Metcal pct 100 focussed convection pre heaters metcal pct 100 21 the metcal pct 100 focus pre heater produces targeted heat for improved speed and efficiency when soldering high thermal demand applications including lead free used for smt and through hole hand processes the pct 100 uses convection air heating to pre heat a pcb for better soldering improved process control and increased productivitythe pct 100 focus pre heater adds heat volume without turning up the soldering iron tempe