Many no-lead or lead-free alloys use special chemicals in their composition, making heat diffusion more difficult. As a result, it is more challenging for solder to adhere to no-lead silicon brass ...

This signals that it's time to apply solder. Now, move the flame away and touch lead-free plumbing solder to the joint. If the joint is horizontal, start at the bottom.

Company boss also tells inquiry he only learned the sourced solder bars were 50 per cent lead in composition after the scandal broke in July ...