Re: A question on mig welding technique
Your question is going to generate controversey among two seperate groups of welders. the stitching technique is best suited to machines with a stitch timer that will control the after flow of shielding gas to prevent weld contamination. Several well respected chassis fabricators I know use the sticth weld, their work is beautiful and stands up to crashes. One of the advantages to it is that the stresses created in the weld process seem to cancel themselves out. I follow a different line of thinking that is similar to CJ Dave, I am fast and furious I weld all the way around the tube in one shot, my welds look more like a machine made weld, the disadvantage of this method is joint fit is absolutely critical, a few thousanths gap will be horribly disfiguring.
My best advice is to practice with some 1" .090 wall tubing, try to build an equalateral triange and a square with 18" sides, if you can build these so that you can trace them on the floor with chalk, and flip or rotate them in any direction and still fit the outline then you will have a good lesson under your belt.
good luck, jjc