a) Name the type of flame produced for each of the following oxy-acetylene gas conditions: • Excess acetylene • Excess oxygen • An equal balance between oxygen and acetylene - Leaving Cert Engineering - Question a - 2021

When excess oxygen is present, the flame produced is termed an Oxidizing flame. This flame is characterized by its bright, blue hue and is suitable for welding certain materials that require a high temperature without carbon contamination.

An equal balance between oxygen and acetylene creates a Neutral flame. This type of flame is typically preferred for most welding tasks because it provides a stable temperature and does not alter the chemical structure of the metals being joined.

1. Preparation of Surfaces: The surfaces to be joined must be perfectly clean and coated with flux. This ensures that there is no oxidation which would weaken the joint.

2. Applying Heat: A good flow of heat to the joint is essential. Before applying the solder, the joint must be brought to the temperature at which the solder melts, ensuring a strong bond.

A flux is required on the electrode during manual metal arc welding to protect the weld area and prevent oxidation. It forms a gaseous shield that keeps impurities away from the molten weld pool.

The welding earth clamp functions to complete the circuit during welding. It clamps onto the material being welded and connects to the electrode, ensuring proper current flow. This is crucial for maintaining a stable arc.

Slag forms on top of the weld, helping to pull impurities out of the weld. It provides a protective layer which prevents oxidation during the cooling phase of the weld, ensuring a better quality finish.

1. Always wear correct personal protective equipment (PPE) such as a face welding mask to protect against harmful rays and sparks.

2. Ensure that the area is free from flammable materials and that all electrical cables used are in good condition to prevent fire hazards.