phosphorc acid work ok to clean weld for painting.leaves white film ,wire wheel of.Newer anti spater sprays ok but all ways READ LABLE!!!! Plus get your heat treat # from steel vender you can get chemical copposition of material some times called MTR material test report.When welding STAINLES STEEL the crome turns in hexovalient crome very bad on nervis system.plus magnesium in weld rods can cause mag madness.Tungstion 2% thrioum is radio active. I spell like a little kid so bare with me