How to Do Overhead Arc Welding
To do overhead arc welding, it is recommended to use bead welding in the overhead position.
Before moving on to the next bead, it is important to remove any rough parts of the bead and clean it.
For laying beads on .25″ or .5″ metal plate, the stick angle can be referred to in illustrations B and C.
To ensure good root penetration on the first bead, it is crucial to have a ninety-degree angle with the stick.
It is also important to use a welding rod that is suitable for the weld to maintain a short enough arc distance.
When performing overhead butt welds, a backing strip can be used.
However, the weaving technique should not be used on lap or tee joints in this position.
For fillet welds, the arc should be kept at a short distance and the welding rod at a thirty-degree angle to the vertical metal plate.
Creating a longer arc distance can be achieved by using a whipping motion away from the welding puddle and in front of the actual weld.
For heavy materials, multiple layers of welds may be required, which is known as “multi-pass” welding.
When making multiple passes in the overhead arc welding position, an angle of approximately fifteen degrees is advised for the welding rod.
To ensure better control of the weld, the circular welding technique is recommended.
Lastly, it is crucial to clean off slag and other materials after each bead using a wire brush and/or chipping hammer.
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Did You Know?
1. Did you know that overhead arc welding, also known as “vertical down” welding, is preferred in certain cases because it creates stronger welds?
2. In overhead arc welding, heat management is critical. One method to control the heat is using a technique known as “whipping” or “stitching,” where the welder rapidly moves the welding torch back and forth.
3. To prevent weld spatter from flying and causing potential harm during overhead arc welding, anti-spatter sprays or gels can be applied to the surrounding area for protection.
4. Overhead arc welding can be more challenging than other welding positions since gravity affects the flow of molten metal. As a result, welders must adjust their technique to compensate for the downward pull.
5. While overhead arc welding is commonly used for structures like bridges or ships, it is also essential in constructing offshore oil rigs, giving them the required strength to withstand harsh marine environments.
Bead Welding For Overhead Arc Welding
Bead welding is a commonly recommended technique for performing overhead arc welding. This method involves joining two metal plates by creating a continuous bead along the joint. When welding in the overhead position, it is crucial to ensure that the bead is smooth and clean before moving on to the next one. Be sure to remove any rough parts of the bead and clean it thoroughly to maintain the quality of the weld.
Stick Angle For Laying Beads On Metal Plate
The stick angle is vital for achieving high-quality welds in overhead arc welding on metal plates. When working with .25″ or .5″ metal plates, it is crucial to establish the correct stick angle. Visual illustrations, specifically illustrations B and C, demonstrate the appropriate stick angles for these thicknesses. To guarantee good root penetration, it is essential to maintain a ninety-degree angle with the stick when creating the first bead.
Tips For Ensuring Good Root Penetration
Achieving good root penetration is vital in overhead arc welding to ensure a strong and durable weld joint.
To achieve this, it is important to have the stick at a ninety-degree angle for the first bead. This angle allows the welding arc to penetrate deeply into the root of the joint, leading to a robust weld.
By focusing on maintaining the proper stick angle, welders can ensure a high-quality weld with excellent root penetration.
- Proper stick angle is crucial for good root penetration
- Stick should be at a ninety-degree angle for the first bead
- Deep penetration into the root is important for a strong weld joint.
“Achieving good root penetration is vital in overhead arc welding to ensure a strong and durable weld joint.”
Choosing The Right Welding Rod Size
Selecting the appropriate welding rod size is crucial for successful overhead arc welding. Using a rod that is too big for the weld can make it challenging to maintain a short enough arc distance. This can result in an inconsistent and inefficient weld.
It is recommended to choose a welding rod size that matches the thickness of the metal being welded. By using the right welding rod size, welders can effectively control the arc distance and achieve a strong, uniform weld.
Techniques To Avoid And Recommended Techniques For Overhead Welding
In the overhead welding position, it is important to use the right techniques to ensure a successful weld. The article suggests avoiding the weaving technique for overhead welds on lap or tee joints, as it may result in an inconsistent and weak weld. Instead, a circular welding technique is recommended for better control.
For fillet welds, it is crucial to keep the arc at a short distance from the metal plate and maintain a welding rod angle of thirty degrees to the vertical surface. This technique helps ensure proper fusion and a strong weld joint. Additionally, a whipping motion away from the welding puddle crater and in front of the actual weld is recommended. This motion creates a longer arc distance, allowing the molten metal to solidify and result in a sound weld.
Cleaning And Maintenance After Each Bead
After completing each bead in overhead arc welding, it is crucial to clean and maintain the workpiece properly. Slag and other materials should be removed using a wire brush and/or chipping hammer. This helps maintain the integrity of the weld and ensures a clean surface for the next bead. Regular cleaning and maintenance after each bead will contribute to the overall quality and longevity of the weld.
By following these tips and techniques, welders can perform overhead arc welding like professionals. With the correct stick angle, appropriate welding rod size, and proper bead welding techniques, achieving high-quality overhead welds is achievable.
Additionally, following recommended cleaning and maintenance procedures ensures that the welds remain durable and visually appealing.
Remember, practice and experience are key to improving your skills in overhead arc welding, so keep practicing and strive for perfection in your welds.
- Clean and maintain the workpiece after each bead using a wire brush and/or chipping hammer
- Maintain correct stick angle and use the appropriate welding rod size
- Practice and experience are essential for improving overhead arc welding skills.
Frequently Asked Questions
What is the overhead technique in welding?
The overhead technique in welding involves performing the welding process from underneath the joint, with the metal pieces positioned above the welder. This position is known to be challenging and intricate, demanding a high level of skill. Welders often find themselves lying on the floor to gain access to the joint and accurately execute the welds. The overhead technique requires careful control and precision to ensure proper fusion and joint integrity, making it a notable aspect of welding that showcases the expertise and adaptability of skilled welders.
What is the angle for overhead welding?
When it comes to overhead welding, the appropriate angle for the electrode is crucial. The ideal angle for overhead welding is typically between ten to fifteen degrees, and it should be moved in the direction of the weld. By maintaining a proper travel angle, you can ensure a successful and effective overhead arc welding technique.
What electrode is used for overhead welding?
For overhead welding, the ideal electrode to use is the 7018. Specifically engineered for this purpose, the 7018 exhibits a lower iron powder content, as classified by the AWS (American Welding Society). This electrode boasts the unique ability to create a weld puddle that rapidly solidifies, ensuring it does not drip off during the welding process.
Why is overhead welding difficult?
Overhead welding presents unique challenges due to the force of gravity working against the welder’s efforts. The welding process involves creating a liquid weld pool, which tends to sag or drip when working in overhead positions. This natural tendency of the weld pool makes it significantly harder to maintain control and produce high-quality welds. The welder must overcome these difficulties by employing specialized techniques and maintaining proper positioning and torch angle to ensure consistent and accurate welds overhead. Additionally, due to the restricted vision and limited access when welding overhead, it requires extra skill and precision to navigate the confined space and produce satisfactory welds.
