I hope you don't mind my adding my two cents, but for what its worth the only thing water tells you about the surface is how "Polar" it is, as has already been mentioned. If the water spreads over the surface without breaking up into droplets, one can assume that whatever is on the surface is extremely polar. Copper is considered very hydrophobic in the printing industry as they use it for printing plates in lithography (oil based inks). Clean copper is very hydrophillic for a short period of time and then it will pick up whatever is in the atmosphere (the room that its in or associated with). A misleading reaction to water spreading is caused by chemical and/or mechanical cleaning which roughens the surface sufficiently to allow water to spread. This roughening also allows adhesives to adhere better due to the increased surface area, but you can still have contaminants on the surface.