In an ideal world, this would never happen, but sometimes I find that I cannot cut away all damaged metal and must deal with blow through when welding patch pieces in. Do you have any tips/suggestions for minimizing blow through (other than cut more metal away)?
A.If you find yourself in a situation where you’re having trouble blowing through, you can clamp a 1/16″ or thicker piece of copper behind the seam to be welded. The copper will keep from blowing through and will not be permanently welded to the weld itself. Sometimes the copper sticks a little but a little tug or twist sets it free.
Wrench safe, Mark