/diy/ - Do It Yourself

im new to welding but cant find answer

whats this brown stuff ontop of weld? it wipes away after touching, i looked online and some people said it means not enough gas or, it's just normal when the metal comes into contact with air after weld?
does it mean i need more gas, or is it normal? the welds themselves grind down smooth and penetrated the back, the back side of it is clean and doesn't have it

this is at about 7/L min with 75/25 argon mix, the welder has a thing saying recommended gas flow and it says 5L min for 0.8mm, i turned it up a tad because theres wind