Defines arc welding and write down the principle involved in establishing the arc.
Mention basic types of arc welding and give students work pieces of a given dimension with an electrode to weld a butt joint.
Consumable electrode arc overcalling,
Definition of arc welding
-maintenance of the arc.
-metal transfer across the arc.
Defines arc welding. students scratch the electrodes on the parent metal with draw it to a height arc length (1.5m) and maintains it at that length through out the weld.
Shielded metal arc welding (swam),
-principle of operation
(I) D.c transformer.
(iii)Flexible cable electrode.
Explain the principle of operation of (SMAW)
Show the SMAW equipment to students and ask them to put them into use in the workshop
-Using electrode connected to the electrode holder.
-connect the electrode holder to the feasible able which leads directly into the transformer. The D.C.
State the source of supply of the AC
-Explain how rectifier reduces the AC connect to the welding connect.
Striking the arc,
In order to establish an:-There are two methods which involves touching the electrode with the base metal and with drawing it to a length for the arc to be established scratching motion involves scratched the electrode on the parent metal in the motion the marches is being scratched.
Function of electrode coating
Classification of electrode
State that the flux coating prevents the weld from at mospheric contamination and for protective should on the weld.
Classify electrodes according to welding conditions.
Essential factors for maintaining high quality weld.
Teacher mentions the various types of rivet and state their uses and where they are important
State the advantage of rivet joints students should produce various rivet and drill mild steel plate to have a round hole the hammer them together to have a rivet joint by loud. Use also machine to loud machine rivet.
Basic sheet metal work hand tools and equipments.
Sheet metal work operation:-
Hand shares (snips)
Bench tools: stakes, Bick, iron, Hammer, Mattets etc.
-Grooved seam, paned down know up, ship on joint and ship in joint
Demonstrate the cutting of sheet metals using guillotine, use bending rollers to bend the sheet metal. Ask students to use universal jenny folding machine folding student should use hammer and mallets to beat the folded metals to shape for finishing.