The Different Faces of Clay

 Clay is a multipurpose material that lends itself well for different uses. From sculpting and special effects to mold making, pottery and even other rudimentary applications – clay has a lot going for it.


Clay is a soft and malleable material that can be easily molded as needed. Kneading, squashing and shaping the clay into different forms is very easy and fun as well.

This humble clay is ready to use and very versatile - it can be used for different purposes in artworks. The most popular application is obviously for clay modeling – from making sculptures, masks and even prototype models to special effects and animation too. Moreover, the clay can be used as it is for making basic molds for casting resins, rubbers or even metals. It does not require any weighing or mixing before use.

Ceramic clay is commonly used to make pottery. The earthenware is fired in a kiln and glazed to make it hard and durable.

Apart from this, clay also proves to be handy for other minor jobs. For instance, if a model has holes or spaces, it can interfere with the mold making process. Clay can be used to plug these gaps or even tunnels that run through the model. Then the mold can be made as usual, but with a different mold making material other than clay.

In fact, clay is often the material of choice for making a containment field around the model when making the mold. The clay can be built to the height and thickness as required. Even when using other materials to make the mold box, clay is commonly used to seal the edges so that the mold making material does not seep out from the gaps. It can also be applied around the edge of the base to fill the gap between the model and the base.

Types of clay


The regular water based clay is suitable for children’s art classes and playrooms only as it tends to dry and shrink quickly. The professional grade oil-based clays are preferred by artists around the world. They have the same flexibility as regular clay, but the oil content keeps it from drying or cracking even after being exposed to air. They are firmer, capture fine details and can hold the form better as well. Heating and cooling allows the artist to control its malleability. In fact, this clay can be remolded and is inherently reusable.

Another variant of non drying and oil based modeling clays ballistic clay. This is primarily used by government agencies to test body armor as it is considered to be of similar density and elasticity as live animal muscle tissue.

EnvironMolds offers a range of oil-based clay options like Chavant Plasteline clay, Del Milano Plastilina clay and Roma Plastilina clay along with regular earthenware pottery and ballistic clays. Sulfur-free alternatives are also available as the sulfur content of regular clay can interfere with the curing of silicone and polyurethane rubbers. In addition, it also has a variety of tools for carving and sculpting during clay modeling.

Release Agent for Life Casting

 Mold making and casting requires the use of a release agent for proper demolding. MoldEZ Hair and Mold Release is used for the demolding of body molds and it proves handy for other functions too.


A mold maker or casting artist needs a lot of supplies and tools to make their art come alive. Apart from the regular items, there are a few tricks up their sleeve which ensure that the mold or cast turns out perfect.

 

For instance, the mold maker will deair the resins and rubbers in a pressure pot or vacuum chamber to ensure that the mold is bubble-free. Similarly, a casting artist will use specialized paints and dyes to color the resins and rubbers to eliminate the chances of cracking or chipping later on.

Another system that these artists follow is using a release agent before making the mold or cast. This is basically a lubricant which creates a slip effect and prevents the possibility of the material fusing to the model or mold. This in turn ensures easy demolding without any unnecessary stretching or tearing. It is basically akin to greasing a pan prior to baking so as to allow easy removal of the food without any sticking. This also fulfills a dual purpose as the release agent can seal the surface of porous materials.

Likewise, even life casting artists apply a mold release on the human body so that the body mold will come off easily without snagging in the fine body hair.

It follows that the type of release agent will have to vary depending on the usage. After all, a release that is suitable for metal may create an adverse reaction when applied on plastic and vice versa. This is why release agents are specially formulated for different materials so that they don’t impact the model or mold in any manner.

The life casting artist has to be particularly careful when working on the human body – specialized release agents like MoldEZ Hair and Mold Release or simple petroleum jelly works best!

Applying the release agent


Most release agents come in cans and can be sprayed or brushed on the surface to be molded or cast. Spraying is considered better as it will create a smooth finish. Brush marks can end up reproduced on the mold or cast and look quite unbecoming. Ensuring an even coat in the specified thickness is also essential.

MoldEZ Hair and Mold Release comes as a cream formulation that can be applied on the skin. It is usually preferred for the hair as the cream can be worked in easily and then combed to create a uniform effect. It will also wash out easily the first time itself. On the other hand, petroleum jelly can make the hair greasy and will not wash off easily either.

The same material also works well for filling in any pin holes in the body mold before proceeding to the casting stage. Some artists also apply this release agent on the edges of the alginate mold to bond it with the plaster shell mold.

What Makes MoldRite 25 The Best Silicone Mold Rubber

MoldRite 25 is a popular silicone rubber formulation suitable for general mold making. The molds are easy to make and turn out to be high quality and long-lasting. They reproduce perfect details too.

Silicone rubber is a versatile material that lends itself well for making different types of molds. Moreover, the rubber is also formulated in diverse forms to suit varied purposes – there are separate formulations for general molds, food molds, body molds, mask making and doll reborning and even for making quick molds.

MoldRite 25 Silicone is a standard silicone mold rubber for making traditional molds from the house of EnvironMolds. It is favored by mold makers, sculptors, prototype artists, craft artists and other artists for making molds of candles, soaps, toys, picture frames, figurines, statuary, jewelry, plaster moldings, architectural pieces, prototyping and more. In fact, it is suitable for reproducing any item which requires high quality molds.

This is a two-component tin-based silicone formulation with a 10 to 1 mix ratio by weight. It is mixed with cat-blue catalyst in the prescribed ratio which imparts a lovely blue tint to the mold. Both the rubber and catalyst should be weighed carefully and mixed in a clean container with a flat-ended spatula till a uniform color is achieved. The silicone mix needs to be deaired in a vacuum chamber prior to use. This will eliminate air bubbles that can otherwise tarnish the appearance of the mold.

MoldRite 25 is easy to pour and has a pot life of 2 hours and working time of 40 minutes. The common procedure is to first pour a print coat over the model before continuing with the mold making. It will capture perfect details right down to the smallest undercut or indentation on the model. A release agent is not needed as silicone does not stick to anything except itself. In fact, the tendency to stick to itself comes handy as multiple coats of the rubber can be applied where needed.

The rubber cures quickly to form a flexible and reusable mold. It should be allowed to cure for 16 to 24 hours before demolding and an additional 24 hours air curing before casting. Heat acceleration is not recommended. Full cure takes 3 to 7 days.

It is advisable to maintain normal temperature and humidity as higher temperature and humidity will decrease the work life and pot life with faster cure that in turn decreases the flow time too.

The finished mold has high tear strength, is durable and reusable as well. It can be used to cast different materials like clay, wax, gypsum, polyester resin, epoxy or polyurethane resin. Actually, any material can be used for making the cast except silicone rubber.

The molds can be used to reproduce any number of casts for years to come. Proper cleaning, drying and storage after dusting with talcum powder will extend the life of the rubber mold.


MoldRite 25 Silicone can easily be sourced online from the EnvironMolds website, https://www.artmolds.com. It is available in 1 pint, 1 gallon and 5 gallon kits.