Casting Part 1: Choosing the Technique for Your Project

From left to right:  A hot glue skull with foil backing, a plain hot glue skull and a plaster cast. All made from the same mold.

A  good starting point for any newbie haunter or prop maker would be casting. I’m not talking about the professional latex or vacuum mold; I’m talking about an easy way to replicate an object with items often found in your home.

When deciding on making a cast, a few things must be considered: How heavy you want the final product to be, how much mess you are willing to make, how sturdy you need the prop to be and what type of environment the prop will be in.

After mulling over those considerations, below are two types of mold making techniques I use and the pros and cons for each.

Plaster of Paris is great for statues, columns, stones, and anything that you don’t mind having quite a bit of weight to. You can put paint colors directly into the mix before pouring and plaster paints well. The cost of a 50 – 75 pound bag usually runs about 15 dollars and can make a plethora of castings.

On the downside, because of the weight, it doesn’t work as well for body parts within a lighter framed prop (like PVC). It can be brittle if not mixed correctly, takes about eight to twenty-four hours to dry and can be pretty messy to work with.

Although several experts have proclaimed plaster doesn’t last when not sealed, I have quite a number of outdoor plaster props that haven’t disintegrated after seven years of exposure to the elements.

Hot Glue is great for making a translucent mold that is light, a little flexible and takes to paint well. You can basically make a mold with hot glue with objects the size of a beach ball or smaller. I haven’t attempted anything larger because the bigger the object the more glue sticks are needed.

The hot glue replica can be used in itself or as a mold that can potentially make several casts of an identical object. An example of making replicas with hot glue is pictured below.

From left to right top: The start of a duct tape skull and next to it is a painted glue skull. Both made from the same mold. On the bottom is a molded bone made from a hardening mix.

If you are planning on making it a casting mold rather than just a replica of an object, you may want to use a heavy duty hot glue gun. It will deliver a thicker stream of hot glue and make a thicker, stronger mold.

The small hot glue gun can be used for smaller object replications or for molds that need only a few castings.

Whether you are using a large glue gun or small, the best part about making a mold with a hot glue gun is immediacy. Within 15 minutes of completing your replication, you can handle it, paint it, and cast in it.

Another intriguing idea that has caught my eye is duct tape body casting. I plan to try it this summer. A few tutorials can be found at Costume Dork, where he uses duct tape as a mold and at Art-Rageous Art Ed Resources, which uses the tape for just replication.

If you would like to learn casting techniques using latex or other professional materials, try Monster Makers which offers tutorials, types of molding products and more.

Part Two of Casting Techniques will have the actually step-by-step directions and techniques of how to work with hot glue and plaster. Look for it later this week.

If you have any unusual ways of making molds or castings, please feel free to share.

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