ʻO PPGI & PPGL (ke kila i hoʻopaʻa ʻia a me ke kila galvalume i hoʻopaʻa mua ʻia) i ʻike ʻia ma mua o ke kila kila a i ʻole ke kala i uhi ʻia i ke kila kila, He huahana i hana ʻia me ke kila kila wela, ka ʻili wela wela, ka pā kila electro galvanized, etc. Ma hope o ka hoʻomaʻamaʻa mua ʻana i ka ʻili, hoʻopili ʻia hoʻokahi a i ʻole kekahi mau ʻāpana o ka hoʻopili organik ma ka ʻili, a laila kālua a paʻa. He māmā ke kaumaha o ke kala i uhi ʻia, nani i ka helehelena, a he maikaʻi ka hana anti-corrosion, a hiki ke hana pololei ʻia. Hoʻokaʻawale ʻia ke kala i ka hina, ke kai uliuli, ka ʻulaʻula brick, etc.