The spiral playground slide shown is partially manufactured from stainless steel, and it is to be welded to the vertical stainless steel pole using tungsten inert gas (TIG) welding - Leaving Cert Engineering - Question 5 - 2019

1. TIG welding produces a strong, durable weld, which is essential for structural integrity, especially in playground equipment.
2. The shielding gas minimizes oxidation and contamination, resulting in a clean weld that is critical for stainless steel applications.

A rectifier is used in arc welding to convert alternating current (AC) into direct current (DC). This is crucial because DC provides a more stable and consistent arc, which leads to improved control over the welding process. This conversion helps in achieving higher quality welds by ensuring a reliable arc length and heat input.

Filling an acetylene cylinder is carried out under low pressure to prevent the risk of an explosion. The cylinder is generally filled until it reaches about 25 times its volume of acetylene. A porous material within the cylinder absorbs the gas, ensuring safe storage under lower pressure conditions. This method helps to prevent the gas from escaping too quickly or explosively.

Friction welding is a solid-state joining technique that generates heat through mechanical friction between two workpieces. The process involves rotating one workpiece against another under pressure. As the surfaces come into contact, the friction causes them to heat up, leading to a joining phase. A diagram would show two pieces with one rotating and the other stationary, applying force. This method is efficient and produces strong welds.

1. The bright light produced during MIG welding can cause eye damage. Proper eye protection, like welding helmets, should be used.
2. The fume generated from welding can be hazardous to health, necessitating proper ventilation to avoid inhalation.

In resistance spot welding, the electrodes are typically round and flat, allowing them to effectively apply localized pressure and electrical current to join overlapping metal sheets. On the other hand, resistance seam welding uses disc-shaped electrodes that rotate around the workpieces to produce a continuous weld along the seams.

In resistance spot welding, components are placed between the electrodes, and a pulse of electrical current is applied, generating heat that forms a spot weld. Conversely, resistance seam welding involves continuously passing the electrodes over the workpieces while applying pressure and current, creating a seamless weld along the joint.

Resistance spot welding is often used in the automotive industry for body panel assembly due to its efficiency and speed. Resistance seam welding, however, is suitable for applications requiring continuous welds, such as fuel tanks and domestic radiators.

Both welding processes require careful safety measures due to the electrical hazards involved. Spot welding requires monitoring to prevent overheating, while seam welding poses risks of burns and fume inhalation. Both methods necessitate the use of protective gear, proper training, and ensuring a well-ventilated workspace.