What is Backhand Welding Technique?
Backhand Welding Technique involves moving the torch tip ahead of the welding rod in the same direction as the weld. This differs from the forehand welding method, where the flame is directed towards the welding rod and the puddle.
When using backhand welding, the torch should move steadily down the groove without any oscillation, while the welding rod may be moved in circular or semicircular motions within the puddle.
This approach results in the creation of smaller puddles and requires a narrower V-groove with a 30-degree bevel or 60-degree included angle compared to the forehand welding method. Consequently, backhand welding provides more precision and can help lower overall welding expenses.
Backhand Welding Advantages
The advantages of the backhand welding technique are:
- Greater control over the weld
- Reduced cost due to the use of less filler material
- Improved penetration into the base metal resulting in a stronger weld
- Reduced heat input into the base metal, preventing distortion or warping
- Particularly suitable for thick metals allowing for deeper penetration and stronger welds.
Related Reading: Welding Techniques: Leftward Welding and Rightward Welding
Backhand welding vs forehand welding
|Aspect||Backhand Welding||Forehand Welding|
|Torch Position||The torch is positioned ahead of the welding rod in the direction of the weld||The torch is positioned behind the welding rod|
|Flame Direction||The flame is directed towards the puddle and the welding rod||The flame is pointed back at the puddle and the welding rod|
|Torch Movement||The torch moves steadily down the groove without any oscillation||The torch may be moved in an oscillating motion|
|Welding Rod Movement||The welding rod may be moved in circular or semicircular motions within the puddle||The welding rod is moved in the opposite direction of the weld|
|Puddle Formation||Backhand welding results in the formation of smaller puddles||Forehand welding results in the formation of larger puddles|
|V-Groove Requirements||Backhand welding requires a narrower V-groove with a 30-degree bevel or 60-degree included angle||Forehand welding requires a wider V-groove with a 45-degree bevel or 90-degree included angle|
|Advantages||Greater control, reduced cost, improved penetration, reduced heat input, suitable for thick metals||Higher deposition rates, better visibility of the weld, suitable for thinner metals, requires less skill|
Disadvantages to using backhand welding
While the backhand welding technique offers several advantages such as faster travel speeds, stronger welds, and better control over the weld pool, it also comes with some disadvantages. Some of the drawbacks of using the backhand welding technique include:
- Higher heat input: Backhand welding typically results in higher heat input compared to the forehand (pushing) technique. This increased heat can cause more distortion and warping of the base material, particularly on thin or heat-sensitive metals.
- Limited joint access: The backhand technique may not be suitable for welding in tight spaces or confined areas, as the torch angle and electrode manipulation can be more challenging compared to the forehand technique.
- Less control over bead appearance: While backhand welding can produce strong welds, the technique might result in wider, flatter, and more irregular bead appearances compared to the forehand technique, which often produces a more aesthetically pleasing, narrower, and uniform weld bead.
- Increased risk of incomplete fusion: Due to the faster travel speeds and higher heat input, backhand welding may increase the risk of incomplete fusion, particularly if the welder is not experienced or if the joint preparation and fit-up are not optimal.
- Less suitable for out-of-position welding: The backhand technique is generally more challenging to use in vertical, overhead, or other out-of-position welding scenarios, as the weld pool control becomes more difficult.
These disadvantages should be considered when selecting a welding technique for a specific application. The choice between backhand and forehand welding often depends on factors such as material type, joint configuration, welder experience, and the desired weld quality and appearance.