1. Decayed old paint
2. Old paint is acrylic lacquer-based
3. Using the Thinner which is too strong
1. If existing paint is decayed, sand off or spray over with a slow-drying primer (Urethane).
2. Use the Thinner which is compatible with paint type
1. After the surface has dried, sand down, spray the primer and refinish.
2. Remove the paint and refinish