(Please ignore the flame at the neck in the torch; I fixed that a minute or so later once I realized what was up.)
Damn mower steering gear kinda stripped again today, and I don't really want to buy another replacement.
Last time I tried this, the gear teeth failed due to porosity, which is hard to avoid with MIG. (I resorted to welding, then grinding back the weld until I saw no more porosity, then putting in another pass...slow going, to say the least.)
Theoretically, O/A welding lets you take the time to pick the impurities out of the weld, or at least to burn them out and fill in the pinholes as you go. In practice, well, it worked better than MIG but it wasn't perfect. My technique also needs work since I just kind of dove right in rather than doing a practice piece.