DETALHESShielding Gas 80%Ar-20%CO2 Notes on usage (1) The optimum flow of 75~85% Ar+25~15%CO2 for shielding is 20~25?/min. (2) The distance between tip & base metal is to be 20~25mm. (3) Protect the weld with a screen to prevent blowholes caused by wind where the wind velocity is 2m/sec and more.