Can we all agree on which tungstens are best for which applications? I can look online and find sites that are saying the exact opposite of each other regarding this. Which polarities to use and for which metals are all over the map. I am a welding instructor and it is frustrating having to tell peo...

Other than " all the way up" are there any settings that you can recommend? It's a butt joint extending a piece of 5" x .25 wall Al tube, alloy is 6061 T6 511. We have a torch cooler and a Speedway torch.