In relation to metalworking, casting is the process where metal is liquefied and poured into a mold which is then cooled and solidified into the shape of the mold’s cavity. The solidified piece of metal also referred to as the casting or ingot is then released from the mold to complete the process. There are different types of casting methods including; hand pouring, sand casting, investment casting, lost wax, spin and centrifugal casting.
The casting process has been used for thousands of years for making sculpture, jewelry, tools and more. Here at PMC Supplies, we specialize in offering tools for both melting down precious and non-precious metals and pouring them into a mold. We carry graphite, steel, and cast iron molds to mention a few. These molds are offered in a variety of shapes and sizes to accommodate your specific needs. We also carry a full line of melting furnaces, crucibles and torches for the initial melting process as well as handling tools and safety gear for handling your metals during the casting process. Whether you are out mining for your own gold, have scrap jewelry you want to melt down or simply practice metalworking as a hobby, we have the tools you need to cast your metals from start to finish!
Metal casting can be a lucrative hobby when dealing with precious metals. With the proper tools and equipment you can begin melting down your own gold, silver and copper materials into bars or other forms for resale. We also carry all the necessary accessories and chemicals in order to refine your precious metals to an even more purified state, allowing you to get top dollar for your material.
Metals can be melted using a torch, an electric, propane, induction furnace or even a microwave melting furnace. Determining which method is best for you will depend on your budget, the type of material you are melting and the amount of material you wish to melt at one time.
First, metal is heated until it reaches a molten state. This is done so by using a crucible to hold your material and a heat source such as a melting furnace or a hand torch for melting. The metal is heated in a crucible to its specific melting point and then is poured into the mold of your choice to complete the process. * Be sure to pre-heat your graphite ingot molds to prevent thermo-shock and cracking.
An inexpensive casting method where a sand and clay mixture is used as the vessel in which to pour your molten metal. The sand/clay mixture is often contained in a metal, wood or wax flask or mold in order to be able to compact the material to a dense state for optimal pouring results. Because of its malleable texture, sand casting can be used to replicate intricate objects by pressing the object into the sand to leave a negative impression of the design that is then filled with your molten metal. You can also carve patterns or designs directly into the compacted sand. The mold is filled with the molten material which will then cool and harden. Once the metal has solidified, the mold can be hammered in order to crack the sand and expose the metal object.
Investment casting is one of the oldest casting methods where molten metal is poured into a ceramic mold. The mold is first formed to your specific design by creating a disposable wax pattern. The wax design is then completely surrounded or “invested” into a ceramic slurry which eventually solidifies into the mold. The term “lost wax casting” is used because the original wax design or pattern is melted out of the mold after the object has been formed. Lost wax casting is not the most efficient method if you wish to create multiples of the same design as each time a wax pattern is made; it is completely consumed during the process.
This casting method can be used with aluminum, bronze, cast iron, steel and magnesium alloys and is best for casting metals with intricate detail or complex designs for automotive, military and aerospace industries. This casting method will require molten metal, a metal die, wax, ceramic slurry, furnace and a machine for grinding, cutting or blasting.
Spin casting or centrifugal rubber mold casting is a method where a rubber mold is produced from using centrifugal force. Molten material is poured into a cavity through a small opening at the top of a disc shaped mold and the material is pushed against the cavity’s inner walls as the centrifuge moves at a specific speed. The mold is filled with the material and continues to spin as the metal or plastic begins to solidify inside the hollow container. Spin casting is a commonly used non-expendable method for casting products that have great detail and surface finish such as fishing lures and tackle components, belt buckles, trophies, souvenirs, pins and medallions.
Use the below list of suggested products to help you choose the right products for your application. Keep in mind these are only suggestions and there are many different variables to take into consideration when choosing the right products for your melting needs.
We offer a variety of Melting Furnaces and choosing the right one will depend on how much material you are looking to process at one time, the area where you plan on doing most of your melting, your budget and of course your experience level.
This melting furnace is great for beginners, or people who are on the go since it is small enough to take with you on your prospecting travels, and those who are looking to process small amount of scrap jewelry, gold flakes or other material.
This melting furnace is great for melters with some prior experience and who are looking to process larger amounts of material at a time. This kiln will need to be used outdoors or in a well ventilated space.
These units are great for melters on a commercial or hobbyist level of experience. This easy to operate machine can be used indoors and comes with a crucible and pair of tongs with each Unit.
You will need some sort of heat resistant vessel to liquify your material in during the melting process. Graphite and ceramic are both commonly used materials for crucibles because of their extremely high melting points. Crucibles come in a variety of sizes, shapes and materials. Choosing the right crucible will also depend on variables such as; the type of material you are melting, the amount of material you will be melting at one time, and your melting process (whether you are using a torch method or using a melting furnace of some sort). Below are links to some of the different style crucibles we offer.
This style crucible is great for those who are using a torch method to melt their material. This crucible should be seasoned before using it to ensure your best results.
We offer a variety of graphite crucibles that can be used with our different melting furnaces. Graphite crucibles are commonly used inside our Propane, Kwik Kiln and Digital Melting furnaces. We offer replacement sizes for each specific unit. Some units can handle multiple size variations depending on how big the batch of material is you are looking to melt. These medium and high density crucibles are recommended for using when melting any precious materials.
You will need some type of mold to pour your melted material into in order to create a loaf, bar, brick or coin. These molds come in a variety of shapes and sizes ranging from 1 gram cavities all the way up to 1,000 oz. molds. We carry molds in a variety of materials including graphite, cast iron, and steel.
Graphite is an ideal material for metal casting as it can withstand extremely high temperatures. Metals will release with ease and you will not require the use of a releasing agent or lubricating spray. Graphite molds can also be engraved and personalized to your liking. We offer custom engraved and custom shaped graphite ingot molds upon request. Graphite molds will start to deteriorate over time and after repeated use. Most customers find they can use a graphite mold between 30 - 60 pours before they need to be replaced. *The exact number of uses will vary. Excellent for pouring gold and silver.
Steel molds are also a great option and offer durability and longevity. Steel molds will last much longer than graphite but they do require a releasing agent or lubricating spray to be used before each pour to prevent the material from sticking to the mold. Our steel molds are offered in adjustable versions as well as wire strip molds. Our adjustable molds form your metal into a suitable shape for using in a rolling mill for further flattening.
Cast iron molds are suitable for melting processes that do not require a smooth finish and are more commonly used for non-precious metals such as copper and brass. These molds are durable and will last many pours, but you will need to use a releasing agent or spray to lubricate your mold before pouring otherwise your metal can stick to the inner cavity of the mold.
You will need a heat resistant stirring stick to stir your molten material during the melting process. They also can be used to help skim and remove impurities from the surface of your melt. These rods come in a variety of heat resistant materials including graphite, glass, and ceramic as well as a variety of sizes depending on your needs. We also sell our uniquely designed 2 sided “Gold Finger” stirring rod and ladle which is great for skimming and removing impurities from your material because of its design.
You will need some sort of heat resistant surface to act as a landing for all of your tools, pouring molds, and your crucibles. These items will be EXTREMELY hot during your melting process and will need a safe place to rest when not in use. Some furnaces are also recommended to sit on a heat resistant surface if they are not designed with a sufficient heat resistant barrier. We recommend that the Kwik Kiln and any of the propane style furnaces be placed on a heat resistant surface as a precaution. Heat Resistant boards come in a variety of sizes and materials, each with their own specific heat capacity. These are also perfect surfaces for all of your soldering needs!
You will need several types of safety gear in order to conduct your process safely, especially when working with such extreme temperatures. We recommend having a good pair of heat resistant gloves, a heat resistant apron, heat resistant sleeves, heat resistant mask/face shield, heat resistant goggles and in some cases a respirator for added safety.
You will most likely need some sort of casting Flux during your melting process. We sell several types of flux including Anhydrous Borax, Boric Acid and Hank Chapman’s Flux. Flux is used for deoxidizing, seasoning crucibles, keeping your material liquified, and more!
We highly recommend doing research and educating yourself before beginning a casting or refining project. There are many crucial steps, processes and safety measures you will need to be familiar with before successfully carrying out your project. If you are brand new to casting, or are somewhat experienced but are looking to expand your knowledge base, we offer a number of books that specialize in casting and refining. For beginners we recommend the “How to Smelt Your Gold and Silver” by Hank Chapman Jr. This book covers all basic topics regarding casting and refining your material including safety equipment, fluxes, heat sources, and more. It is written in simple to follow language and even includes a full glossary of commonly used terms and their definitions! For more advanced metallurgists we recommend one of our more advanced books such as “Brown’s Assaying” or “The Recovering and Refining of Precious Metals” book.
You may want to invest in a digital scale of some sort to weigh your scrap, and material. We offer a variety of sizes from small portable “pocket” scales to larger tabletop size scales.
After you have melted and/or refined your material, you may want to test its purity. We offer testing acids, testing needles, digital testers and special magnets to do just that. You can use methods such as the “Scratch Method”, a digital reading or even a “Magnet Test” to determine the purity of your material.
We also have carefully designed a variety of all inclusive melting kits that have everything you need to start melting your materials today! These kits are available with both electric and propane style furnaces and come with a variety of accessories, tools and safety equipment to take the hassle out of selecting them individually, and for an even better value!