Mechanical damage to the coating due to projected small stones/chippings (e.g., loose gravel).
Causes
Stones are flung onto the paintwork at varying levels of energy (velocity/size). Depending on the impact force, the top layers and also the lower paint layers underneath can be damaged down to the substrate. At the points of damage, humidity will penetrate the coating and lead to corrosion creepback and flaking.
How to avoid
There is no total protection against stone chips. Areas most greatly at risk can be given preventive treatment of additional stone chip and underbody protection (Stone Chip and Underbody Protection black) and/or the use of Softface Additive. An extremely scratch-resistant clearcoat offers protection against small stone chips.
Repair
Stone chips should be touched-up immediately. Refinish using the recommended undercoats and/or topcoats.