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Lost Wax Casting Lost wax casting basics. Remember that when you make something out of wax, it could take many hours and you only have one chance to cast it. If you are incorrect at any stage, the whole piece will be ruined and all that work will be lost. (maybe that is why they call it lost wax casting) When you use a natural item, if it is unsuccessful, it is easier to get another critter than to try to resurrect your art creation. My suggestion is to practice on a couple of bought wax pieces that you do not have too much time invested in and get the procedure down before risking casting your time saturated piece. This is a brief synopsis of Lost Wax Casting to familiarize you with the procedure. Essentially, Lost Wax Casting involves the following procedure: 1. Make figure out of wax exactly how you want it to look like when it is finished. There is no need to take into consideration relief angles. 2. Weigh item. If made from wax, multiply the weight of the wax by 11 and add 15 grams for the sprue base and put this much silver aside. 3. Sprue wax item onto wax wire to make a path for the molten silver to follow. 4. Fill with investment, once sprue base is attached to the flask, (investment is a pourous clay based compound similar to plaster of paris formulated to let air flow through the compound when the silver is introduced) 5. This needs to be vacuumed or vibrated to get out as many air bubbles as possible. Some times a debubblizer will help. 6. The burn out starts after the investment sets up. The burnout time varies with the type of wax or material used for the initial item. It could take from 5 to 12 hours depending. Slowly turn the temp up to about 1300 degrees and keep it there for 1 hour and bring the temp down to 900 degrees. 7. This next step involves either a vacuum casting machine or a centrifugal casting machine.( I favor the centrifugal casting machine). 8. Place the pre-weighed amount of sterling silver into the crucible and place the flask in the cradle. Using either a oxy-acetylene, or an air acetylene torch, melt the silver with a little flux until it moves freely. Then activate the centrifugal mechanism and voila! the metal should flow into the void made from burning out the wax pattern. 9. As soon as the centrifugal arm stops rotating, plunge the flask in a pail (use a metal pail for the obvious reasons) full of cool water. The superheated investment should boil off of the silver and give you your item attached to the sprue and base. 10. The procedure now is to cut off the sprue wires and to clean up the item and polish it. This is a rudimentary procedure for lost wax casting to familiarize you with the process, so the other tips might make sense.
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