Iglasi epholileyo okanye iglasi eqinisiweyo, yenziwa ngokufudumeza iglasi ene-annealed kubushushu obumalunga ne-650 °C(1200°F) ize ipholiswe ngokukhawuleza ngomoya.Le nkqubo itshixa umphezulu weglasi kuxinzelelo oluthi lunyuse ngamandla iglasi.Xa ishushu ngokupheleleyo le glasi yomelele ngokuphindwe kane kuneqhekeza leglasi.
Okubaluleke ngakumbi, xa ikhefu linomsindo liyahlukana libe ngamaqhekeza amancinci athathwa njengepatheni ekhuselekileyo.