Results and Conclusions:
It is recommended to use brazing alloy preforms / rings instead of a brazing rod. This allows the user to use both hands to hold the U-Braze. It also improves the quality of the braze and repeatability by distributing the correct amount of alloy all around the braze joint every time.
When brazing copper to steel, it is best to preheat the copper to avoid overheating the steel piece since the copper is harder to heat.