Casting Soap: Plaster Soap Stone

Here's a new way to hold your soap! Cast it into plaster! This block explores the interplay of two different materials - plaster and glycerin (aka soap!). Show voids in this plaster cast with cloudy, translucent soap. Use it just to experiment or put it next to your sink afterwards. Soap making just became a little more spatial.

First, you will need a few things:

- a sheet of ~1/8'' white foam core

- a sharp Xacto knife or box cutter

- a ruler

- a hot glue gun

- a box of Plaster of Paris

- a plastic container and two cups for measuring/mixing

- a wooden dowel or spoon

- a butter knife

- a box of glycerin (honey and olive oil glycerin will be cloudy and translucent. This experiment uses olive oil glycerin, but the honey one smells better. Probably best found at your local craft store, i.e. Michael's)

Step 1: Make Your Mold

1. Out of a sheet of 1/8'' foam core, cut out (5) pieces:

- (1) 1 3/4'' x 6 1/4'' base plate [a]

- (2) 3 1/8'' x 6 1/4'' sides [b]

- (2) 1 1/2'' x 3 1/8'' ends [c]

2. Glue together w/ hot glue gun:

- long side of [b] to corresponding length of [a]

- glue on the two [c] pieces

- glue on final [b] piece

**be sure to seal any cracks in the mold with hot glue to prevent leakage. Give special attention to bottom corners.

Step 2: Place Glycerin in Mold

**Before you start this step, if you want to make your soap perfumed or colored, check out this link to take it to the next level - https://www.instructables.com/id/Christmas-Soap/

1. Using a butter knife, cut triangular fragments and shavings off the glycerin block. Experiment with varying sizes and shapes. Pieces an be molded together to form larger shapes.

2. Place glycerin pieces into the mold.

- Experiment with bridging the sides of the mold with continuous pieces to let light into the plaster cast.

- The flat sides of the glycerin pieces should stick on the sides of the mold with a little applied pressure.

- Experiment with engaging all sides of the mold i.e. placing glycerin pieces flat on pieces [a],[b], and [c].

Step 3: Mix Plaster

1. Mix roughly 2 parts of plaster with 1 part of water (or until it looks like pancake batter!).

- Add a little more plaster to make the mix thicker, which works better with the glycerin.

Step 4: Pour Plaster

1. Pour the plaster in quick layers, giving yourself time to place a few more glycerin shards into the plaster.

2. Pour plaster ~1/8 below the mold's edge.

3. Let rest for 20-30 min, or until the plaster becomes warm from hardening.

Step 5: Remove From Mold

1. Carefully remove sides of the mold. Be sure not to press on the glycerin as it will dent or rub off.

2. Pieces of glycerin might come off with the sides. These can be pressed back into their place in the plaster.

Well done! Enjoy your soap via plaster!