1. Ngati itagwiritsidwa ntchito ndikusungidwa malinga ndi mitundu, siziwoloka
Pewani kulumikizana ndi oxides, chinyezi / chinyezi, kutentha
2. Imakhala ndi chinyezi komanso kuyaka, kuti isungidwe mufiriji, ndipo kutentha kwa kugwiritsa ntchito sikuyenera kupitirira 80 OC.