A method for batch brazing in a diffusion furnace includes inserting a plurality of fusible parts into a plurality of slots of at least one quartz boat, transporting the at least one quartz boat, including the fusible parts, into an interior of a reaction chamber of the diffusion furnace, sealing the interior of the reaction chamber, adjusting an atmosphere of the interior of the reaction chamber according to a recipe, moving a preheated furnace heating element from a location spaced apart from the reaction chamber to a location in substantial proximity with the reaction chamber to increase a temperature of the atmosphere of the interior of the reaction chamber above a predefined brazing temperature for a predefined brazing time period according to the recipe.