Apparatus and a method for sealing of protective barrier fabric seams in otherwise impermeable articles such as garments, footwear, surgical gowns and the like, are provided, the sealed seams maintaining the imperviousness of the article, including seamed joints, to water, body fluids, pathogens and chemicals. In one pass through the apparatus, a sealed seam in a protective barrier fabric joint, using a curable adhesive sealant, is provided along a predetermined and specified length of the joint. The preferred adhesive is a silicone, most preferably a two-part, thermosetting silicone elastomeric adhesive. Also provided are mixing dies for use, inter alia, in the process which are especially suited for applying the two-part adhesive sealant. In addition, variable-residence-time curing apparatus, which effects variable, controlled, desired cures of the adhesive, all in a one-pass operation, is provided, together with precise metering pumps, especially suited for supplying the seam sealing adhesives in the process of the invention.