Weepy copper joint

While soldering a new T into an existing copper pipe, I inadvertently heated a nearby joint to the point the solder was bubbling. now the joint weeps a little water. How little? When I rub my finger in gypsum dust and then rub the joint, it comes back damp. It doesn't drip, nor even run down the pipe, although some copper oxide is beginning to accumulate. I've kept the wall open for a couple months, hoping that calcification and oxidation would stop the weep, no luck. There are a number of other Ts nearby, and I'm afraid that attempting to reheat the joint will only make things worse. Should I: 1-Attempt to resolder? 2-Clean the joint and wrap it in epoxy? 3-Close the wall and hope it never becomes an issue? 4-Attempt some other fix which you will advise me of presently?

You only have one option and you know which one it is.

You can wrap a wet cloth around the nearby joints to keep them from getting hot enough to do that. You need to pull apart that leaking one, clean it off, flux, then resolder it. Sometimes, it easier to just replace the joint.

New England and Canada, therefore you are living in those magic kingdoms where the pipe is solid and most of the plumbing is above ground. Now, imagine you are in California and the repairs you are proposing are to copper tubing four inches above where it disappears under the slab and are very likely going to entail moving a wall and jack hammering the slab.

Are you sure it's not condensation, but actually leaking from the joint?

If so, as is posted above already, you really have to take it off and redo the joint.

Not sure of your concern about the pipe going into the slab or why you'd have to jackhammer concrete or move a wall - post a picture if you want some feedback about that.

It's always a lot more work to do things the right way, isn't it?