Corrosion on copper pipe

We have no leaks, so is this a problem? What causes this? See attached photos.

Plumber/installer of the copper piping didn't wipe the joints down after soldering. A piss-poor bad habit of the trade.


Hey, that's my back yard out that window. How you doing Mike?

Could it be you two are actually neighbors?

Least you could have done was wipe your joints when you helped out your neighbour, Rugged! Just a joke, now.

Damn, I'm busted

Blame it on the beer, all 23 cans of them.

Found the 24th can in my fridge!

Whoa......I wondered where all those empty cans came from. I knocked 'em all over when I tripped on the empty wine bottles I left behind! All those brain cells, shot to hell. No wonder I flunked American Geography! I only just found out that Brier (Washington), which is just north of Seattle (Washington), is a suburb of Northern KY and Cincinnati!

And now that you mention it, I always thought it was a good idea to wipe off your joint after installing your pipe. You've just confirmed my suspicions, and I thank you good sir.

But seriously, is it a problem, for like, the future well being of my pipes? Can the corrosion become a conduit for pinhole creationism? Should I consider replacing said sections, or simply bust out the naval jelly and steel wool and call 'er good? Inquiring minds want to know.........

Mike (in Brier) (Washington)

For the most part, no. That patina effect you see is a reaction of flux on copper and I've never seen it go as far as putting holes in it. It "can" though with big globs of it inside the pipe with numerous years of water passing over it trying to diminish the amount.

What makes it horrible is the fact that if you try to cut that pipe and install fittings......it makes it very hard to clean the pipe to get a new fitting to take.

Sand cloth on the pipe, using flux again and brushing the pipe with a flux brush while it's hot will remove it faster.....along with other preferred methods not involving heat of a torch.

Beer-thirty, gotta go!