Found some copper plumbing supply pipes in the crawl that were black as can be. Not just faintly, but chinese drywall black. These were only observed in the crawlspace. The crawlspace did have some excessive moisture and ground water issues.
The pipes all seemed to be in good order and the home was built in 92.
Any ideas??
Hi Sean;
There is a variety of things that could cause black copper pipes.
A few causes would be;
sulfer dioxide
methamphetmine manufacturing
sewer gases
exessive moisute (sweating)
various chemical compounds such as pool acid, chlorine etc.
Electrolysis (low electrical currents going through the copper lines)
That would be my bet in a crawl space. Check with an AC voltage meter ground to pipes.
Hope that helps with what you saw. 2+2= 4 hopefully. :)
Country home? Probably sulfur water. See it here all the time. Turns wires & everything black/corrodes.
MY guess would be the ground water issue and sulfur. The home had some major issues with a wet crawl, and no real reason for it outside around the home.
I never checked the current deal, but the plumbing was bonded.
But where would the sulfur be coming from in the crawl? 
The stinky ground water that was filling it up. 
Just comment in the report as such: “The copper pipes in the crawlspace have successfully reached a rich and deep patina.”
Venting from the bathroom terminating in the crawl??? :mrgreen:
If you don’t know…say you don’t know. So far all you got are guesses.
Gees you sell antiques I bet;)
Many design studio reviews in architecture when you had to present your buildings to a group of stuffy professors.
Of course Cameron. I was just making light of a word commonly used explaining a material mostly metal that has changed colour; “patina”.
The reason for the patina that is most accentual.
All within 3 junctions of the hot water tank.
Only at the elbows intersection.
Greasy like Bryl Cream. Hope I am not giving away my age.
I hypothesized flux. I sweet copper plumbing and used flux when I work with tin smiths on copper and galvanized with 50/50. etc. Normal in the late 1070’s.
The question why.
Henceforth this is why plumbers MUST wipe the fitting/s clean after a solider or glue-up… Its the signature of a job well done. Pressurization or load being the last test;)
The apprentice will review all work as the plumber moves on. By catching any anomalies you are stroked with advancement if there are men behind you as they work there way up the ladder to license.( If they wish) Many settle down to a regular pay check or so I have seen.
PS: I have also dabble in antiques.
The corrosion and hard water deposit in that picture was caused by a leak.
I agree.
What caused the leak?
Several fittings had suspect plumbers flux. Your could feel it on all the effected pipes.
Am I mistaken about the greasy compound.?
I have sweat enough copper and soldered galvanized and copper seams for roofing.
I also know the flux evaporates when heated.
1.I know a leak leaves the same observational evidence.
I feel for moisture and look for any evidence of staining, liquid,
Staines underneath on surfaces, even use a tissue to see if if will wick any moisture.
2.Previous elbows with leakage staining “the same in appearance” not in physical evidence.
On the pipe upstream had pasty fell only no darkening.
Some help would be greatly appreciated.
Without a laboratory test of the waxy greasy like substance you are left perplexed.
Owner mention maintenance. He is a flipper or investor.
Leak, just like this one here;
Help much appreciated Marcel…
I felt the visible scaling for moisture, As usual.
It appeared to have a uncommon appearance, a shine like nothing encountered before.
It had a greasy texture. I know it was a leak but from what?
The piping after the joint had a flux tackiness. You know plumbing Marcel its unmistakable.
next time, if there is one I will write what I see not feel.
In my report.
SUSPECT: Active leaks, reinstall hot water tank plumbing…