Sculpture And Casting

Step 1: Define a "shim." A shim is a thin piece of material used to fill small gaps or spaces between objects. In mold making, it is used to create a dividing wall.
Step 2: Understand its use in plaster mold making. When making a multi-part plaster mold directly on a model (e.g., a clay sculpture), thin pieces of metal called "metal shims" (or brass shims) are inserted into the clay to create a clean separation line. The first part of the plaster mold is poured up to this shim wall. The shims are then removed, a release agent is applied, and the second part of the mold is poured against the first, creating a perfect seam. This technique is specific to piece-molding in plaster.

Step 1: Evaluate the suitability of each material for mold making. Ice and Coal are clearly unsuitable materials for creating a stable, reusable mold. "Resin" is a very broad category; while some silicone resins are flexible, many epoxy or polyester resins are rigid.
Step 2: Identify the specific material. Korogel is a type of hydrogel known for its flexibility and is used in various applications, including mold making in certain contexts. Among the given choices, it is the most specific and correct answer for a flexible mold material.

Step 1: Define the terms in the context of Cire-perdue (lost-wax casting).

(A) Slip: This is a term for liquid clay used in ceramics, not typically in metal casting.
(B) Core vents: These are channels made through the core to allow gases to escape during the pouring of molten metal, preventing bubbles and defects.
(C) Sprue: This is the main channel through which molten metal is poured into the mold.
(D) Ducts: These are smaller channels that guide the metal from the sprue to various parts of the mold cavity.
(E) Claw: This is a type of chisel or sculpting tool, not a term for a part of the casting process itself.

Step 2: Identify the relevant terms. Core vents, sprues, and ducts are all essential components of the investment mold used in the lost-wax process. Therefore, (B), (C), and (D) are the correct terms.

Step 1: Logically sequence the steps of the lost-wax casting process (cire-perdue).

(C) Preparation of the core: First, a heat-resistant inner core (often clay-based) is made, roughly in the shape of the final sculpture.
(B) Modelling the wax form over the core: Next, a layer of wax is applied over the core and is sculpted into the final desired form of the sculpture.
(A) Application of the facing: A fine layer of investment material (facing) is applied to the wax model to capture all the fine details.
(E) Application of the negative mold investment material: The entire model is then covered in a thicker, coarser investment material to create the main mold. Sprues and vents are added.
(D) Melting and pouring the metals: The mold is heated to melt and drain out the wax (lost wax), and then molten metal is poured into the cavity left by the wax.

Step 2: Match the logical sequence to the given options. The correct order is (C), (B), (A), (E), (D). This matches option (1).

Step 1: Define a "piece mold." A piece mold is a mold made of multiple, interlocking sections. It is designed to be disassembled.
Step 2: Determine the purpose of this design. The primary reason for making a mold in pieces is to successfully cast an object that has complex shapes and undercuts. A one-piece mold would trap such an object. By designing the mold to come apart, the original model can be removed without damage, and the mold can be reassembled. This allows the mold to be used repeatedly to create multiple copies or productions of the same object. A "waste mold," by contrast, is destroyed after a single production.

Step 1: Define a "releasing agent." A releasing agent (or mold release) is a substance applied to the inside of a mold to prevent the casting material from sticking to it, thus facilitating easy removal.
Step 2: Evaluate the options as releasing agents.

(A) Polyester resin & (E) Resin: These are casting materials, not releasing agents. They are what you pour into the mold.
(B) Liquid detergent: A dilute solution of liquid soap is a common, simple releasing agent for plaster casting.
(C) Oil: Various oils (like petroleum jelly, mineral oil, or specialized mold release oils) are widely used as releasing agents.
(D) Slip: This is liquid clay used in ceramics, primarily for joining pieces or for decoration, not as a general mold release for other materials.

Step 3: Identify the correct agents. The true releasing agents on this list are (B) Liquid detergent and (C) Oil. Since no option contains only (B) and (C), there is an error in the question's choices.

Step 1: Understand the function of a flexible mold. Flexible molds are used to cast objects with complex shapes and undercuts, as the mold can be bent or peeled away from the cast object. Materials like latex, silicone, and gelatin are used for this.
Step 2: Evaluate the function of a Gel Coat. A Gel Coat is not the mold material itself. It is a specialized resin applied to the surface of a mold (typically a rigid mold, like fiberglass) before casting. It becomes the smooth, hard outer surface of the final cast object and is not flexible in the way a mold material is.

Step 1: Define a releasing agent. A releasing agent (or mold release) is a substance applied to a mold surface to prevent the casting material from sticking to it, thereby facilitating easy removal.
Step 2: Analyze the options. Liquid detergent, oils, and waxes are all common substances used to create a non-stick barrier. Alum (potassium aluminum sulfate) is a chemical compound used in various processes like water purification and as a mordant in dyeing, but it is not used as a mold release agent.