Kumanga bwino, kuwotcherera kosavuta.
Wabwino kulimba, kukana nyengo, otsika kutentha kukana.
Kapangidwe kake ka kuwira, kutsika kwamadzi otsika, komanso kupezeka kwabwino.
Dzimbiri kukana solvents monga acid, soda, mchere, mafuta, etc.
Ntchito yabwino yotsutsana ndi seepage komanso katundu wotchinga kwambiri.