Sand Casting
by Kerry Barlow

Sand casting is a simple and easy process to create detailed items in brass, bronze, steel, and aluminum. For the most basic and simple castings, ordinary beach sand may be used. This sand is mixed with motor oil to give it a consistancy that will bond together when it is packed down. Children do this all the time on the ocean using water to cause the sand to bond into sand castles. Oil is added to the sand just until the sand will stay together and hold its shape. A form is then used to hold the sand around the object being cast.This form may be a simple box of steel, or even wood. The form is made in 2 sections, a top and bottom half. Sand is poured into the bottom form to just cover the bottom and then the mold is placed into the lower form. A mold is made in the exact shape of the object you want to be cast. The mold may be made out of anything, glass, wood, plastic, another casting etc. A release agent is placed on the mold to prevent it from sticking to the sand. This is generally just a powder, the consistancy of flour.

Sand is then poured around the mold and tamped down until it is nice and firm. Two or more channels are cut into the sand,going from the mold to the openings in the form. These are used to pour in the molten metal. The sand is leveled off to the top of the lower form and more release agent is poured over the mold and the top of the sand in the lower form. The upper form is then placed over the lower form and more sand is poured in and packed tight around the mold. The sand is again tamped down to make it firm around the mold. The upper half of the form may then be removed from the lower half. The sand will stay in the upper half of the form and will have the shape of the mold. The mold itself may now be removed. If things were done correctly the mold will come free from the lower form easily.

The upper form may now be placed onto the lower form and the two halves are clamped together. The final step is the easiest, the molten metal is poured into the form thru the casting, or Sprue holes. When the casting has cooled, the form is opened, and the new casting may be removed. The sprues are cut off the edge of the casting and the sand may be reused. If all has gone well, you now have a new casting, ready to be painted or left in its original color.