That’s exactly what that greying is. Hot tungsten attracts it and it sticks. Sometimes a simple buffing with scotchbrite and or fine sandpaper will do the trick as long as you take it back to good shiny tungsten. I always light up on a scrap piece before I start with a newly prepped tungsten to burn off any of the impurities caused by the grinding or polishing.

Thank you Michael. Enjoyed the conversation.

Nice.

I wouldn’t say it’s harder, but what it does is teach you how to constantly watch your puddle , feed filler wire and adjust amperage constantly just due to the properties of Aluminum. There are a lot of different things going on at one time. I think it’s advantageous to learn Aluminum even if you don’t do very much of it at a production level. The skill set you will acquire is worth the effort and I feel like it transfers to other material types easily.

Nice.

Absolutely Thanks Martin.

I actually have the polarity backwards in the photo.

Haha. Thank you bud.