Mig welding around old brazing and lead panels?

[BOWTIEGUY]

Made some repair panels for my 33 Chevy coupe. Noticed that the areas where I plan the butt welds have a lot of old brazing joining the panels. The lead is easier to remove...but is there a special procedure to follow before starting the mig around brass? The car is 18 ga and the panels I made are also 18 ga.

Thanks

[Daniel]

You have to get rid of the brass, I'de use a little die grinder. Takes time.