It so happens at times since copper is not as tensile as steel, the caps might become sturdy to tighten, in this case putting a little oil around the rings of the seal of the cap and the rim of the bottle and putting it away for a certain amount of time resolves the issue. The grease in the oil will bring back the cap to its proper functioning again.
It so happens at times since copper is not as tensile as steel, the caps might become sturdy to tighten, in this case putting a little oil around the rings of the seal of the cap and the rim of the bottle and putting it away for a certain amount of time resolves the issue. The grease in the oil will bring back the cap to its proper functioning again.