<p>A method is provided for joining a filler material to a substrate material. The method includes melting the filler material within a melting chamber of a crucible such that the filler material is molten. The crucible has an outlet fluidly connected to the melting chamber. The method also includes holding the filler material within the melting chamber of the crucible by applying a first pressure differential across the outlet of the crucible, and releasing the filler material from the melting chamber of the crucible by applying a second pressure differential across the outlet of the crucible to deliver the filler material to a target site of the substrate material. The second pressure differential has a different value than the first pressure differential.</p>
