How to Make a Body Cast for a Wax Mold

Create a body cast with plaster.

Making a full-body cast is a fairly straightforward process; however, for those inexperienced in the process it could be dangerous. Plaster heats as it sets and the more plaster that you put on the model, the more heat she must endure. Plaster is the best way to get a mold that you will be able to use over and over again. Before you try to create a body cast for your wax mold, do some research on plaster casting.

Things You'll Need

• Plaster bandages (6 inches wide and 4 ½ yards long)
• Large bowl of water
• Thick rubber gloves
• 48 square feet of fiberglass mat
• 48 square feet of fiberglass cloth
• 3 gallons of fiberglass resin
• Medium size bowl (mixing bowl)
• Drop cloths
• 2 measuring cups
• Petroleum jelly
• 10 1-by-1-inch posts about 2 feet long
• 4 1-by-1-inch posts about 4 feet long

Instructions

1. Cover the area with the drop cloth. Cover the back half of the model with petroleum jelly. This will help the plaster release from the skin and hair of the model. It will work better if the model wears a spandex body suit and applies the petroleum jelly over the suit.

2. Cut the bandages into 2-foot sections to make application easier. Fold the bandage in half so you will have a 2-foot bandage that is 3 inches wide and double thickness. Carefully dip the bandage in the water once and use your fingers to gently remove excess water.

3. Apply the bandages in one layer, starting on the back side at the feet and moving upward. Depending on your model, you may have her lying on a table or standing up. Hold the top of the bandage with one hand and use the other to flatten the length against the model.

4. Apply the 2-foot posts to the model for the strength of the cast and to help the cast release from the model. Place one horizontally at the shoulder blades, the lower back and the ankles. Adhere them with additional pieces of plaster bandage. Apply a second layer of plaster bandages the same way as the first layer. Then using two 2-foot posts, make an "X" from the shoulder supports to the lower back supports. Use two 4-foot posts to make an "X" from the lower back support to the ankle support rod. Adhere them with plaster bandages to the model and to the other support rods.

5. If your model is standing, move to the front of the model and begin casting there. If your model is lying, allow to dry and remove the back cast to prepare for the front cast. Apply more petroleum jelly to the edges of the bandages where the front side will overlap. This will make sure that the front bandages will release from the back.

6. Grease the model again if needed, and apply the plaster bandages in the same way. Start at the feet, and make one solid layer.

7. Attach support rods at the chest, stomach and ankles. Apply a second layer of plaster bandages. Adhere the "X" supports from the ankles to the stomach, and the stomach to the chest. Adhere with more plaster bandages. You can use the bandages to "tie" the supports together; as they harden the structure is more secure.

8. Remove the hardened cast from the model by having her wiggle inside the cast. Remove the front first, then the back.

Fiberglassing the Mold

1. Cut the fiberglass mat and cloth into rectangles that will fit into the medium-size bowl. Put on the gloves and cover the inside of the cast with petroleum jelly.

2. Measure 8 oz. of fiberglass resin into the mixing bowl with one measuring cup and the hardener with the other. Mix the two for about a minute and place one piece of fiberglass cloth into the bowl. Remove any excess resin from the cloth and apply to the inside of the cast. Repeat this process, overlapping each piece of cloth by about a half an inch. Flatten the cloth against the mold to remove any air bubbles.

3. Repeat the process with the fiberglass mat once one half of the cast has been covered in fiberglass cloth. Only mix small amounts of resin at a time, as it will harden and become unusable. Allow to dry completely before attempting to remove the fiberglass from the plaster. Remove with care.

4. Trim away excess fiberglass and fit the halves together. You can use more of the fiberglass cloth to make the seams even and meet each other. Do not connect the two halves or you will not be able to remove the wax mold.

Tips & Warnings

• You can also construct this piece by piece, so the model would not be tired of standing or lying in one position for so long.

• You don't have to use fiberglass in the mold, this will just make a very sturdy mold. Wax can set up in plaster just as well.

• While working with fiberglass, you will need to wear a mask and preferably work outside.

• If the model is standing, have her slightly bend her knees. This will ensure she will not pass out during the casting.

References

• Studio Creations: Creating A Body Cast
• Sculpt: Get a Grip on Hand Casting
• BImmortal: The Body Casting Process
• Chicago-Mistress: Plaster Body Casting: Helpful Hints & Safety Guidelines

Resources

• FX Supply: How to Make Fake Body Parts
• Body Cast: Discover the Bodycast Arts