In the 96 years Berryman Products has been making its tire sealant, we are proud to say we have no record of a complaint regarding the product losing its fluidity or mobility after application. As it relates to shelf-life, we guarantee all our products to have a shelf-life of at least two years. However, our experience on Tire Seal-R far exceeds this standard. In fact, our tire sealants have been found in barns and garages after more than 40 years and still remained liquid and viable. It is important to understand that, upon breaking the seals of the one-gallon and five-gallon products, resealing them with either the cap or screw-on pump will prevent the formation of a “skin” on top, much like open paints and glues can exhibit. Resealing Tire Seal-R in this manner is the key to a longer storage life.