Class: Senior Secondary School 1 (SSS 1)
Term: 3rd Term
Week: 11
Age: 15 years
Duration: 45 minutes
Subject: Carpentry And Joinery
Curriculum Theme: Entrepreneurship Trade Subjects
Previous Lesson: Qualities of a Good Joint.
Topic: ABRASIVES – Abrading Tools
Subject Matter: meaning of abrasives, types of abrading tools, grades of abrasives

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define abrasives.
List at least three types of abrading tools.
State the different grades of abrasives.

Affective Domain:

Appreciate the importance of using the correct abrading tool and abrasive grade for different tasks.
Show interest in the proper handling and storage of abrading tools.

Psychomotor Domain:

Identify various abrading tools by sight.
Differentiate between coarse, medium, and fine grades of sandpaper.

Participate actively in discussions about selecting appropriate abrasives.
Communicate effectively regarding the safe use of abrading tools.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Trade Subjects.
State Unified Scheme of Work for Carpentry and Joinery (SSS 1).
Carpentry and Joinery for Senior Secondary Schools by A.O. Ogunleye.
https://www.carpentrytools.com/abrasives
https://www.woodworkingbasics.org/abrasivetypes

Instructional Materials

The teacher will teach this lesson with the aid of:

Various grades of sandpaper (coarse, medium, fine).
Different types of files (flat, round, half-round).
Wood samples.
Safety goggles.
Charts showing different abrading tools.

Rationale for the Lesson

This lesson helps pupils understand how to prepare and finish wood surfaces properly. Knowing about abrasives and abrading tools enables pupils to achieve smooth finishes and improve the quality of their carpentry work, which is important for practical applications and entrepreneurship.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of woodworking tools and general workshop safety rules.

Lesson Content/Board Summary

ABRASIVES AND ABRADING TOOLS

Meaning of Abrasives

Abrasives are hard materials used to grind, rub, or polish other materials to remove unwanted parts or to achieve a smooth finish. They are used in carpentry to prepare wood surfaces for painting, varnishing, or joining.

Types of Abrading Tools

Abrading tools are instruments that use abrasive materials to shape, smooth, or polish surfaces. The following are types of abrading tools:

Sandpaper: This consists of abrasive grains glued to a paper or cloth backing. It is used for smoothing wood surfaces.
Files: These are hand tools with a series of cutting teeth used for shaping, smoothing, or removing small amounts of material from wood or metal. They come in various shapes like flat, round, and half-round.
Scrapers: These are tools with a sharp edge used to remove thin shavings from a surface, often to achieve a very smooth finish or remove old finishes.
Sharpening Stones: These are abrasive stones used for sharpening cutting tools like chisels, planes, and knives.

Grades of Abrasives

Abrasives are classified by their grit size, which determines how coarse or fine they are. The following are the common grades of abrasives:

Coarse Grade: These have large grit sizes (e.g., 40-60 grit). They are used for rapid removal of material, leveling rough surfaces, and initial shaping.
Medium Grade: These have intermediate grit sizes (e.g., 80-120 grit). They are used for general sanding, removing minor imperfections, and preparing surfaces after coarse sanding.
Fine Grade: These have small grit sizes (e.g., 150-220 grit and higher). They are used for final smoothing, achieving a very smooth finish, and preparing surfaces for painting or varnishing.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them what they use to make wood smooth after cutting or planing. The teacher then introduces the topic: Abrasives and Abrading Tools.
Pupils’ Activity: Pupils respond to the questions and listen attentively to the introduction.
Learning Point: Pupils are introduced to the lesson topic and relate it to practical experiences.

Step 2: Presentation of Abrasives

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher explains the meaning of abrasives, highlighting their role in smoothing and preparing surfaces in carpentry. The teacher uses examples like sandpaper.
Pupils’ Activity: Pupils listen, take notes, and ask questions for clarification.
Learning Point: Pupils understand the definition and purpose of abrasives.

Step 3: Types of Abrading Tools

Time: 10 minutes
Teaching Skill: Demonstration/Listing
Teacher’s Activity: The teacher presents various abrading tools such as different types of sandpaper, files, and scrapers. The teacher names each tool and briefly explains its function.
Pupils’ Activity: Pupils observe the tools, identify them, and note down their names and uses.
Learning Point: Pupils can identify and state the functions of different abrading tools.

Step 4: Demonstration of Tools

Time: 7 minutes
Teaching Skill: Practical Demonstration
Teacher’s Activity: The teacher demonstrates the correct way to use sandpaper on a piece of wood to achieve a smooth finish and shows how to use a file.
Pupils’ Activity: Pupils pay close attention to the teacher’s demonstration, observing the techniques for using the tools safely and effectively.
Learning Point: Pupils learn the practical application of abrading tools.

Step 5: Grades of Abrasives

Time: 6 minutes
Teaching Skill: Explanation/Classification
Teacher’s Activity: The teacher explains the concept of abrasive grades (coarse, medium, fine) and shows samples of sandpaper for each grade. The teacher explains when each grade is used.
Pupils’ Activity: Pupils examine the different grades of sandpaper and listen to the teacher’s explanation.
Learning Point: Pupils understand how abrasives are graded and their specific uses.

Step 6: Practical Identification

Time: 5 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher gives pupils different samples of sandpaper and asks them to identify their grades and suggest their appropriate uses.
Pupils’ Activity: Pupils physically examine the sandpaper samples, identify their grades, and explain their uses.
Learning Point: Pupils can practically differentiate between various abrasive grades.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define abrasives.
List three types of abrading tools.
Mention the three main grades of abrasives.
Explain the primary use of coarse-grade sandpaper.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the importance of selecting the right abrasive and tool for specific carpentry tasks. The teacher assigns homework: “Draw and label two abrading tools discussed in class.”
Pupils’ Activity: Pupils listen to the summary and copy the homework.
Learning Point: Pupils consolidate their learning and prepare for further study.

Lesson Keywords

Abrasives – Hard materials used for grinding, smoothing, or polishing.
Abrading Tools – Instruments used with abrasives to work on surfaces.
Sandpaper – A common abrasive material with grit attached to paper or cloth.
Files – Hand tools with cutting teeth used for shaping and smoothing.
Coarse – A grade of abrasive with large grit for fast material removal.
Medium – An intermediate grade of abrasive for general sanding.
Fine – A grade of abrasive with small grit for achieving smooth finishes.

Differentiation

For visual learners, the teacher will use charts and real samples of tools and abrasives. Kinesthetic learners will benefit from handling the sandpaper and tools during practical identification. Pupils who struggle will receive additional guidance and simpler questions, while advanced pupils can research and present on specialized abrading techniques or materials.

Note for teachers using this lesson plan

Ensure all safety precautions are strictly followed during demonstrations and practical activities involving tools. Encourage pupils to handle tools carefully and wear appropriate personal protective equipment, such as safety goggles, when necessary. Emphasize the practical application of the knowledge to real-world carpentry projects.