A method for manufacturing a septum polarizer includes dispensing a layer of adhesive on a first contact surface of a first substrate, attaching the first substrate to a second substrate to form a combined structure, and elevating the combined structure to a first temperature that is above a first cure temperature of the adhesive for a predetermined period of time. The method further includes after attaching the first substrate to the second substrate, applying a continuous metallization coating over each outer surface of the attached first and second substrates, and elevating the combined structure and metallization coating to a second temperature, thereby curing the metallization coating without degrading the layer of adhesive. The metallization coating has a second cure temperature that is lower than the first cure temperature of the adhesive, and the second temperature is above the second cure temperature and below the first cure temperature.