Lesson Notes By Weeks and Term v4 - SHS 3

Lesson Video

This page supports the lesson note with a companion video and a short classroom-ready summary.

For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.

Performance objectives

• Describe the sand casting process and its importance.
• Identify the materials and tools used.
• Explain the steps involved in sand casting.
• Analyze the advantages and disadvantages of this process.

Lesson summary

Welcome, learners. Today, we delve into one of the oldest and most fundamental manufacturing processes known to humankind: Sand Casting. Imagine the heavy, cast-iron grinding bowl (*apotoyewa*) your grandmother uses, the engine block of a *tro-tro*, or the metal base of a corn mill. All these items are often made using sand casting. It is a versatile and cost-effective method for creating metal components of various shapes and sizes. By understanding this process, you will gain insight into how everyday metal objects are created, from simple household tools to complex industrial machine parts, right here in Ghana at places like the Tema Steelworks or the Suame Magazine in Kumasi.

Lesson notes

This section breaks down everything you need to know about the sand casting process. A. What is Sand Casting?

Sand casting is a metal forming process in which molten (liquid) metal is poured into a mould made from a mixture of sand, a binder (like clay), and water. The molten metal fills the cavity inside the sand mould, solidifies, and takes the shape of the cavity. Once the metal has cooled, the sand mould is broken away to reveal the finished metal part, which is called the casting. B. Key Terminology and Components

To understand the process, we must first know the language.

| Term | Definition and Explanation | | :--- | :--- | | Pattern | A replica or model of the object to be cast. It is used to create the cavity in the sand mould. Patterns are usually made from wood, metal, or plastic. They are made slightly larger than the final product to account for metal shrinkage during cooling. | | Mould | The complete sand block containing the cavity that the molten metal will be poured into. It is made of two main halves. | | Flask | A rigid frame, usually made of metal or wood, that holds the sand to form the mould. It consists of two parts. | | Cope | The top half of the flask and the sand mould. | | Drag | The bottom half of the flask and the sand mould. | | Parting Line | The surface where the cope and drag separate. | | Core | A separate part of the mould, made of specially prepared sand, placed inside the main mould cavity to create hollow sections or internal features in the final casting (e.g., the hole in the middle of a pulley wheel). | | Moulding Sand | A special mixture of silica sand, a binder (like bentonite clay), and water. This mixture must be strong enough to hold its shape but porous enough to allow gases to escape during pouring. | | Foundry | The workshop or factory where metal casting is performed. | C. The Gating System

Evaluation guide

• Explain the sand -casting process in manufacturing.
• Experi
• ential Learning: Show learners a video of an industry -based sand -casting process and let
• learners, in think -pair- share groups, summarise the casting process and present their results to