Marking edges (mapping)

Cause

• Incorrect ratio of hardeners and thinners in materials
• Layers of materials too thick
• Material not hardened enough
• The zone of transition of old materials sanded too little

Countermeasure

• Do the thinner test
• Insulate the repaired surface with a primer e.g. epoxy in thin layers
• Remove old, damaged layers up to bare steel

Removal

• Sand, insulate and then varnish again