Lead-free wave soldering requires tighter process control than soldering with lead based alloys. A key area of the machine that impacts the ability to solder lead-free alloys without defects is the fluxer system. A large variety of fluxers are available for use with lead-free soldering - each having advantages and disadvantages. This paper compares the more popular flux systems in terms of through hole penetration, coverage accuracy, cost level, maintainability, and chemical compatibility. Ultrasonic, air atomization, and jet type flux systems are discussed and test data presented for each system.