What type of sandpaper is recommended for scuff sanding the surface of radar absorbing materials to ensure primer adhesion?

For scuff sanding the surface of radar absorbing materials to ensure primer adhesion, medium to fine grade sandpaper is recommended. This grade allows for sufficient abrasion of the surface without damaging the radar absorbing material itself. The medium to fine grade effectively creates a texture that helps the primer adhere better, promoting a strong bond between the primer and the radar absorbing surface.

Using coarser grades may remove too much material or create deep scratches, potentially compromising the effectiveness of the radar absorbing properties. Extra fine grades, while they may smooth the surface, do not provide the necessary texture for adequate primer adhesion. Heavy-duty grades are typically too abrasive and can be too aggressive for this specific application, risking damage to the delicate materials involved. Therefore, medium to fine grade is the best choice to balance effective scuffing while maintaining the integrity of the radar absorbing surface.