Question

2. Why does old car bumper change colour?​

Answer 1

Answer :

This is because the evaporation rate for solvent varies between metal and plastic surfaces. Plastic holds heat for longer than metal does, which means the paint takes longer to dry. The longer the solvent takes to evaporate, the longer the metal flakes within the paint has to 'float' and this can darken the colour.Aug 15, 2016