CHALK AND COLORED CHALK MAKING

Ingredients:

Acrosin

Mustard oil

Water

Plaster of Paris powder

Ultramarine blue dye

Materials:

Aluminum molds

Trays

Enameled mug or cup

Basins

Small boxes

Sawdust

Procedure:

1.      Clean and lubricate molds with acrosin and mustard oil for easy release of chalk.  (It is important to prepare molds ahead of time in order not to waste chalk mixture).

2.      Pour a measured amount of water into a basin, slowly adding Plaster of Paris powder. Mix until a thick solution is formed.  You may add a little amount of blue dye to water to break yellowish color of Plaster Paris powder. (Always add Plaster of Paris powder to the water; do not add water to powder).  This mixture will settle in 10 minutes in molds.

3.      Pour mixture into molds using a cup or mug and filling molds with mixture.  Chalk mixture must be poured into molds without creating air bubbles.

4.      Allow mixture to settle for at least 15 minutes before removing carefully from aluminum molds.

Drying and Packing:

1.      Sun-dry chalk sticks on trays for a day for sticks to harden.  Colored chalk sticks, however, must be dried in shade to preserve their color.

2.      Carefully pack dried chalk sticks in a small boxes with sawdust to avoid breakage.