It sounds to me like you mayb welding to slow and over heating the material. When you finish your bead if you are holding the torch over the weld until the post flow runs out, that will cause that last bit of the weld to turn out really nice and color because the weld is sheilded until it has time ...

Hi Folks, I am relatively new to TIG, and am practicing welding some 18GA, 3" 304SS Stainless Exhaust Tubing. I am using 1/16 2% Lanthanated Tungsten, .04" Filler (308L?). Backpurging with Argon, #8 Gas Lens, ~15CFH flow rate. I think my peak amperage on the welder is set @ 35A I know that...