Molding and Casting Terms

Molding and Casting Terms

This page is a good starting point if some of the words we use are new to you.

Go to these pages for more specific information:

Glossary of Terms

A thickening agent used for paints, resins and pastes. Used with Pros-aid to blend edges of foam latex appliances. Particles are extremely dangerous to inhale.

The final piece taken from mold. A POSITIVE. Usually made from Casting plaster, Hydrostone, foam latex, slip latex, UltraCAL 30 or other material. Cast can generally be used to describe the entire process, for example: The do a body cast the artist would prep the model, make a mold and take a cast from the mold.

Very much like Plaster of Paris except that it has a slower setting time. Forms a skin when used in a mold. Used for finished casts. No good for latex molds or foam latex. Paints well. 2,400 psi..

Synthetic substitute for Foam Latex. Two part system that cures in a matter of only a few minutes instead of hours. Not as flexible as "Hot Foam" but much easier to use. Gram scale is generally required.

Two cooking pots that fit into each other. Water is usually put in the bottom pot which slowly transfers heat to the upper pot into which you place your material. Used to melt wax and other materials that are delicate or dangerous when exposed to direct heat. Personally I prefer to use peanut oil in the bottom pot. Peanut oil won't evaporate out like water but it will expand so don't overfill. Peanut oil also has a much higher temperature range so it won't boil or give off fumes. WARNING: Don't be fooled, very hot peanut oil looks like cold peanut oil. Use of the stove with a double boiler and/or dangerous materials should be supervised by an adult. As in any laboratory setting, make sure you have a fire extinguisher present. Use of a candy thermometer is highly recommended.

Latex rubber based foam. Used in make-up prosthetic special effects for many years, the film Mrs. Doubtfire is a good example of skillful use of foam latex. Very flexible but won't survive rough handling or time very well. Requires gram scale, Mixmaster, oven, skill and experience. Mastery of foam latex is a minimum requirement of professional level makeup effects. Don't confuse Foam Latex with Liquid Latex, the two processes are different. We recommend and carry 4-part GM foam.

See Foam Latex.

See PVC.

Gypsum Cement. Hard and strong. Used in high quality art and novelty casting. Can't be worked with a template or formed by hand. Forms exceptional details. Very resistant to water absorption. 10,000 psi..

Liquid latex used for makeup effects like zombie skin, burns and scars. Usually has additives to protect the skin. Any latex which contains ammonia should not be used around the eyes. Overexposure to ammonia will cause blindness. This latex can be found makeup catalogs.

Liquid latex specifically designed for mold making. Usually can be thickly brushed on and won't shrink very much. Usually is thicker than other latex. Made from several different materials.

Liquid latex with "very high solids," which means it has much more latex than it has water. Used to "bulk up" or add body to other compounds. The Paste we sell has no ammonia and therefore is a favorite with people who like to use latex to "lay-in" beards, eyebrows and mustaches. Can be used as a mold compound.

Liquid latex used for Halloween type mask making. Is often thinner than other types of latex so that it can pick up details in the mold. It is used by filling the mold to the top and letting the plaster in the mold draw the moisture out of the latex. This will form a skin. When the skin is thick enough the "slip" is poured back into the container allowing the skin that remains to dry from both sides. It is important to use the proper kind of plaster for slip casting molds. Slip casting latex will shrink, so plan your sculpts accordingly. The fact that this type of latex does shrink helps it to remove itself from the mold. Budget projects can be brushed in.

MEDICAL ADHESIVE. A silicone based adhesive that works like super-glue. Used by professionals instead of spirit gum. Don't use it around the eyes. Don't try to use it without a good MEDICAL ADHESIVE REMOVER. Medical Adhesive in its present formula was discontinued in 1995. A new formula is pending.

AKA Pottery Plaster. Excellent for molds, especially for ceramics and slip latex (masks). Doesn't form a skin. Absorbs water very well after completely dry. 2,000 psi..

The same thing a doctor would use to put a cast on your arm. We use Gypsona Brand Bandages because they are very creamy and flexible. 2" and 6" are the most common sizes used.

PVC (Poly Vinyl Chloride). Simply put -- fish bait material. Also known as Hot Pour. Same material as the old "Creepy Crawlers" stuff. Very soft and rubbery plastic-like substance. Can be reclaimed by remelting. Melt in a double boiler and pour into your mold. Molds must be heat resistant as PVC melts at a very high temperature such as UltraCal 30 or Silicone. Comes in clear color but can be easily colored. Can be slush cast in some molds.

Something that is smeared, painted or sprayed over something else to keep it from sticking. For example petroleum jelly is smeared over the eyebrows to keep alginate from sticking to them. Releases are used for specific materials.

Gypsum Cement (looks and works like plaster). Excellent for foam latex molds because of its strength and resistance to heat. Standard of the industry for special effects make-up artists. 6,000 psi..