Originally Posted by leon bee
You just buy a bag of the corks and replace the old ones.

that is exactly what i did , but being a pedantic ex engineer i got hold of some real high grade cork (yes there are something like 5 grades of cork) and machined them down to get a good tight fit (from memory i settled on 1/2" diameter and made a little tool with a huge tapered lead in to size them to the id of the tap and boiled them before putting them in the "fixture which i froze overnight) ,,, i just soldered the spigot back on .....worked a beauty .........5 years of no leak and counting

most important is to deburr inside theof tinny little thread where the lock screw goes or it will tear the cork on insertion..........pedantic hell yeah!