With the two frame rails complete, it was time to cut and weld in the cross members.
First, I created a jig to hold the frame rails the right amount apart. To get the spacing right, I cut a couple of pieces of 1/2″ by 1/2″ box section then clamped them to the suspension mounts of the old frame. Next I marked the location of the alignment holes using a transfer punch. Then I drilled holes at the marks straight through the 1/2 by 1/2 box section. Lastly I ran 5/16 bolts through the box section and bolted them to the frame rails. Here is a picture that shows the jig holding the frame rails the right distance apart.
I placed the frame rails on a 3/4 sheet of plywood, levelled the plywood, then clamped the frame rails into place. After checking that the frame was square and level (this took several adjustments), I welded in the cross-members, then looked closely at my welds. Something was wrong. the welds were porous! After a bit of searching I found that the low-pressure gauge on my MIG unit was stuck at 20 psig even with the argon/c02 shut off. It turned out the the housing of the gauge was bent and was pushing on the mechanism. A quick straightening of the housing and re-assembly fixed the problem.
Bob to the rescue!!!! Realizing that I had to grind out the welds and do them again I was overjoyed when Bob offered to come over and help out. As soon as Bob ground out a defective weld, I ran a new replacement weld. We repeated this until all of the welds were re-done. Here is a picture of Bob faithfully and carefully grinding out a defective weld.