Updated: Apr 6
by Jason Becker
Today we are closing out the welding defects/discontinuities series and covering the remaining 2 defects. The first one we discuss is unequal leg length. This is pretty simple defect to fix. Improper leg length is more than likely caused by improper work angle.
You always want to ensure that you are bisecting the weld joint to get 50% of the weld metal on each of the two pieces. Now, there are a few occasions where unequal leg length are required. One example would be 2 plates with different thicknesses; say for instance a 1/4" plate and a 1/2" plate. In this case, you may be asked to perform a weld with unequal leg lengths, and should be depicted with the appropriate welding symbol. Another time unequal leg length would be applicable is for fit-up reasons where an equal leg length would interfere with adjoining parts.
The last defect we would like to cover is underfill. Underfill is probably the best welding discontinuity you could have. And that is simply because it is a quick and easy fix to make. All you have to do is finish filling the weld joint until it is flush or below the maximum allotted weld reinforcement depending on material and thickness. Another big help in eliminating underfill, is proper use of run-on/run-off tabs. Too often these tabs are not utilized to their full potential and as a result, the welder fails a test for underfill. I used to tell my students that these tabs are one of the most important but underutilized part of the test piece. Use them to your advantage, thats what they are there for.
I hope you all enjoyed this series of welding defects and that you were able to learn some of the common mistakes and remedies for each discontinuity, so that they wont become defects. Until next time, Make Every Weld Better Than Your Last!