VIDEO 3 Prinsip Pembuatan Jalur Las Downhand SMAW

Summary

This instructional video explains the principles and techniques involved in creating a welding bead (jalur las) using a 3.2mm electrode. The focus is on proper electrode ignition, maintaining a consistent distance (around 3mm), and controlling bead width for an even weld. The video also emphasizes the importance of safety through the use of proper personal protective equipment (PPE). Practical steps for welding, including maintaining a steady electrode movement and cleaning slag, are demonstrated. The session concludes with an invitation to explore creating wider welds in future lessons.

Takeaways

• 😀 Proper ignition of the electrode is essential, and it can be achieved through methods like sketching or typing (tapping and lifting the electrode).
• 😀 After ignition, holding the electrode steady for 3-7 seconds forms a spot on the workpiece, with a typical diameter of 5mm.
• 😀 Maintaining a consistent arc length (E&R) of about 3mm is crucial for stable welding and preventing defects.
• 😀 The width of the welding bead must remain uniform, following the principle of 'lebar sama maju' (consistent width and progress).
• 😀 To ensure consistent bead width, move the electrode steadily along the joint while keeping the arc length constant.
• 😀 Safety is a priority during welding; always wear full Personal Protective Equipment (PPE), including gloves, helmet, and protective clothing.
• 😀 Electrode preheating in an oven is essential for optimal performance before starting the weld.
• 😀 After completing a weld, remove slag from the surface by waiting for the weld to cool and then cleaning with a wire brush or chipping tool.
• 😀 The process of creating a welding bead involves two main principles: maintaining a steady arc length and achieving a uniform bead width.
• 😀 Consistency in the arc length and bead width ensures high-quality, smooth, and even welds with proper penetration.
• 😀 In future sessions, wide weld beads will be explored, which are useful for adding thickness to materials during welding.

Q & A

What is the primary objective of creating a welding seam (jalur las)?

The primary objective of creating a welding seam is to join materials together through controlled heat, while ensuring the consistency of the weld's width, height, and structural integrity. It involves maintaining the correct arc length and proper electrode technique to form a uniform seam.

What method is used to ignite the electrode in welding?

The electrode can be ignited using the 'sketching' method, where the electrode is lightly scraped against the workpiece and then lifted. Alternatively, the 'tapping' method can be used, where the electrode is briefly struck on the workpiece and then lifted.

What should be done after the electrode is ignited?

Once the electrode is ignited, it should be held for a few seconds. A 3-second hold will form a small spot, while a longer hold of 7 seconds will create a larger spot. This helps in forming the initial base of the weld.

Why is it important to maintain the correct arc length in welding?

Maintaining the correct arc length is crucial because it ensures the proper transfer of heat between the electrode and the workpiece, leading to consistent weld penetration and bead formation. A stable arc length prevents excessive spatter and poor weld quality.

What is the recommended arc length for this welding technique?

The recommended arc length is 3mm, which should be maintained throughout the welding process. This distance ensures the consistency of the welding arc and the appropriate amount of heat for the weld.

How should the welding seam width be controlled during the process?

The welding seam width should be controlled by maintaining a steady movement of the electrode. The goal is to ensure that the width remains uniform and consistent, and this can be achieved by moving the electrode steadily while keeping the arc length stable.

What is the significance of maintaining a consistent seam width during welding?

Maintaining a consistent seam width ensures that the weld has a uniform appearance and strength. It helps in avoiding defects such as weak points or excess material, which could compromise the joint's integrity.

What role does the electrode height (or arc length) play in weld formation?

The electrode height, or arc length, plays a critical role in ensuring consistent heat transfer to the workpiece. If the arc length is too long or too short, it can lead to poor weld quality, including weak or uneven seams.

What safety precautions should be taken before starting a welding session?

Before starting a welding session, it is essential to wear full Personal Protective Equipment (PPE), including a welding helmet, gloves, and protective clothing. This ensures safety from sparks, UV radiation, and other hazards associated with welding.

Why is it important to wait for the workpiece to cool before cleaning off the slag?

It is important to wait for the workpiece to cool until the red glow disappears before cleaning off the slag. Cleaning the slag while the metal is still red can result in the slag sticking to the surface and potentially damaging the weld's structure.