Metal Casting Zone Info Blog

Kent Kelin asked:


Brass casting, as the name suggests, involves the use of brass as the molten metal. Brass casting can be carried out by the way of sand casting only. Sand casting can be defined as a ‘cast part’ produced by formation of a mold from a mixture of sand and pouring the casting liquid (mostly molten metal) into mold. Then the air-cooling of the mold takes place. After the solidification of metal, the removal of mold takes place. The metal used here is brass. It is a known fact that brass is an alloy of copper and zinc. Hence, to be precise, the molten metal consists of two elements.

Sand molding consists of two types- ‘Green sand’ molding and ‘air set’ molding. The first one consists of a blend of moisture, clay, silica sand and other additives. The second one makes use of dry sand bonded to all the above materials except moist clay, by the way of using an adhesive, which is fast curing.

At times, there is a placing of a temporary plug (in the mold cavity) to enable the formation of a channel to pour the fluid which is to be molded. The molds of the second type, i.e. the air-set molds result in the formation of a 2-part mold. The two parts are bottom and top. The tamping-down of the sand mixture takes place as it gets added. Many a times, the final assembly of the mold is vibrated to get the sand compacted and get the unwanted voids filled. Then the molten alloy (brass) gets poured into mold. After the solidification and cooling of brass, the separation of casting from sand mold takes place. Normally, such molds are one-time usable.

Patterns: A designer or an engineer provides the design of the object to be produced. On the basis of this design, a pattern is built by an efficient pattern maker by the use of plastic, metal, or wood. Polystyrene can also be used. The casting brass would get contracted during solidification. Non-uniformity can also result out of this. Therefore, the size of the pattern should be a bit larger as compared to the final product. ‘Contraction Allowance’ is the name given to this difference. Brass enters the mold cavity through a runner system including sprue and other feeders.

Molding box: A molding box having multiple parts (also known as casting flask whose bottom and top halves are called drag and cope respectively) is constructed for receiving the pattern. There may be an addition of sand to nullify the defects introduced due to the pattern getting removed.

Chills: To have a proper control over metallurgical structure and solidification of brass, plates of brass, or any other metal can be placed in mold. A hard structure may get formed at these places. Chills can be used for promoting directional solidification as well.

Design Requirements: The thing in making and the pattern corresponding to it should be designed in such a way that every stage of process can get accommodated. One should be able to take away the pattern without causing any disturbance to molding sand.

Hobby Metal Casting

Kent Kelin asked:


 
Brass is a great metal to cast with as it can provide some really great looking results.  Many believe that brass, an alloy of zinc and copper, has been around since our prehistoric ancestors. Today brass is used for a multitude of products from coins to trumpets not to mention a whole bunch of other musical instruments. The low melting point makes brass a really great material for metal casting since even the smaller home grown furnaces can be used. By adding and subtracting alloys from bronze one can successfully make hard or soft bronzes. Aluminum and tin are sometimes added to bronze to create a layer that is not corrosive and very durable. Of course, for the home foundry users, playing alchemist isn’t really an option or necessary and scrap brass is perfectly acceptable in many cases. Locating scrap pieces of brass should be sufficient enough for whatever project you have in mind. Due to brass’ gleam and yellow shine, many artists will use the alloy for sculptures, jewelry, and other decorative items. Other metal casters may choose to use brass for general hardware needs or vintage car restoration, and of course, whatever else they may choose. Generally there are three casting methods that prove to be suitable for brass casting. Metal casters may choose to experiment with different methods and should not allow themselves to be limited. Lost Wax casting is usually associated with bronze casting but can also be used for brass and for really any other metal. By using a wax model and covering it with a ceramic shell, artisans are able to inject the molten alloy which replaces the wax. Chipping away the shell will reveal the brass piece. Lost wax casting is used when a high attention to detail is needed. Artists or metal casters looking to create decorative brass pieces or sculptures will find that the lost wax casting technique will meet their needs far better than other techniques and methods. Die casting is yet another method used for brass casting. Die casting is normally used in commercial foundries since the initial start up cost is undesirable for the smaller home foundries. By using a reusable mold created from steel, the caster will be able to create scores of identical products. Die casting with brass should be used if the caster or artists is planning to make multiples of one product and can find a viable market for those pieces. Sand casting is probably the oldest type of casting and is still a popular method especially for small foundries. The brass is poured into sand molds and can create a unique look which may be preferred for the artisans. Sand casting tends to be the most economically sensible for small foundries and if the casting does not have to be incredibly attractive then this method is preferable for many. Whichever casting method is used for casting the brass really depends on the individual. Many find that casting brass to be fun and easy since it does melt rather easily. A large expensive furnace is not a requirement when casting brass so first timers using small home made furnaces will find this alloy attractive. Many have even been able to melt brass in small ceramic pots using charcoal! Some ideas of what to make with brass include candle holders, plumbing fixtures, and even musical instruments.

Metal Casting

Enigma-lite asked:


It is made of cast brass or bronze and is about 2″ high. there is a loop at the top, as though for a cord.

On one side is a seated figure with long hair with his left arm resting on a shield and his right arm holding a stick. there is a letter at each corner. E at the top, I bottom left and T bottom right. the word “ROMA” is written on the bottom.
On the other side is a figure standing on a ball. It has long hair and holds a round object to its body with the left arm. the right arm seems to have the fist pressed agaisnt the object. the letters “RM” are at the bottom left and the number 1750 on the bottom right.

I think it came from a Phillipino lady.

The object I such a mystery to me I don’t even know what kind of person to ask. Is it religious or possibly masonic? is it a weight? Is it a momento? Please can somebody help?

Brass Metal Casting