That's all I ever saw used, I didn't see the production though just the repairs and mods. Not many on the airframes but the engine mounts would crack a little more often due to the vibration and the older stuff landing on frozen lakes with skies got a little bumpy. I didn't do all the repairs but it was my license signing them out so I had to know a good qxy/actl weld when I saw one. Arc is another animal to me.