Mason jar lids have a thin rubber seal either on a lid that a rim screws down onto or under the a one piece lid. Yours is probably worn and no longer air thigh. Find a store that sells canning products ( many grocery stores actually sell them ) and buy a replacement.
Just get another, not worth the trouble. Might have worn seal or chipped glass
Generally as a set, you have the jar, a cap, and a ring.
The seal is generally with the cap so the ring will not seal with out it. If you can find a single rubber ring the size of the cap you could get the metal ring band to seal.
I did see some really neat painted caps made especially to fit mason jars, they had a hole in them and came with a fitted straw for like summertime outdoor party drinks.
I bought a mason jar to use it as a drinking cup not to preserve stuff. The lid is completely metal and the liquid inside the cup leaks out. What can I use or buy to stop the leakage?
