There is no defined shelf life for TotalBoat Halcyon water-based marine varnish if it has been stored properly. In most circumstances, Halcyon that has sat for a number of months or even years can be mixed or shaken to be reconstituted if it has settled at all. If Halcyon varnish has not been properly sealed during storage, it may become thicker. Adding 5-10% water may revert Halcyon varnish to its original viscosity and flow, however, Halcyon that does not successfully revert by adding 5-10% water should not be used.
Halcyon varnish is quite resilient to freezing and thawing, however, Halcyon that has been stored through many freeze/thaw cycles should always be tested for proper flow and cured properties prior to using.