Kwiyitirira gutwikira birimo gutesha agaciro (degreasing), gukuraho ingese, fosifati ibice bitatu.Fosifatiya ni ihuriro nyamukuru, gutesha agaciro no gukuraho ingese ninzira yo kwitegura mbere ya fosifatiya, kubwibyo rero mubikorwa byo kubyaza umusaruro, ntitwakagombye gufata akazi ka fosifati gusa nkibibandwaho, ahubwo tunatangirira kubisabwa byujuje ubuziranenge, gukora akazi keza usibye kuvanaho amavuta n'ingese, cyane cyane witondere ingaruka hagati yabo.