What You Need for Mold Making and Casting

Posted by EnvironMolds , Labels: , , , , Friday, July 22, 2022 2:16 AM

Making molds and casts involves a range of materials, supplies and equipment. Following is a look at the different items that should be kept at hand before beginning a mold making or casting project.

Mold making and casting are intricate arts that require different materials, supplies, tools and equipment. A lot of details are involved in these processes and it calls for careful and precise usage of the procedures as well.

To begin with, there is a choice of a variety of materials like clay, wax, plaster, alginate, liquid latex rubber, silicone rubber, polyurethane resins and more. The selection depends on the technique, artist’s dexterity and preference. The common tools and supplies range from brushes, spatulas, gloves and containers to knives, rasps, scalpels, pliers, calipers, etc. In case the materials involve an element of risk to the artist, it is advisable to wear protective equipment like gloves, goggles, mask and coat. Some even use a respirator to prevent inhalation.
 
The mold making usually starts with a mold box and a base plate. The master model is either placed in the mold container or secured to the base with clay or a suitable adhesive. A sealant may be required if the model has holes or happens to be porous. Applying a thin coat of an appropriate release agent is usually recommended as it will help in easy demolding.

Again, depending on the mold making material, it may have to be degassed using a vibrating table, pressure pot or vacuum chamber with pump. This will eliminate air pockets in the material which show up as unsightly bubbles in the mold.

Once the mold has cured properly, the demolding process can involve cutting the mold with a sharp knife, scalpel or using other tools to extract the model from the mold. The mold is smoothened using certain specific tools before it is ready for casting.

In case the mold is made in two or more parts, it will require placing keys that facilitate an easy coming together of the mold parts. If the mold is very flexible, it may even have to be reinforced with a shell mold that is generally made with plater bandages.

The casting process usually begins with applying a release agent on all the surfaces of the mold to ensure easy demolding later. The material may also have to be degassed before pouring into the mold. Once the cast has cured, it is extracted using tools and finished as required.

The cast can even be painted to create the desired effect. Some rubbers and resins require special paints and dyes as the regular ones are not compatible with these materials.

Last but not the least; all the materials, supplies and other requirements – like say, latex rubber, silicone rubber, scalpel, mixer and vacuum chamber – should always be sourced from a established and reliable source to ensure that everything is of top quality and will work as expected. This will ensure best results in the mold making and casting.

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The Various Facets of Sodium Silicate

Posted by EnvironMolds , Labels: , , , , Wednesday, July 13, 2022 4:24 AM

The compound sodium silicate has many applications. While industry folks are familiar with sand molded metal castings, artists prefer to use it to deflocculate clay slip and create antique finishes on ceramics.

Sodium silicate is a simple inorganic sodium salt that is also called water glass. It comes in a flaked solid or powdered form which is dissolved in water to make an alkaline solution.

This silicate lends itself well to a host of uses that are quite varied in nature. Consider this – sodium silicate is equally effective in both treatment of waste water and preservation of foods. It is used in paper and detergents as well.

The same formula can also be used to reduce porosity in concrete, stucco and plaster. Applying a thin coat on masonry surfaces after they have cured will seal the surface, thus minimizing water penetration. In fact, sodium silicate displays excellent physical and chemical properties that are useful in bonding and coating applications. It will dry to form a tough, tightly adhering inorganic bond for metals, ceramics, glass, etc.

Apart from this, sodium silicate works as a deflocculant for clay slips and can also render an instant antique finish on ceramic surfaces.

But the most common and useful application is in metal or foundry mold making applications. A blend of sand and sodium silicate is used to make the mold. the mixture is packed into a core box of the desired shape and wires or rods are inserted as required for support. This is exposed to carbondioxide gas from a low pressure source or esters which induces a chemical reaction that will solidify the core. Once it has solidified, it is ready for use.

These molds are used in the iron, steel and cast iron industry. Molten metal is poured in the sand molds to make the casts.


Where to buy?


EnvironMolds is a veritable powerhouse supplier in the world of arts and crafts. The website is packed with a broad range of materials, supplies, tools and equipment for making molds, casts and life casts. All products are from leading brands with top quality, reasonable prices and environment safety being the differentiating factor across the board.

The repository includes sodium silicate from the inhouse brand of Artmolds. This inorganic multipurpose additive is formulated in aqueous form and can be used for different purposes. It is low cost, odorless, non-toxic, moisture-resistant and non-flammable too. As it is made from sand and alkali, it proves to be ecologically harmless in fresh water environments too.

However, it can irritate or burn the skin and eyes on contact. Observe safety precautions like wearing splash-proof goggles, rubber gloves and coveralls.

The company further advises that the product should be stored in a cool, dry, well-ventilated area, removed from oxidizing agents, acids, active metals, heat or ignition sources and foodstuffs. It should be protected from physical damage and sealed properly when not in use. If properly stored, unopened containers can be good indefinitely.

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The Molding and Casting Approach to Making Replicas

Posted by EnvironMolds , Labels: , , , , Friday, July 1, 2022 1:43 AM

Mold making and casting together form an efficient process for reproducing almost anything. There are clear differences between the two techniques and artists should know the ins and outs of both.

The most common method of making an exact three-dimensional replica of an object is molding and casting. In fact, most of the everyday items that people use in their homes and offices have undergone the molding and casting process.

Mold making


The mold forms the first step of making the replica. This is a hollow cavity of the shape of the model or master that is to be reproduced. It is also considered as a negative of the desired object.

Molds can be made with different materials and there are various techniques for the same. While anything like clay, wax, resin, silicone rubber, polyurethane rubber or thermoset mold rubber will lend itself well for making molds, the general consensus is that molds should be made with flexible materials as this makes it easier to demold the cast.

When working on molds, the mold making material has to be mixed properly and may even require a vacuum pump with vacuum chamber to ensure that it is free of air bubbles.

The best part about molds is that most of them are reusable and can be used for making multiple casts. But keep in mind that while some molds lose their shape quickly and are good for single castings only, others will also have a limited shelf life and will start to deteriorate with time.


Casting


While the mold is the first stage, casting forms the final stage that delivers the finished replica of the original model. A casting is usually made by pouring the casting material into the hollow mold. It is allowed to cure and then extracted to obtain the final product. This can be sanded, painted or finished as desired.

Here again, there are different techniques for casting and varied materials lend themselves well for the casting process. Yet, in general, it is better to use materials that cure to a hard form as this ensures efficiency in the process and durability in the final cast. The materials that are commonly used are plaster, gypsum, concrete and polyurethane resins apart from an assortment of rubbers. A vacuum chamber may again be required – especially for rubbers – to ensure that the cast is smooth and blemish free.

As the casting is the finished product, it obviously cannot be used in the process again and again. However, at times, casts are used to make secondary molds as they already hold the desired shape.

In sum, mold making and casting are used in conjunction to make duplicates of varied items. The have their own inherent characteristics and artists have to familiarize themselves with all the features before attempting to use them. These processes can also be used for other purposes like mask making and doll reborning. Life casting also draws on this to make reproductions of the live human body!

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