I have changed the earth from negative to positive this is required for flux coredwelcome to the forum, it would help if you told us what had been changed for the polarity switch
Strictly speaking there is no earth in the welding setup, with DC welders there is + and - but mains earth is only connected to the case and should be isolated from both welding wiresI have changed the earth from negative to positive this is required for flux cored
That machine is gas only, have you modified it internally?I have changed the earth from negative to positive this is required for flux cored