TWI Frequently asked questions
The following fabrication techniques can be used to prevent formation of lack of sidewall fusion imperfections:
- use a sufficiently wide joint preparation
- select welding parameters (high current level, short arc length, not too high a welding speed) to promote penetration into the joint side wall without causing flooding
- ensure the electrode/gun angle and manipulation technique will give adequate side wall fusion
- use weaving and dwell to improve side wall fusion providing there are no heat input restrictions
- if arc blow occurs, reposition the current return, use AC (in MMA [SMA] welding) or demagnetise the steel
For more extensive information on lack of fusion defects, see
Job Knowledge for Welders 41 - Weld defects/imperfections in welds - lack of sidewall and inter-run fusion
Copyright by TWI, 1999
