Metal Casting | Refractories | Casting Metal

Casting is basically the manufacturing process through which a liquid material is emptied into a mold that includes a hollow opening of the desired art or shape and is then allowed to harden. This hardened casting is then removed and broken out in order to complete the process. Apart from using sand as the main mold material there is a metal that is used as the mold. Normally, a cast meehanite or an iron is used as the material for mold and the objects are made from the sand or metal. The cavity surface is basically covered with a thin layer of material that is heat resistant which can be either sodium silicate or clay.

Casting Molds: The casting molds are actually pre heated to nearly 392 degree Fahrenheit before the metal is pored in the cavity. The design of cavity for these casting molds does not chase the same principle for shrinkage like in the sand casting molds. This is because of the fact that the metal casting molds heat up and enlarge during the pouring process and so the cavity does not need to be expanded like in the sand castings. Nevertheless, care should be taken in order to ensure a correct thermal balance as you can use external water source for cooling or you can also opt for suitable radiation techniques.

Permanent Casting Molds: Although these permanent casting molds are not as flexible as the sand castings which allow to be used in different metal patterns or designs but these lower the cost of producing the part. When there is a production run of more than 1000 parts the permanent casting molds would produce much lower piece of cost part. Apart from this, the break even point also depends on the density of the part. There are more complex parts that are favored when you use these permanent casting molds. The typical part size would be around 50g to 70 kg and the basic materials used are medium and small parts that are made from magnesium, aluminum and brass and also their alloys.

Slush Casting Molds: The slush casting molds are actually a special type of permanent casting molds in which the molted metal is not allowed to solidify completely. After gaining the desired wall thickness the still not solidified molted metal is then poured out. This is basically used in order to make void ornamental objects like lamps, candlesticks and statues.

Corthias Casting Molds: This type casting molds is yet another variant of the permanent casting molds in which basically a plunger is used to pack the molted metal through the spure hole. This type of process allows thinner walls and to produce greater details.

Vacuum Permanent Casting Molds: This is also another type of permanent casting molds which is also similar to low pressure permanent casting molds. In this type vacuum is used rather than a pressure. You can make thin wall casting through this type of casting molds like in the other low pressure casting molds. Apart from this the results are high as there are no risers used.

Metal casting is an ancient technique that has a variety of applications and purposes. Civilizations from the dawn of time to present day have used metal working as a way of creating artistic, religious, and practical items. The process of metal casting involves melting metals at high temperatures and using molds to then shape the metal into new items. The furnaces used in metal casting helped pave the way for the Industrial Revolution, without which the course of history would be dramatically different. Metal casting is just one form of metal working that has seen a recent surge in popularity as resources are becoming more affordable and communities are springing up to share information, ideas, and projects.

Metal casting requires specialized equipment, knowledge, and some creativity. While metal casting is used on an Industrial level as the process cuts cost and proves to be highly efficient, many individuals participate in metal casting as a hobby and in artistic endeavors. Many people are drawn to metal casting for one reason or another, although there seems to be two main motivations that stand out. The first motivation that brings hobbyists to practice metal casting is need; people may need to create items or parts for other ventures. Metal casting is a great way to build hard to find pieces for models, restoration projects, and even just small replacement parts needed for common household items. The second motivation for using metal casting is using it as a way to create sculptures or other artistic endeavors.

Whatever the reason, small scale metal casting is attractive because that it can be done right at home, either in the backyard or workshop. Individuals working in metal casting are able to create home made tools and equipment like furnaces and molds. Metal casting is only limited by the individual’s desire, so for those with the time and the need, virtually anything is possible.

The actual casting process in metal casting has several forms, the most popular being sand casting. Sand casting involves creating a mold from sand which can be created at home, and then pouring the liquid metal into the mold. Afterwards, the metal is allowed to air dry and the mold is removed. This type of casting proves to be the most economical, but other types of casting can provide fuller detail and higher quality results.

Since metal casting involves working with metal in its molten form, the process can be dangerous if undertaken by the reckless or ill informed. The melting points of several metals are well above 1,000 degrees Fahrenheit, or 530 degrees Celsius. It is vital that anyone wanting to work with metal casting take all the proper precautions. Safety advice can range from simple  common sense such as “never look directly into a high powered flame” to more specific warnings such as “when molten metal contacts a nonporous surface with water it is liable to explode, splashing hot metal everywhere.” The use of appropriate safety gear such as gloves and goggles is necessary as well.

With time, dedication, and some know how, anyone can practice the craft of metal casting. Metal Casting is a very enjoyable and rewarding craft but it does require a certain amount of education to get started.

Metal casting is known and loved for the high temperatures, glowing molten metal, and the possibility to make nearly anything. Metal and their alloys are not the only things that can be used in casting. Casting in plastic, most notably resin casting, is becoming popular with artists and jewelers looking for something odd and unique.

Resin casting does not involve the use of furnaces, crucibles, or casting sand. In fact all one really needs for resin casting is a mold, some resin (of course), and time.

There are actually two forms of resin casting. The first kind is the one that more closely resembles metal casting, uses a mold and even gates and runners if it’s complex enough. The second type of resin casting is simply incasing an object in the resin. An example of this is using an ice cube tray and placing an object like a small pendant in one of the tray’s cavities and then filling it with the resin solution. After the resin dries you can pop it out of the tray. The pendant is now encased in hard plastic. This form is usually employed by jewelers and crafty moms but tends to be fun for everyone no matter age or experience. At the very least it’s a great way to get rid of some of the clutter around your house and disguise it as art. You can cast leaves, coins, and other objects in the resin to make anything from charms to magnets.

Resin casting using mold is generally used by those who work with models and miniatures. Resin casting is a great way to make several pieces at once so you can avoid shelling out money you may not have and waiting several weeks for delivery of your items. Who has that kind of time anymore?

Like metal casting, resin casting will require you to build a mold. If you are fortunate enough then you can easily find pre-made molds, especially if you are working with miniatures. If you don’t feel like buying these pre-made molds or just like doing things the hard way, then you will have to make the mold yourself. Don’t worry, it’s still fun.

You will need to find a molding box this will hold the rubber that will be used to make the actual mold until it dries. Many who work with smaller objects find that working with toy building blocks to create this molding block work extremely well and will provide added convenience. A wooden box will work as well, of course. The box, or flask, will not have a top or bottom, just the four walls. Place molding clay at the bottom of the flask and insert your original. Make sure to add a way for the resin plastic to enter the mold. This cup or funnel should be placed at the top of the mold. You are going to prepare the silicone rubber and catalyst which will be used to create the mold. Follow the instructions on the labels since each type will vary. A process called degassing can be used which will remove all the air bubbles from the rubber. This is a fun process involving a vacuum pump.

Slowly pour the rubber into the flask, covering the original. This can take up to a day to dry, so be patient. Remove the molding clay and repeat the process using the bottom part of the flask, or drag. You should have two parts now, with the original in the middle. When dry, remove the mold from the box and very carefully split the mold to remove the original.

Place the mold back together and prepare the resin solution, follow the instructions to the letter. Pour the resin into the top of the mold, where you placed the cup. The set time for the resin should be stated on the bottle, but for most it will take up to 30 minutes. When ready crack the mold open and remove the cast.

Resin casting can be a great family craft project but just make sure to follow all of the safety guidelines. This type of casting can still be dangerous even though you are not dealing with molten metals. Often times, the solutions and chemicals used in resin casting are poisonous if consumed. Not to mention that resin casting can be a bit smelly so working outside or in a well ventilated room is advisable.

Lost Wax Casting is an ancient technique that has been used to create very complicated metal castings and involved pieces that would other wise be impossible either because of economic reasons or manufacturing reasons. Everyone from small jewelers to large industrial foundries can use Lost Wax Casting. This process is also called Investment Casting when it is used in commercial industries. While jewelry makers are the primary ones to use the Lost Wax Casting, many others use it to achieve a number aims and goals.

Lost Wax Casting is the ideal and preferred method for artists who are interested in making items like sculptures or rings from a variety of alloys like bronze, steel, or copper. This process is quite involved but not all that complex as long as you have some kind of metal casting know-how. For anyone wanting to experiment with different casting methods Lost Wax Casting is a great option because it involves a few materials and methods that are not normally found in other methods like Sand Casting.

The most noticeable difference of Lost Wax Casting from other castings is exactly what’s in the name; the wax. To use Lost Wax Casting you do not necessarily have to be an artists but some skill in sculpting might be nice. You are going to start off by creating a sculpture from wax that will be the original.

You will then create a mold of the original. The mold is usually created from plaster with latex lining to help preserve the details of the original. If this is your first attempt at Lost Wax Casting you may want to make an original without a lot of detail just to get the feel for the entire process and so you do not become discouraged if something does not work out. Remember metal casting is a skill that must be learned by research, trial, and error. Chances are that you will not be completely successful, the first time around. The original piece is usually lost after the construction of the mold. This is normal and if you do want to prevent this from happening you can create the original from material other then wax like a metal alloy.

When the mold is ready you are then going to pour molten wax, you’re not ready for metal just yet, into the mold. The amount of wax needed for this step depends on the desired thickness. Once the copy is ready, you are going to remove it very carefully from the mold. You will remove any of the impurities from the copy. This is called chasing.

You will then sprue the copy. Spruing is the act of carefully placing paths that will let the molten metal in and air out. Afterwards, a ceramic shell is created around the copy. The shell isn’t really ceramic but a combination of liquid silica and sand. Traditionally, and in some areas still, animal dung and dirt is used to create the shell. The choice of which shell material you want to use is up to you. The shell is hardened in the kiln and the wax melts out. If you want to reuse the wax then collect it during this step. Wax can be reused a number of times and if you are on a budget or are just trying out different designs and methods, collecting the wax is encouraged. Once the wax is gone and all that remains is the hollow shell you will want to run water through it to make sure there are no leaks. If there are then you will need to patch them before pouring the molten metal.

You are going to want to reheat the shell before pouring the metal to avoid shattering the shell. The shell is still on the sprue tree so pouring the metal is an easy process. When the metal has hardened, then break the shell carefully and remove the cast. Afterwards, it is up to you to finish the piece to your liking and preference.

The Lost Wax Casting process is an enjoyable experience but it does use a few tools that you might need to purchase before hand, like the wax and spruing tree. At the very least, you might want to try Lost Wax Casting once or twice to get a feel for it. This way you have another casting process at your disposal.

Lost Foam Casting is a relatively new casting process compared to other metal casting procedures that date far back into antiquity. The first patent for Lost Foam Casting was made in 1958 but it was not until 1964 that what we know commonly as Lost Foam Casting was introduced.

Lost Foam Casting is a form of Investment Casting much like Lost Wax Casting. The key material of Lost Foam Casting is of course foam which is not used in other metal casting methods. The use of foam has many benefits to the artisan like ease of use and shaping and the relative inexpensive cost of the material. Each casting is going to be one of a kind since the original casting of foam is lost during the process.

The foam original will be replaced by the molten metal unlike the Lost Wax Casting where a wax mold is made of the original and then coated with a ceramic shell in preparation for the molten metal. Luckily, most foam is pretty inexpensive so the loss of the original shouldn’t pose a significant financial loss, just an annoying creative loss.

Foam is easily shaped by hand held tools but even still some practice may be needed to prefect the sculpting of the material. You will need to place a sprue into the foam which will allow the molten alloy to spread into the foam and adopt the shape of the item. Packing the foam and sprue in sand is a good way to insure that the mold will retain its shape through the pouring process. The metal will replace the foam by vaporizing it, and it is really quite a sight to behold.

Though there are many who prefer to adopt the procedures used in Lost Wax Casting for the Foam casting. After spruing the foam original you are going to dip it into a solution to create a shell and then pour the metal. The goal of this is to create a cleaner surface.

Whichever method you choose is really up to you. Many use Lost Foam Casting a quick and easy way to create something when visual appearance isn’t all that important. Many refer to Lost Foam as the “quick and dirty method”.

As for the type of foam to use you are going to want to steer clear of anything that will give off toxic fumes when heated.  Urethane foam is toxic. The popular foams to use are the polystyrene kind which is used to pack electronics and the polystyrene foam used for insulation. These foams can be found at many home improvement stores and even a few all purpose retail stores.

Lost Foam Casting is kind of like alchemy, transforming something inexpensive into something invaluable. Whenever you cast, make sure to take all proper safety precautions and wear safety gear. Always wear a long sleeve shirt, jeans, and the proper shoes. Don’t forget eye and face wear and of course gloves. Never forget that you are dealing with material that can very easily harm and disfigure or worse if not handled properly.

Many first time casters begin with Lost Foam Casting since it doesn’t involve mold making but if you are experienced and never attempted this method you will still want to be careful.

Many believe that iron casting is just simply out of reach for small furnaces but this is not the case. While alloys like aluminum are more prevalent in home foundries. Artists and hobbyists have also used brass, bronze, and even iron to fulfill their casting needs.

Industrial foundries commonly use iron for a variety of items like cookware, like cast iron pans, and even bridges. Casting iron provides an easy and effective method of making such large structural pieces and even smaller pieces for around the home.

The most common furnace type used by home foundries is the cupola furnace. The cupola is a basic furnace type that does not need a crucible as it allows the caster to pour the molten metal directly from the furnace into a ladle which is then poured into the mold. Cupola furnaces resemble smoke stacks and can be home made for those with enough confidence and some mechanical know-how to attempt it. The fuels used to heat the metal in a cupola furnace depend on the caster’s resources and preference. Many will use propane and some will use coal. There are a select few that will use waste material such as old scraps of metal and the powder at the bottom of bags of barbecue coal to fuel the cupola. For iron many would recommend the use of propane, but there have been some casters that have succeeded with waste material. Don’t be afraid to experiment with different fuel types to find the perfect fit for your furnace and need.

Finding a source of iron can be difficult and a trip to the scrap yard might be in order. This is just one of the exciting ventures that metal casting can provide you. After you locate your iron you will need to prepare your mold. This is assuming you have a pattern in mind that you want to cast. If not, then go ahead and figure something out even if it’s a small piece in order to test your iron casting ability. Since sand casting is the most popular casting method you might want to use it for the iron casting especially if you are familiar with the method and not with iron.

After making the sand mold and placing the runner for the molten iron you will melt the metal. The melting point of iron is 2,800 degrees Fahrenheit or about 1538 degree Celsius. Since all metals melt at different temperatures don’t be impatient if iron takes longer to melt and don’t be surprised if it’s quicker.

When the molten iron is ready you are going to pour some into a ladle and the pour that into the sand mold. The sand mold is held in place by the cope and drag, which is the top and bottom part of the mold. The runners are in place in the mold to allow the molten iron a place to enter. When the iron is cool, remove the cast from the sand carefully and there you have a cast of iron.

As with all metal casts, you will need to follow the appropriate safety steps to avoid any accidents. Accidents with molten metal will always be very painful so make sure you wear gloves, jeans, boots, and a long sleeve shirt. You may also want a heavy duty leather apron and a pair of goggles.

Iron casting is a great way to create restoration items or pieces for around the home and even for artistic purposes.

Metal Casting presents a great opportunity for artists and hobbyist as it gives them a certain amount of control and creative license with regards to the end result. Metal Casting is an ancient practice that is still used to this day in industries such as manufacturing airplane components to small scale hobby casting.

The casting process which is so crucial to the entire form is where one takes melted metal and creates an object based on a pattern by using a mold. On first glance the entire casting process seems complicated and even convoluted but with a little patience and time, most of which will be spent reading, the process involved in metal casting can be understood and even mastered.

Metal casting does take technical know how and skill. Luckily, you do not have to be born with a golden furnace to cast. This means that if you have the will, not to mention the mold and the furnace and all the other tools, you have the way.

Since each casting method differs slightly from the other, it is advised to read up on it before you try your hand at the technique. The most common casting method is sand casting which is probably the best way to start out a metal casting career. What I will attempt to do is to provide a general overview of the basics in metal casting. The specifics for each casting process will differ of course since, for example, Investment casting uses wax and not sand and die casting uses centrifugal force where most other casting processes do not. So, it will be important to research the process involved with each individual casting type but it is always great to have a base to build from.

The casting process for most forms will include making the pattern, making the core, if one is needed, molding and the actual melting of the metal, pouring, and then finishing it all off by cleaning.

Pattern making is the first step in any casting process. You will have to first determine what is needed for your project. The pattern is considered the original and can be any needed shape from a bolt to a figure of a horse. If the object being made is hallow or has parts with holes or other empty spaces, you will need to make a core. The core is inserted into the mold so that the casting can take the appropriate shape and that metal does not fill in areas that should be left empty. The core is collapsible so it can be removed after the casting process without any damage to the finished product.

The molding contains the flask which is created by an upper half or the cope and the lower half which is the drag. In the sand casting process, sand is packed into the molding where the pattern is placed. Once the sand is rammed or packed the pattern is removed then preparations can be made for pouring.

Depending upon the kind of metal and the type of furnace the melting step will vary. The Crucible is what the metal is melted in and the Crucible handling tools will allow you to safely move the crucible to the mold where you will pour the molten metal. You will allow the metal to solidify, and then remove the mold very carefully.

During cleaning you will be removing any excess bits and pieces on the finished product and in essence, make it nice and clean, and ready for whatever intended purpose you had in mind.

The casting process is a lengthy one involving many steps, beyond the general ones stated here. For this purpose it will be important for you to do some reading and some research so that your attempts at casting will come out just as you would like.

Metal Casting is more than just an excuse to play with molten metal it is actually a great way to create art and complicated pieces of machinery or other items that would otherwise be nearly impossible to make. Metal Casting is really a great way to save money…while playing with molten metal.

The reason that Metal Casting has survived the test of time is a matter or efficiency. Some of the earliest casting examples have been found in China dating back thousands and thousands of years. In fact every major civilization from the Egyptians to the Romans practiced metal casting. This skill came back into vogue during the Renaissance and has continued to advance and evolve from there. While Sand Casting is the most popular casting process there are many, many more processes available to the backyard foundries.

Not everyone is going to be casting heavy pieces like engine parts or cast their own motorcycles. So for those that just want to make decorative pieces you will not be using the same casting process as these heavy duty casters.  For artists creating small scale statues or embellishes and for hobbyists that need a decorative touch to their model plane or boat might want to consider using gravity casting for their needs.

Gravity casting seems to be especially useful when dealing with aluminum and other light alloys. The basic idea behind this casting process is pretty much exactly what the name suggests. The metal is introduced into the mold by the force of gravity. Most other casting process either use natural pressure difference like the kind in certain sand casting procedures or they use forced pressure like in centrifugal casting to get the molten metal into the mold.

One of the most common uses for gravity casting is when permanent molds are going to be used. Also called a die, the permanent mold is really only economical for those planning on using the same mold numerous times and will need to keep the quality at a constant level. While some temporary molds can be repeatedly used the quality of the finished product will begin to suffer over time. With die molds the quality will remain the same. Die molds should be seen as an investment. Yes, they will be more costly then other molds; however they will outlast cheaper options for molds. With Permanent molds, they are created using cast iron, steel, and other metals.

Gravity casting is used for the permanent mold process with pleasing results. Gravity casting is usually used when the finished product is more visually based then structurally based which is why this method is a favorite of artists and even some jewelers. The loss of strength is due to the lack of pressure used in this process. For those that need the strength but still want to use gravity casting, more of the molten metal will need to be used which will increase the weight.

Relying on gravity will take patience, although it will be needed for larger products.

If you have never tried gravity casting then you should, because you just may be surprised by what such a simple thing like gravity can create. For the sake of humor, make an apple and see what happens.

The Do It Yourself movement is certainly not a new one. The term, DIY was popularized in the 1950s but the concept has been around for ages. The concept behind DIY is undertaking a variety of projects either home improvement, restoration, or arts and craft without the help of paid professionals.

Recently the DIY movement has received a boost of popularity with the aid of the internet. Many are finding that DIY projects are easier to undertake with the help of instructional websites which provide step by step instructions and real advice from people who have actually accomplished the DIY process. Several of these sites provide ideas, photos, message boards, and a sense of community for Do It Yourselfers that was simply not available years ago.

DIY projects can include any number or projects and ideas. Certainly the most common projects include home improvement such as cabinetry or installing plumbing fixtures, but one of the oldest DIY projects has to be metal casting.

The DIY casting movement has been around ever since metal casting itself has been around, which is quite some time. Metal casting is the act of taking molten metal and shaping it with the use of molds into something new. Metal casting has been used in the ancient world for the use of making weapons, jewelry, and even religious icons. Today, DIY metal casting is used to create parts and items for use in a variety of hobbies and restoration projects. This includes home improvement items as well. Metal casting can be used to make door knobs, cabinet handles, and other such items. For hobbyists, small model parts and miniatures can be created. Even artists use metal casting for sculptures and jewelry creation.

Metal casting possesses the true spirit of Do It Yourself. Many metal casters are drawn to the skill because it provides a cheap alternative to purchasing items or having commercial foundries make custom items. Nearly everything used in metal casting can be made by the caster. The furnace, molds, tools, and many others are made by most casters.

Like other DIY projects, the DIY casting movement is being helped along my communities that are found online. These communities act as meeting grounds for casters to share and exchange knowledge and ideas, not to mention blueprints for furnaces and ingredients for casting materials.

Metal casting is the pinnacle of DIY projects as it involves the fabrication of items from metal. After creating a mold of the desired item the caster will melt down iron, brass, or aluminum in a furnace. The molten alloy is poured into the mold and allowed to cool. The cast is removed to reveal a copy of the original pattern. There are several casting methods so undertaking a DIY casting project can be very involved and addicting.

In the spirit of DIY, metal casters strive to make the best for the least. A great source for aluminum is soda cans and many casters gladly travel to scrap yards for iron or brass.

The DIY casting movement is really gaining steam as many realize how cheap and fun this alternative is.

The most noticeable item in any backyard foundry is the furnace. This is no surprise really, because without the furnace the entire metal casting operation would be nonexistent. The furnace can take really any size and form depending upon the need and budget of the metal caster. What really makes home metal casting furnaces really unique is how many of them come into creation.

Sure there are plenty of companies that will gladly sell furnaces for the hobby metal caster and while this can be a viable solution to your furnace needs many metal casters prefer another method.

Making your own furnace is not as far fetched as it may seem and if you already a Do It Yourselfer, chances are you will have the needed skills and tools in your workshop or garage already. There are a variety of reasons why people make their own furnaces. The most common reason is fulfilling a need.

Many hobbyist and metal workers find out, to their dismay, that the local commercial foundries can not make the needed part or if they do, they feel the need to charge an outrageous sum. Not to mention the fact that the traditional methods of metal casting is quickly becoming forgotten as the industry turns to electric furnaces. So many hobbyists find that constructing their own furnace is an absolute necessity and a great way to preserve a piece of craftsman history. The artisans who use metal casting to create sculptures and other pieces find that making their own furnace grants them a greater amount of control over the entire process. This is actually how many people get into metal casting to begin with.

Most likely, your first furnace is going to be a small and rather simple one. There is really no need to run before you can walk when it comes to something that will be using intense heat and melting iron which can be rather dangerous.

Home made furnaces have been constructed from coffee cans to trash cans or sheet metal welded together. While there are a few components that really should be bought like the retractor to line the furnace walls which should be resistant to high temperature for a prolonged period of time along with special connectors and regulators, most of the furnace can be created in your own home. You should be able to find most of the components that you can not make at hardware stores or plumbing supply stores for relatively cheap.

Along with the furnace parts you will also need to buy a crucible which will hold the metal as it melts along with the appropriate tools that you will use to handle the crucible. While you are at it you might as well buy all the safety equipment like gloves, protective eye wear, and leather shoes. There is other safety equipment that you will need depending on the type of work and the type of furnace you are going to make.

Most likely, your first furnace is going to be a simple cupola variation. The cupola furnace which is going to resemble a smoke stack is a simple design and is relatively easy to make for anyone with mild craft skill. This type of furnace will not require a crucible since you will be able to pour the molten metal from the furnace itself into a ladle that can then be poured into the mold.

DIY casting furnaces are a great way to connect yourself with your metal casting work giving you more control. While building the furnace can be complicated at first, once you delve into it you will find the experience enjoyable and fascinating.