Which method is improper for removing paint from composite surfaces?

High-pressure water blasting is not suitable for removing paint from composite surfaces due to the potential for damage to the material. Composites are often made from layers of different materials bonded together, and using high pressure can compromise the structural integrity or delaminate these layers. Additionally, water can seep into areas that are not sealed, leading to future deterioration or weakening of the composite.

In contrast, methods like orbital sanding, hand sanding, and the use of chemical strippers can be more controlled and gentle on composite surfaces. Orbital sanding and hand sanding allow for precision in the removal process, reducing the risk of damage. Chemical strippers can safely dissolve paint without the mechanical stress that sanding introduces, though they must be used carefully to avoid harming the underlying composite material.