Lesson Notes By Weeks and Term - Junior Secondary 3

TERM – 3^RD TERM

WEEK THREE

Class: Junior Secondary School 3

Age: 14 years

Duration: 40 minutes of 5 periods each

Date:

Subject: BASIC TECHNOLOGY

Topic: PROCESSING OF WOOD II

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Define wood conversion
2. Identify the stages of wood conversion
3. Define wood seasoning
4. Identify the types of wood seasoning

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

PROCESSING OF WOOD II

Conversion

Wood conversion is the process of transforming raw timber into various forms suitable for specific applications. It involves several stages:

1. Log Selection: High-quality timber starts with selecting suitable logs based on species, size, and intended use. This ensures the desired properties in the final product.
2. Debarking: The outer bark of the logs is removed, revealing the wood underneath. This is often done to reduce contamination and make subsequent processing more efficient.
3. Sawing: Logs are cut into smaller sections or boards using saws. This step determines the dimensions and shapes of the final wood products, such as planks, boards, or beams.
4. Grading: Wood is sorted into different grades based on quality, appearance, and structural characteristics. This helps match the right wood to its intended use, ensuring efficiency and structural integrity.
5. Planing and Shaping: The surfaces of the wood may be planed to achieve a smooth finish, and additional shaping may occur to create specific profiles or contours required for the final product.
6. Joinery: In some cases, pieces of wood are joined together using various techniques like mortise and tenon joints, dovetails, or gluing. This enhances the structural stability and aesthetic appeal of the final product.
7. Finishing: Wood may undergo surface treatments such as staining, varnishing, or painting for protection, preservation, and aesthetic purposes.
8. Drying: Green or freshly cut wood contains a high moisture content. Drying, or seasoning, is essential to reduce moisture and prevent issues like warping or cracking.

Seasoning

Wood seasoning, also known as drying or curing, is a crucial process to reduce the moisture content in wood, enhancing its stability, durability, and usability. The primary goal of wood seasoning is to bring down the moisture content of freshly cut wood. Green or unseasoned wood has a high moisture content, which can lead to issues like warping, splitting, and decay if used in construction or manufacturing without proper drying.

Types of seasoning

1. Natural Air Drying: One common method of seasoning is air drying, where lumber is stacked in a way that allows air to circulate around the wood. This process can take several months to years, depending on the wood species, thickness, and environmental conditions. Air drying is a traditional and cost-effective method used in many small-scale operations.
2. Kiln Drying: To expedite the drying process, wood can be placed in a kiln, which is a controlled environment for drying. Kiln drying involves regulating temperature, humidity, and airflow to achieve faster and more uniform drying. This method is commonly used in commercial settings and results in wood with reduced moisture content in a shorter time.

EVALUATION: 1. Define wood seasoning

2. Mention and explain the types of wood seasoning
3. Discuss the stages of wood conversion.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively