Copper / Brass Oxidation?

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yooncs

#1: Post by yooncs »

Hello all,

My first post on the forum!

Here is what I see when I disconnect internals of my Oscar. All the copper pipes and internals are all rather pink(?). Is this normal / safe? Is there ways to turn these back to what they were?

Thanks,
Chong


decaf_Ed

#2: Post by decaf_Ed »

My first guess would be that what you're seeing is the color of the minerals in your water. If you see the same color around faucets, bathtub spout, etc., then this is a likely explanation.
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danetrainer

#3: Post by danetrainer »

yooncs wrote:Hello all,

My first post on the forum!

Here is what I see when I disconnect internals of my Oscar. All the copper pipes and internals are all rather pink(?). Is this normal / safe? Is there ways to turn these back to what they were?
Hi Chong, welcome to HB!

You can clean those items up by soaking them in a citric acid solution...there are links to give you more information about cleaning/descaling in the resources and the faq section such as the following:

Espresso Machine Cleaning - Why, How, and When
Water, Scaling and Descaling with HX machines?

Once clean you will want to use a water filter in line, or, if your Oscar is a pour-over model (like mine was) you should simply fill the tank with filtered water when using it from now on. There is allot more info on that too, because if it doesn't have enough mineral content in the water the tank sensor will not operate properly and it will think it is empty.

Best of Luck and Enjoy!

Pat

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narc

#4: Post by narc »

Copper oxidation is usually the blue green patina color you see on copper roofs and old pennies sitting in wishing ponds. Do you have a high iron content in the water situation? Some of the people up where I live pull up real ultra fine sandstone sediments that is high in iron in the well water. Their inline filters to the household water supplies end up with a similar color to your espresso machine parts.
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jasonmolinari

#5: Post by jasonmolinari »

I recently descales my machine, and took out the mushroom from my E61, and everything on the inside was this color. Don't know what it is or why

Jeepin' Geo

#6: Post by Jeepin' Geo »

Chong,

After soaking the boiler pieces of my Silvia in a strong citric acid solution, all the water contact areas turned that pinkish color. Prior to the soaking those areas were blackish. The non-water contact areas remained the original color.

I recall reading an explanation of the reaction somewhere, but don't recall the details! :oops:

George


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GVDub

#7: Post by GVDub »

According to this article, early stage copper oxide is pink. It darkens later.
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yooncs (original poster)

#8: Post by yooncs (original poster) »

Thanks for the replies. :D

I bought it used, so I am not sure about the condition of the water it was running through.

However, I think I found what caused it (hints from Jason and George) but not sure about how safe / stable it is and how to turn back to the original condition.

I was using descaler from partsguru, and it must be too strong or contain something other than citric acid? I soaked copper and brass parts with stainless steel parts together, and after a while copper parts turned reddish / pinkish and stainless parts turned copper color as if it was coated with thin copper layer. :cry:

I am having very limited success with copper cleaner which can be purchased from regular super market but by not much. I am especially concerned about how to clean up inside tubes..

Any suggestions?

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itsallaroundyou

#9: Post by itsallaroundyou »

GVDub wrote:According to this article, early stage copper oxide is pink. It darkens later.
that's the difference between its oxidation states, explained here:

http://en.wikipedia.org/wiki/Copper(I)_oxide

and here:

http://en.wikipedia.org/wiki/Copper(II)_oxide
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timo888

#10: Post by timo888 »

Acid (e.g. from descaling solutions) causes copper to turn pink, as Jeepin' Geo described. The pink is not a problem. Using additional chemicals could be, though. Potable water passes through those tubes.