in which the wax model is burned out by heating the mold to a high temperature, and the silver for casting is poured into an already empty mold.
Mold Tools & Model Casting Tools
For casting precious metal products at home, you will need
- Crucible for melting or cleaning metal.
- Muffle furnace or gas burner.
- Steel tongs.
- Fireproof stand.
- Wax for modeling. Candle wax will not work.
- Molding compounds
- Mixing tank
- Scalpel, knives and files for processing the model and for finishing the finished product.
- Hammer for breaking flask.
- Protective gloves, goggles and apron.
- Fire extinguisher.
- Dremel (mini-drill)
- Vice, Crossbars and mandrels
On the manufacture of molds for casting silver is worth a little more. First, a model of the future product is created from wax by sculpting and cutting small parts with a scalpel, fully repeating its shape, but having a thin protrusion in the form of a round bar.
Silver wax model
This is a gate on which molten metal will fall into the mold. Next, the model is placed in the flask and the molding sand is poured.
If a dry molding sand mixture is used, then the vibration sealing method is used for molding. Next, the wax of the model is burned, and the mold is ready for pouring the melt.
Earth mold casting
Casting in the so-called earth molds is the oldest method, tested for millennia. Molding mixtures actually do not consist of black soil, but are a mixture of fine-grained quartz sand and plastic clay in certain proportions. For casting small products with a fine relief and a large number of parts, mixtures containing 12-15% clay are used, for large castings up to 25%. Gases generated during casting must flow freely through the walls of the mold.
Earth Casting Silver
The model for casting in earthen molds is made exactly repeating the original, but slightly larger in size. This is an allowance for shrinkage and subsequent processing of the product. Models are traditionally made of wood, wax and gypsum. Today, plastic models are becoming increasingly popular. Plastic holds its shape well and is easy to process.
Lost wax casting technology
Lost wax silver casting equipment is relatively simple and affordable for home use. The essence of the method lies in the fact that a model made of fusible material, when in contact with the liquid metal being poured, melts and is forced out of the mold through specially provided holes. The metal occupies the void formed in the place of the model and accurately repeats its spatial form.
It is necessary to fill the metal with a thin trickle to allow the material of the investment model to leave the mold, in order to prevent the formation of splashes of molten metal.
Silver casting at home
Important! Do-it-yourself casting of silver is a complex and fire hazardous process. Your workshop should have fireproof stands and fire extinguishers designed to extinguish electrical voltage. Be sure to use fireproof gloves, an apron, and glasses.
For casting silver at home, novice craftsmen usually choose the following technologies
- wax modeling
- earthen casting
- heating the crucible with a gas burner.
Of course, if you have a muffle furnace with adjustment and maintenance of the set temperature, a vibrating table and a centrifuge - your castings will only get better.
Casting silver at home is a complex, but quite feasible process with proper preparation and perseverance. I wish you success in mastering this branch of metallurgy!
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