Welder Certification Backing Bar vs. Open Root Weld
As with all welding certifications many offer two types of root openings. The first is typical of plate or structural welding certifications and that a backing bar is used. The second is an open root type of weld that is commonly used on pipe welding certifications. These two types of roots both have advantages depending on the type of work being done.
Root with a Backing Bar
Structural welding is typically done using a backing bar so in this situation a backing bar is appropriate. With a backing bar in place it makes the root of the weld easier to do. At the same time this is the way most structural welding jobs will test their welders.
Open Root Weld
When it comes to pipe welding certifications even though they offer a backing bar, it is not very common in the field. In some rare cases they may use a chill ring or backing ring. With pipe it’s always best to go with the open root. As with all open root welds the inside or back of the weld must have full penetration as if it were welded from the back side or inside of the pipe. In the field most welds done on pipe are open root groove welds. Open root welds are harder to do! If you are certifying with SMAW most likely it will be an E6010 root and an E7018 fill and cap. This will typically qualify you for more welding electrodes then say a backing bar using a E7018 electrode alone .Another common combination for a open root pipe welding test is a GTAW root and hot pass with a SMAW fill and cap. This is considered a combo type of test because it certifies you in two welding processes.