Patent ID: 7028921

Claim:
A dispenser for use in combination with a spraying apparatus for applying a liquid coating formulation to a surface to produce a finished coating, the liquid coating formulation having “W” weight percent of solids therein, the spraying apparatus having a housing with a flow channel extending therethrough and a reservoir for holding the liquid coating formulation, the reservoir being open to the atmosphere and being in fluid communication with the flow channel, the reservoir having a cross sectional area “A”, wherein the dispenser comprises: a generally tubular body member having a closure at both a first and a second end thereof, the dispenser holding a predetermined volume of a polymerization catalyst solution having “w” weight percent of catalyst therein, the tubular body member having a predetermined cross sectional area “a”, wherein the cross sectional area “a” is given by the relationship: a≅P·A·[W/w]· 10 −6 , where P is the ratio by weight of the catalyst to the solids desired in the finished coating, in parts per million, so that, in use, after opening of the closure at the first end, when the dispenser is insertable into a liquid coating formulation in the reservoir to a position such that, after opening of the closure at the second end, the liquid head of the liquid coating formulation in the reservoir prevents flow of the catalyst solution from the dispenser until the liquid coating formulation flows from the reservoir into the flow channel, whereby the catalyst solution mixes with the coating formulation in a way that a predetermined concentration of the catalyst solution is maintained as the liquid coating formulation flows from the reservoir.