Mkpuchi pretreatment na-agụnye degreasing (degreasing), mwepụ nchara, phosphating akụkụ atọ.Phosphating bụ njikọ dị n'etiti, nkwụsị na iwepụ nchara bụ usoro nkwadebe tupu phosphating, ya mere na mmepụta mmepụta, ọ bụghị nanị na anyị ga-ewere ọrụ phosphating dị ka ihe a na-elekwasị anya, kamakwa malite na ihe ndị a chọrọ nke àgwà phosphating, rụọ ọrụ dị mma na mgbakwunye. mmanụ na mkpochapụ nchara, karịsịa ṅaa ntị na mmetụta dị n'etiti ha.