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harry harry is offline
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Default Green Sludge In Plumbing?

On May 9, 5:14�pm, DerbyDad03 wrote:
I was doing a little plumbing yesterday and came across something I
hadn't seen before.

I cut a 1/2 copper pipe about a half inch from a sweated copper
coupling. Inside the pipe was small amount of green sludge, almost
like a drip, about 3/4" long. The sludge was soft and easily removed
from the pipe.

Was this nothing more than some flux that had seeped onto the joint
and reacted with the copper?


This is copper carbonate. It's caused when dissolved CO2 in the water
makes it acid and it attacks the copper. This is why copper clad
roofs turn green. It doesn't help if residues of acid flux are left
in the pipe from when it was soldered. In the UK modern fluxes are
water soluble and flush away, years ago they didn't. They done away
with lead based solders too at the same time. Dunno about America,
probably the same.
Copper oxide BTW is red or black.
http://en.wikipedia.org/wiki/Copper_carbonate