Casting and Creating Modeling Work With EnvironMolds, LLC

A good thing about liquid latex rubber – apart from its flexibility and tenacity – is that it does not require a release agent. Indeed, a latex mold or cast will peel off easily on curing and generally does not require any release agent.

However, if the model used for making the latex mold is porous or brittle, a release agent is recommended. The preferred products for such applications are paste wax, thinned soap or a silicone spray. If using a watery soap mixture, it should be allowed to dry out before applying the latex.

Keep in mind that latex is soluble in petroleum based products. Petroleum jelly or other oil based compounds are a strict no-no unless you want the latex mold or cast to turn soft and mushy.

Many artists often use a thin mixture of castor oil and denatured alcohol (1:4) as an effective release agent when making latex molds or casts. It can be sprayed easily.

It is always better to test a release agent on an obscure area of the model or latex mold. Also ensure that the release agent does not leave any bubbles that can mar the final mold or cast.

EnvironMolds offers a wide range of mold making and casting materials and supplies such as liquid latex rubber, silicone rubber, polyurethanes, release agents and even mounts and name plates engraved for displaying the artworks.

Alginates are the mold making material of choice for life casting. This dental impression material is derived from seaweed and is completely safe for the skin.

The only drawback is that even after curing it stays soft and flexible. Therefore, it has to be reinforced with a mother mold that will enable it to hold its shape. Plaster bandages are commonly used for this purpose. Thin strips of plaster are rolled out, wetted and applied over the alginate. The plaster in the bandage dries quickly to form a firm and supportive shell mold.

However, the plaster itself may tend to peel back or curl away at times, especially on large surfaces. This will disengage the alginate and can distort the shape of the body mold.

We can overcome this problem by making locking keys before applying the plaster bandages. Place small acorns or clay molds with undercuts around the alginate mold while it is still mushy. Ensure that you completely cover these protrusions with plaster bandages as you work your way over the alginate. These ‘keys’ will lock the alginate and plaster molds together to form a hard body mold.

The plaster sets quickly and is demolded from the model before beginning the life casting process.
Keep in mind that at no point do you have to ‘unlock’ the two molds. They are used together during the casting.