Troubleshooting
Iron Phosphating

Coating defects, de-greasing, rusting, poor adhesion

Poor coating formation in phosphating stage

CAUSE
SOLUTION
pH not in range (see “Poor Cleaning”)

pH not in range (see “Poor Cleaning”)

Adjust pH (down with acid, up with Caustic)

Adjust pH (down with acid, up with Caustic)

Poor cleaning in de-greasing stage

CAUSE
SOLUTION
De-greasing in bath

De-greasing in bath

Increase the bath temperature

Increase the bath temperature

Temperature too low

Temperature too low

Increase concentration of the bath

Increase concentration of the bath

De-greasing in bath

De-greasing in bath

Check racking and nozzles

Check racking and nozzles

Concentration too low

Concentration too low

Check pressure

Check pressure

Poor exposure to cleaner solution

Poor exposure to cleaner solution

Increase the pressure if necessary

Increase the pressure if necessary

Poor paint adhesion

CAUSE
SOLUTION
Phosphate Coating too heavy

Phosphate Coating too heavy

Lower temperature, lower concentration

Lower temperature, lower concentration

Contamination

Contamination

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

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

Bad steel

Bad steel

Check raw material for excessive oil

Check raw material for excessive oil

Rusting

CAUSE
SOLUTION
Coating weight too low

Coating weight too low

See “Trouble Coating Weight too Low”

See “Trouble Coating Weight too Low”

Dry-off too slow

Dry-off too slow

Increase temperature in the final rinse using air blow off

Increase temperature in the final rinse using air blow off

Drying between stages

Drying between stages

Run at lower temperatures, better placement of nozzles

Run at lower temperatures, better placement of nozzles

Spotty coating / Streaking

CAUSE
SOLUTION
Contamination rinses

Contamination rinses

Check rinse tanks

Check rinse tanks

Poor cleaning

Poor cleaning

See “Poor Cleaning”, check racking

See “Poor Cleaning”, check racking

Poor exposure

Poor exposure

Check nozzles

Check nozzles

Solutions foaming in de-greasing

CAUSE
SOLUTION
De-grease bath temperature too low

De-grease bath temperature too low

Increase the bath temperature

Increase the bath temperature

Pressure too high

Pressure too high

Check for plugged nozzles

Check for plugged nozzles

Pumps picking up air

Pumps picking up air

Check pump packing, check water level

Check pump packing, check water level