Kūleʻa ke kila kila i ka ea, ka mahu, ka wai a me nā mea palupalu palupalu a me ka waikawa, alkali, paʻakai a me nā mea ʻē aʻe etching medium corrosion o ka paipu kila, ʻoi aku ka mānoanoa o ka pā, ʻoi aku ka waiwai a me ka hana, ʻoi aku ka lahilahi o ka mānoanoa o ka pā. , e pi'i nui ana kona kumukū'ai hana.I ke kulou ʻana, like ka ikaika torsional, māmā ke kaumaha, no laila hoʻohana nui ʻia i ka hana ʻana i nā ʻāpana mechanical a me nā hale ʻenekinia.