OTHER DEFECTS

BAD LEVELLING

Causes:

  • Unsuitable (too high) viscosity.
  • Unsuitable application technique.
  • Unsuitable working temperature.
  • Use of unsuitable THINNER.
  • Unsuitable spray gun (nozzle), pressure.

Prevention:

  • Follow technical instructions for use – viscosity and temperature.
  • Use of prescribed spray gun (nozzle).
  • Use of prescribed THINNER.

Repair of incurred defect:

  • Sand to filler and repeat painting of top coat as prescribed.

SAGGING

Causes:

  • Unsuitable viscosity of MOBIHEL Base.
  • Too high thickness of MOBIHEL Base.
  • Unsuitable spray gun (nozzle), pressure.
  • Too cold material, surface or too low room temperature.
  • Use of unsuitable hardener or thinner.

Prevention:

  • Follow technical instructions for use.
  • Use a suitable spray gun.
  • Warm the object and material to room temperature +20 °C.
  • Use of a recommended hardener and thinner.

Repair of incurred defect:

  • Sand to filler and repeat painting of Base as prescribed. If a “flow” is big, sand it with paper of granulation 600, continue with 1200 and the end with 2000. If the “flow” is not big, sand it with paper of granulation 1200 and at the end with 2000. In both cases, you have to polish the surface at the end.

CRATERS

Causes:

  • Wax, grease, silicone contaminated surface.
  • Compressed air contaminated through condensed air or oil residue.
  • Use of silicone, polishing agents or sprays in the vicinity of painting area.
  • Insufficiently cleaned surface before coating.

Prevention:

  • Before starting painting, clean thoroughly with MOBIHEL Antisilicone cleaner low VOC.
  • Regular maintenance of oil and water separators (filters).

Repair of incurred defect:

  • Sand to filler and repeat painting of topcoat as prescribed.

POPPING

Causes:

  • Incorrectly dried-through filler.
  • trapping of solvents and air because of too high film thickness.
  • No flash off between coats.
  • Wrong HARDENER and THINNER.
  • Interrupted drying (not following drying time).

Prevention:

  • Apply the prescribed coat thickness.
  • Wait between the first and the second coat 10 – 15 min. /20 °C or until mark-free surface.
  • Regular check of activation and temperature of a drier.
  • Follow prescribed flash off times between coats and final flash off.
  • Use the prescribed HARDENER and THINNER.

Repair of incurred defect:

  • Sand to sheet metal and repeat painting of top coat.

MATT EFFECT (GLOSS DECREASE)

Causes:

  • Too high coat thickness MOBIHEL 2K HS 2:1 clearcoat (more than 2 coats) - too high air humidity.
  • Surface soaking.
  • Hardener defects – hardener reacted with air humidity.
  • Humidity in compressed air supply.
  • Use of unsuitable thinner.
  • Unsuitable air supply.
  • Interrupted drying.
  • No MOBIHEL Siccative added into 1K synthetic enamel (MOBIHEL enamel MIX).

Prevention:

  • Follow technical instructions for the application of material.
  • Keep hardener cans sealed properly.
  • Enable sufficient airflow (during drying).
  • Do not interrupt forced drying.
  • Follow prescribed drying times.
  • Use recommended hardener and thinner.
  • When mixing MOBIHEL enamel – mix according to formulation at the end obligatory add MOBIHEL Siccative.
  • With the 1K synthetic enamels (MOBIHEL enamel) take care of overcoating times in order to
    prevent surface soaking.

Repair of incurred defect:

  • Sand to the sealer and repeat the application of MOBIHEL 2K HS 2:1 clearcoat according to regulations.
  • Check the quality of a hardener – it should be clear, colourless, fluently running, without any floating particles.

SANDY SURFACE

Causes:

  • Isocyanate HARDENER for 2K materials reacted with air humidity.

Prevention:

  • Use up open packaging of isocyanate hardener as soo as possible or close it tightly.
  • Check quality of a hardener before repeated use – it should be clear, colourless, fluently running, without any floating particles.

Repair of incurred defect:

  • Sand to filler and repeat painting of top coat.