Question concerning welding?

I have a mig welder which is set up to weld mild steel. I don't have the proper gas to weld stainless steel. I have a roll of stainless steel wire and a tank of 75% Argon and 25% carbon dioxide. I have a very small weld to make. I'm more concerned about the appearance of the weld than its strength. Will I be able to clean this weld so it doesn't look too bad. The actual job: Weld a 3/8" round SS rod at 90 degree angle onto another rod the same size and material. Thanks