Why A lightning strike dumps tens of thousands of amperes into the ground conductor, and the resulting I-squared-R heating in the joint far exceeds the melting point of solder (around 180-190 C for common tin-lead alloys). The joint would melt and open the path just when it is needed most, letting the surge find another route through the station. Lightning ground connections must be made with mechanical means, brazing or exothermic welds, and the bonding conductors should be heavy and as straight as practical.