[e_engineer]

a really fine dust might stick via static electricity.

Opposite charges attract each other, but once they touch, the charges neutralize. If there is still a net charge after they touch, the particles then repel one another. (Like charges repel).

[Frank_Discussion]

I've seen dust stick like that to a surface, but perhaps it would not stick to itself via static, based on what you're saying. I'm starting to think I jumped the gun here...