What is a major disadvantage of using steel brushes on aluminum surfaces?

Using steel brushes on aluminum surfaces can indeed lead to significant issues, primarily due to the potential for corrosion from embedded steel particles. When steel bristles come into contact with aluminum, small particles can become lodged in the softer aluminum surface. This is problematic because aluminum is prone to galvanic corrosion when it comes into contact with dissimilar metals, such as steel. If moisture is present, the steel particles can create electrochemical reactions that lead to corrosion of the aluminum, compromising its structural integrity and longevity.

This highlights the importance of choosing the appropriate cleaning tools for specific materials, especially in aviation where the integrity of components is vital for safety and performance. It's advisable to use non-metallic brushes, such as nylon pads, which do not pose the same risk of contamination or corrosion when cleaning aluminum surfaces.