Please *stop* showing viewers Pb-free solder and water soluble flux for non-rework soldering. There is no reason for hobbyists and makers to use that stuff in preference to leaded solder and RMA rosin flux.
Hello and thanks for watching. I agree that pb-free isn't used much by hobbyists or makers. However, I do try to give a complete overview. You will be happy to know that the next video will use good ol' 63/37.
There are some applications where it works better, such as hand-soldering or reworking 0.5mm pitch components. It has different properties, which are not universally “bad”.
