Troubleshooting

Troubleshooting

Some questions have come up more than once, and are likely to come up again. Here we'll post questions that we hear from time to time, hopefully one or more of these will save you some time and effort. Please click on a question to show possible solutions.

Coat too thin. Impossible to increase thickness.

Possible Solution

  • Increase voltage, increase fluidization, increase powder feed.
  • Check resistance (ohm) between two different supports/objects on conveyor. Ideal film reading is 0 ohm.
  • Check earth connection from conveyor and outward.
  • Check spraying equipment, fuses, voltage, electrodes in gun mouth, all electrical connections to high tension cable.
  • Check powder by using another powder spray gun.
Thin or no coat at support hooks.

Possible Solution

  • Problem due to poor earth connection and should be investigated
Poor flow - orange peel effect.

Possible Solution

  • Increase fluidization from spray gun.
  • If possible, reduce voltage.
  • Use fastest possible heating cycle in oven.
  • Adjust film thickness to give best possible appearance.
  • Check optimum distance between object and gun mouth.
  • Problem may be due to poor earth connection.
Different powder outputs from guns.

Possible Solution

  • Different hose lengths between powder feed and gun.
  • Air pressure too low.
  • Ejector fault, or partial blocking of ejector, hose and gun.
Gun sputters.

Possible Solution

  • Adjust atomization air.
  • Replace hoses between powder feed and gun. Alternatively replace with hoses of smaller bore.
  • Check that compressed air is free of water and oil.
Yellow or brown spots or stripes on the final coat.

Possible Solution

  • Poor cleaning.
  • Residues of cleaning agent (moisture).
  • Check that compressed air is free of water and oil.
  • If cloths used for wiping, check if suitable for the use.
Craters-full depth.

Possible Solution

  • Indicate contamination of object prior to coating.
  • Check whether water based paint (acryl) has been used nearby.
  • Check whether there is silicon in any materials / lubricants etc. Often used when welding.
Craters - fish eyes.

Possible Solution

  • Usually indicate contamination of the powder, though may also indicate contamination of object.
  • Check that compressed air is free of water and oil.
  • Check that powder is free of craters when using another spraygun or by melting powder on a plate.
  • Test the powder coat of other objects.
Curing.

Possible Solution

  • Check that all thermostats are working properly.
  • If possible check metal temperature using temperature recorder.
  • Check air circulation.
  • When all above points are functioning properly, increase or decrease the conveyor speed until hardening is correct.
No powder from gun.

Possible Solution

  • Check all fuses.
  • Check compressed air.
  • Blow through pneumatic system with air gun.
Particles/dirt in powder coat film.

Possible Solution

  • Check that product is completely clean before coating.
  • Prevent dust from entering spray box. Remember that all air borne dust particles can enter the spray booth due to air flow through the booth.
  • Sieve powder and examine residue in sieve.