Back to: BASIC TECHNOLOGY JSS3
Welcome to class!
In today’s class, we will be talking about metalwork project. Enjoy the class!
Metalwork Project – Methods of Joining Tools and Materials Used
Metalwork project involves the use of metal sheets to fabricate articles.
Fabrication
It is the use of metal sheets to make different metal articles for use.
Fabrication processes
1. Sketching: This is the art of drawing the desired article, with dimensions on paper first.
2. Measurement: On the metal sheet, the size of the article to be fabricated must be measured next, using a scriber.
3. Marking out: At this stage, the scriber is used to mark-out parts of the article on the metal sheet.
4. Cutting: A snip is used at this stage to cut through the path marked on the metal sheet.
5. Filing: To smoothen the rough edges of the cut article, a pedestal grinder or file can be used to achieve this.
Tools for metalwork fabrication
(i) Measuring tool: The basic measuring tools used in metalwork include centre square, steel rule, outside and inside callipers and protractor. These tools are all used for measuring lengths, widths and angles.
(ii) Marking-out tool: The main tool used here is the scriber. This tool is used together with measuring tools.
(iii) Cutting tools: The list in this category, include chisels, snips, bench shears and hack saw. One must consider the thickness of the metal you are about to cut before choosing the right cutting tool.
(iv) Files: In metalwork projects, files are used to remove sharp and rough edges to produce a smooth final finish.
(v) Drill bits: Drill bits are fitted into the chuck of drilling machines. They are used to bore holes on metal plates. They come in different types which include countersunk, flat, straight-fluted, twist and combination drill bits.
Shape development
(i) Bending: Most metalwork project involves bending and folding, either cylindrically or as square-box shape. This changes the shape of the metal.
(ii) Drawing down: This is the process of stretching a metal by hammering.
(iii) Twisting: This is a beautification process in forging operation.
(iv) Upsetting: This is the process of increasing the thickness of metal. It is useful in processing bolt heads.
Metal finishing
Metal finishing is the process of beautifying metal surfaces to prevent rust and prolong its economic life.
Types of metal finishing
- Buffing: This is the method of using wheels covered with soft cloth or leather to polish the surface of the metal.
- Lacquering: This is the application of the lacquer to the metal surface to prevent corrosion.
- Enamelling: This is the application of corrosion-resistant material, like plastics, on metal to make the surface glossy and hard. E.g. kerosene stoves.
- Scratching: This is the use of a thin metal piece and steel brush for cleaning metal parts thoroughly to be finished.
- Painting/Spraying: This is the application of oil paint to metal for coating purpose.
- Copper finishing: This is the oxidation of copper surface to form shades of different colours like purple, red, brown, etc.
- Spot Finishing: This is the forming of pressed spots on metal by the use of ornamental finishing and abrasive powder and oil spread over the metal.
NOTE: Spot is achieved by placing the metal over a spinning wood on a drill chuck.
- Electroplating: This is the protective coating of a metal with other metal such as tin, zinc or chromium to prevent corrosion.
In our next class, we will be talking about METALWORK PROJECTS – METAL JOINING. We hope you enjoyed the class.
Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.
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