by Jason Becker
Push vs. Pull with Gas Metal Arc Welding has been a long standing debate in the welding industry. We set out to run this test from a completely unbiased, fair and scientific approach.
We kept all of the variables the exact same, except for the direction of travel. For this experiment, we used a MIG welding tractor so that we could ensure that we were able to maintain the same travel speed, work angle, contact tip to work distance, and travel angle. Additionally we used the same machine settings to conduct both welds we set the machine at 550 ipm for the WFS and 31.5V. Everything was kept the same and we ran an 8" sample for each specimen and cut the center out at the same spot in each specimen.
We decided to get both pieces tested by a professional so we reached out to Select Arc Inc who offered us a chance to use their lab to test the results. Select Arc Inc. We took the pieces to their brand new, state of the art lab where they were able to do a cut and etch on the specimens and perform a Microetch inspection.
They started by cutting out the sections from the specimens we prepared by using a wet saw and then mounted the samples into a 2 part epoxy. Once the epoxy was dried, the pieces went through various stages of polishing until both pieces had a mirrored finish. The lab tech then put the final pieces under the microscope and gave us the results.
It was definitely not what I was expecting, the two samples showed no significant difference. I personally thought for sure that the push sample would have a deeper penetration profile than that of the pull sample. The lab tech was under the same assumption. Although this test isn't the definitive answer as to which technique is better and provides better penetration, we think it's pretty close. Thanks for reading and until next time, Make Every Weld Better Than Your Last.