Troubleshooting guide to iron phosphatizing

Problem, Cause and Remedy

PROBLEMCAUSEREMEDY
Poor CoatingpH not in range.
See “Poor Cleaning.”
Adjust pH down with acid,
up with caustic.
Poor CleaningTemperatures too lowRaise temperature
Concentration too lowIncrease concentration
Poor exposure to cleanerCheck racking.
Check nozzles.
Check pressure,
15-25 psi.
Spotty Coating/ StreakingContaminated rinses
Poor cleaning
Check rinse tanks.
See“Poor Cleaning.”
Contaminated rinsesCheck rinse tanks
Poor exposureCheck racking.
Check nozzles.
RustingCoating weight too lowRaise temperatures.
Lengthen time.
Increase concentration
Dry-off too slowIncrease temperature in final rinse.
Drying between stagesRun at lower temps.
Better placement of nozzles.
Use fog nozzles
Solutions FoamingTemperature too lowRaise temperature
Pressure too highCheck for plugged nozzles
Pump picking up airCheck pump packing.
Check water level.
Poor Paint AdhesionCoating too heavyLower temperature.
Lower concentration.
Poor cleaningSee “Poor Cleaning.”
ContaminationLook for source of silicone near washer.
Bad steelCheck raw material for excessive soil.