Possible Clues:

• Accumulate on a surface
• Gather on a surface, in chemistry
• Condense on a surface
• Gather on the surface, chemically
• Accumulate on the surface of rough boards
• Accumulate on the surface, like molecules
• Road's ruined: bumps initially accumulate on the surface
• On the surface of it, hold onto film for father returning to Rob¿s disaster
• Accumulate gases on the surface
• Hold film of gas or liquid molecules on surface