In the US Army Metalworking school 44B, we mastered Oxy/Acet in the flat, verticle, and overhead positions, each position was countless coupons and countless types of welds, for about 2 weeks 8-9 hrs a day we did this, then, moved to Arc doing the same thing, same positions but using 6010, 6011, 7010, 7018, etc rods, this was about 3 weeks long, we could not move on to the next discipline until mastering these. Then, we moved into Mig, all the before mentioned methods, coupons and positions had to be mastered, then, add another week using the Mig gun with aluminum; same positions as before but with aluminum coupons. Then, after this process, we did Tig, same coupons, same positions, with steel, then, with aluminum. Let me tell you, it was threading the eye of a needle! BUT...I respect folks that went thru this training, the proof is in the weld!