Project 1 from DaveO (210 Ext contest): shelf repair

One of my chores this past weekend was to disassemble a large modular shelf unit and reassemble: it was too large to fit through the door of the new space. The shelves are steel heavy duty monsters: 7' uprights connected by 1" steel tubes that support the shelves. The tubes are threaded male and female at the ends; the threaded sections are inserts that are welded into place. During disassembly I had a pipe wrench on a tightly fitted end, and broke the original weld.

The first photo shows the threaded female end I broke, old welds ground off and cleaned up for repair, with an example of the manufacturer's finished product on the right. The tube opened up at the end, with all my wrenching; I tried to hammer it back into round but couldn't get there. Note the seam in the threaded plug: apparently this was manufactured flat, and then bent into round to form an elongated nut.

Next photo shows the rod prepped for welding: I used the male end of another rod to hold the threaded insert, and clamped it into position.

Next photo, the weld itself, using the IMIG 200 on 110v power, .030 wire, and about 85 amps: I'm kicking myself in retrospect because I didn't set myself up to succeed- should have positioned myself better and performed the weld differently. Lesson learned for next time. I also realized during all this that a breeze was starting to pick up in my open air workshop, so I'll find a sheltered spot to work next time.

The tube also had openings for welds on opposite sides of the threads: next photos are before and after shots.