I am trying to come up with a method to prevent sugaring on flat strip stainless Tee joints, 18ga 304. I want to run a single TIG pass on both sides of the joint and prevent sugaring from the first pass on the first side. This is for a classroom demonstration on backpurging for students to visually see the need and reason why. Any ideas would be appreciated. I am thinking about fabbing a argon dam sort of thing to create an argon atmosphere on the back side to prevent sugaring and allow it to be removed for the final pass, and then place this dam on the opposite side. Is there such a thing..Thanks for any thoughts or ideas, Walt