no. the problem with soldering is not high current, it is the mechanical stiffening which means that its very likely to fracture where the solder stops..
no. the problem with soldering is not high current, it is the mechanical stiffening which means that its very likely to fracture where the solder stops..
No that's cupric oxide.
Or at lest let'ssay there are two copper oxides, one red, one black, and both may be referred to as copper oxide. Cuprous is the red one. Cupric is the black one.
copper carbonate. Co2 in the air in the presence of water turns copper oxides to copper carbonates. Theres a few more copper salts that pop up too sulphates and acetates - any weak acid will turn the oxide to a salt eventually.
A 6" spring to sheath the finished joint might be better. If one can stop it sliding out of position.
At our old house where the copper CH pipes went into the floor (concrete) the pipes were stained green about a half-inch above the cement. Why would it be occurring just there?
Dunno off hand. Mortar can be quite alkaline, and I would guess that it's something to do with the alkalinity of the cement coupled with straightforward oxidation of the copper. I've seen similar sort of thing when solder flux is also involved, and I believe it's now good practice to wrap all soldered joints in copper pipes with something like Denso tape if they're going to be buried in concrete.
Having said all that, Googling for 'concrete attack copper' gives a variety of answers, many of them saying that copper isn't attacked by concrete.
Well actually copper pipe buried in concrete is attacked, but not chemically, it's a physical effect. The ch pipes expand and contract as they warm and cool, and the copper is abraded by the concrete. This is why the advice is to sleeve the pipe before pouring the concrete.
AWEM
And see all that Southern Railway rolling stock in malachite green. :-)
best place for condensation.
Inspiring! I'm now on ebay trying to source a malachite coloured roller-neck jumper and some bright red flares to set it off.
...and copper melts at 1085 deg C
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