Presently, this relates to MIG, but will relate to TIG later... When in the Navy, all the welding I did was under shelter, in moderate temperature. A year or two ago I had some outdoor work on relatively heavy metal, 1/4"+ thickness, it was cold, freezing temps (yes, in FL) and I seemed to have nothing but trouble. On a whim, we decided to hit all the joints with a MAPP torch, thinking the cold was messing with things. It might have been a coincidence, but it started going much easier, easier starting, cleaner welds, better penetration.

Well, we're hitting 30-40 temps now and I'm wondering if there's a point where it makes sense to warm the metal before welding for better welds. Thoughts?