What happens if a joint is wiped while still hot?

Wiping a joint while it is still hot can lead to a crack in the bond because the mechanical action of wiping disrupts the solidifying solder. When solder is exposed to rapid changes in temperature or stress while it is still in a malleable state, it can cause the material to strain and ultimately crack or weaken the joint. This is particularly crucial since the integrity of the soldered connection relies on a solid, uniform bond formed during the cooling process. Proper cooling allows for adequate time for the solder to crystallize and settle into a strong, reliable bond. Thus, a hot joint that is wiped can damage the overall quality and strength of the soldering work, leading to a compromised joint that may fail under stress or load.