A boiler that one coated with mortar or potters’ clay: That which touches the mortar is tamei while [that which touches] the potters’ clay is tahor. A kettle that developed a hole and one repaired it with pitch: R’ Yose rules it tahor because it cannot hold hot [liquids] as [it does] cold [liquids]. And that is how he used to rule concerning utensils of pitch. Copper utensils coated with pitch are tahor, but if [meant] for wine, they are tamei.