Various technologies exist whereby components of reactive mixtures that are capable of curing over time to form polymeric coatings and other manufactures are brought together with one another to form such reactive mixtures. Frequently, such components are supplied to end users in separate containers, which may be metal cans. At the time of use, the correct amount of each substance from such separate containers are combined in a third container, mixed until uniform, and then the mixture is used as desired. Some embodiments of the prior art include partially filling a vessel with one component of a reactive mixture and subsequently adding a selected amount of a second component of a reactive mixture. Such prior art method can easily result in incorrect stoichiometry of the reactive components being mixed together, and creates waste materials which are left coating container walls.