Just about every rod I own has a cork handle. After a few years of hard use, the cork starts to break down and eventually fall to pieces. I wear Birkenstock sandals most of the time and part of the sole on the sandals is made of cork. Birkenstock makes a product called "Cork Life" that is used to coat the exposed cork on the edge of the sole when it begins to wear. I used it on some of my cork rod handles, and it seems to work very well and seals out moisture. Cork Life is a white liquid that dries clear and comes in a small jar with a brush applicator. Temperature does not seem to have any affect on it.