I'm installing a new vanity and found green oxidation at the elbow joints of the copper pipes exiting the wall. As you can see in the pictures below, there is much more oxidation on the hot water pipe (first two pics) than the cold water pipe (third pic).
I recently purchased the home and don't know the history of this plumbing. Nor do I know much about plumbing, but it looks to me like the soldering on the joints may be newer than the oxidation. If so, perhaps those joints were previously leaking and then repaired, so nothing more than perhaps a good cleaning is in order?
Or does the amount of patina suggest that I need to remove/replace one or both pipe sections?
Thanks in advance for any help.