2.1 Indicate the alloy metal that is specifically used to manufacture the following products and give TWO reasons why the metal is used: 2.1.1 Milk tanks 2.1.2 Fittings for hot-water copper pipes 2.1.3 Hammering tools that can be used in explosive atmospheres - NSC Agricultural Technology - Question 2 - 2018 - Paper 1

Brass is the alloy metal suitable for the fittings of hot-water copper pipes. Brass is selected for its strength and machinability, ensuring durability and ease of installation. It also boasts excellent wear resistance, hardness, and corrosion resistance.

The alloy metal used for hammering tools in explosive atmospheres is Bronze (specifically, Beryllium Copper). This metal is advantageous because it does not generate sparks during use, thereby reducing the risk of ignition in potentially hazardous environments. Additionally, it has low friction and is resistant to corrosion.

Annealing and Tempering are two hot-working processes that can alter the structural properties of brass. Annealing helps relieve internal stresses and improve ductility, while tempering enhances toughness.

Farmers might choose fibreglass troughs over concrete ones for two main reasons: 1. Lightweight — Fibreglass troughs are easier to move and install, making them more flexible on the farm. 2. Rust Resistance — Fibreglass does not corrode, ensuring a longer lifespan compared to concrete.

The resin used in fibreglass manufacturing is typically a low viscosity fluid that can be transformed into durable, tough solids. This transformation occurs when it is combined with a hardening agent, thus allowing fibreglass to maintain structural integrity.

Two methods to join fibreglass parts include using Pop rivets and Bolt and nut fasteners. Additionally, the use of fibreglass adhesive can also effectively bond the parts together.

Vesconite is preferred for various reasons: 1. It is ideal for marine applications due to its non-corrosive nature. 2. It does not swell or seize, maintaining operational integrity. 3. Its durability ensures it remains hard even under stress. 4. Vesconite exhibits low friction properties, enhancing performance. 5. It does not contain asbestos, making it safer for use.

To achieve sufficient cohesion when applying an adhesive, follow these steps: 1. Clean the surface properly to remove any dirt or contaminants. 2. If the surface is too slippery, sand it down to create a rough texture. 3. Apply a thin base coat if the surface is very porous. 4. Use a thin layer of adhesive, as a thick layer can lead to weak bonds. 5. Finally, ensure adhesive is applied to both surfaces for a stronger bond.

The procedure for testing the earth system of an electric fence includes: 1. First, short out the live fence line to ensure safety. 2. Then, switch on the energizer. 3. Measure the voltage between the GROUND and the Earth Spike using a voltmeter. 4. If the measured voltage is above 200 volts, the earth installation requires checks.

Electric fences can be used for farm security purposes and to create temporary fences for livestock management. They are also employed in fencing dangerous animals to prevent escapes.

Three alternative energy sources suitable for powering an electrical fence include: 1. Wind energy, which can be harnessed via turbines. 2. Solar energy, captured through solar panels. 3. Water energy, which can be utilized through hydropower systems.