Marty brazes together a trumpet valve section.
At this point the valve casings, symphonic valve braces, and valve connector tubes have been "blocked" together using steel braces. Flux has been applied to the entire valve section which cleans the surface and allows the braze to run smoothly into the joints. The brazing wire used is made from a brass alloy with a melting point just slightly below that of the actual brass. Notice how hot the valve casings and connectors must be before the actual brazing can begin. This high melting point serves two purposes. First, it provides a much stronger joint than that of soft solder making it ideal for high stress locations on an instrument. Second, it allows for future soft soldering of additional parts close to the brazed joint without fear of it separating. Marty runs the brazing wire through a small tube that is held in her hand. This gives her better control during the brazing while protecting her hand from the heat of the wire. After every joint has been brazed, Marty carefully loosens and removes the steel braces and sets the red hot valve section aside to cool.