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Cracking

Definition

Cracks of various lengths and depths.

Rissbildung

Causes

  1. Incompatible paint system used on thermoplastic substrates (direct use of polyester body fillers/ fillers, wash primers/ synthetic resin products on TPA), causing the TPA surface to soften
  2. Refinished paintwork insufficiently cured (too little or no hardener used)
  3. Inappropriate paint system used:
    Wash primer overcoated with polyester products
    Synthetic resin or nitro-cellulose paints overcoated too early
  4. Cracks on plastic parts:
  5. see entry on ‘Faults in painting plastics’
  6. Exposure to strong UV radiation, extreme temperature fluctuations
  7. Flash-off time too short in wet-on-wet process
  8. Total film build too high
Rissbildung
2 x magnification
  1. Apply a suitable paint system to the substrate
  2. Ensure correct hardener quantities
  3. Use correct paint system
  4. Plasticise materials (see entry on ‘Faults in painting plastics’)
  5. There are no complaints about cracking relating to current Glasurit automotive refinish products.
  6. Respect recommended flash-off times
  7. Check paint system and film thickness of old paintwork and sand down or strip down, if necessary

Please note: For older car models, use refinishing processes for solvent-sensitive paintwork. Classic Car system S 1a.

REPAIR

Sand down to the sound layers. Refinish using the recommended undercoats and topcoats.