I recently went into the crawl space under the house. I was horrified to find that the plumber never cleaned off the joints after soldering them. Two tell tale clues: green stuff on all of the joints AND solidifed solder drips under the joints. I know that this flux can corrode the copper. So far, no evidence of pin-hole leaks. I have been advised to use a wire brush to clean off the joints. My question(S):

Do I need to use some type of cleaner after using the wire brush?

Is it too late? (This house was built in the summer of 2001).

Thank you

Simply wire brush the old flux off and squirt a little oil around the joiint to neutralize the acid. Good luck, Tom

Flux would melt off the solder joints when soldered leave it alone should not be a problum

Why " I was horrified " about this? Do you solder much yourself, its no big deal, you are fine.

I agree with the original poster. Flux in the crawl space invites corrosion. Problem is, the flus becomes very difficult to remove.

You could use a commercial spray such as these: flux remover

Or Hot water and baking soda. As warm as you can get it and handle with gloves.

A wire brush does nothing with flux. It will remove the existing corrosion, but it just spreads the flux.

So, two options:
1) commercial spray flux remover
2) Baking soda and hot water mixture

As suggested, use Wire Brush, Steel Wool, Sand Cloth, Mesh Cloth or sandpaper to remove corrosion caused by the left-over flux. The flux itself will go away easily when heated up a bit. Even scrub pad used for pots and pans dipped in hot water may do the trick

Shock I would be not. It does happen. We see it all over... especially with the "discount plumbers". You save few bucks but...