# Old La Pavoni: Black Stuff inside the pick-up tube



## BigBadWolf (Sep 28, 2014)

Hi!

I bought a very old and battered, rusty and scaly la Pavoni off ebay, and I'm currently restoring it - after extensive descaling, there is still a very thin *black* layer on the inside of the copper pick-up tube. Does anyone know what it is, and if it is bad? (My tip is fat from coffee, but I'm not sure if there's some kind of black copper oxide.)

The machine was made between 79 and 82 (it has a flange, but the base is not yet plastic). As far as I can tell, the pick-up tube is brass. There's also a thin black layer on the thread that gets screwed into the group.

Much obliged.


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## h1udd (Sep 1, 2015)

Copper oxide is black if thats any help


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## BigBadWolf (Sep 28, 2014)

Thanks! It does help.

I found something relevant in case anyone stumbles upon this thread:

http://www.fwr.org/copper.pdf

At page 23 under "Forming Protective Layers", it goes to show some really interesting points. In Waters of Ph > 8, a jet-black corrosion is formed, which protects copper from further corrosion, and is supposed to be the most protective. So I guess it's a good idea to use the Pavoni with very alkaline water until it gets a blackish patina? Would be interested if you (or anyone) knows if that's a smart thing to do.

Edit:

In the aforementioned paper, it's listed as a temporary measure to "heat shock" copper with water above 60°C to convert oxides into black copper oxide. So there's that.


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## Rhys (Dec 21, 2014)

Interesting stuff, although I only use bottled water with mine (Volvic) as I'm finding it lasts quite a while since there's no cooling flushes needed like on HX machines.


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