Iron Phosphating

pH not in range (see “Poor Cleaning”)

Adjust pH (down with acid, up with Caustic)

De-greasing in bath

Increase the bath temperature

Temperature too low

Increase concentration of the bath

De-greasing in bath

Check racking and nozzles

Concentration too low

Check pressure

Poor exposure to cleaner solution

Increase the pressure if necessary

Phosphate Coating too heavy

Lower temperature, lower concentration

Contamination

See “Poor Cleaning”, look for source of silicone near washer

Bad steel

Check raw material for excessive oil

Coating weight too low

See “Trouble Coating Weight too Low”

Dry-off too slow

Increase temperature in the final rinse using air blow off

Drying between stages

Run at lower temperatures, better placement of nozzles

Contamination rinses

Check rinse tanks

Poor cleaning

See “Poor Cleaning”, check racking

Poor exposure

Check nozzles

De-grease bath temperature too low

Increase the bath temperature

Pressure too high

Check for plugged nozzles

Pumps picking up air

Check pump packing, check water level