Found a Home Barista thread with a similar issue - http://www.home-barista.com/espresso-machines/copper-brass-oxidation-t10066.html
I believe it's just my non-copper (brass and chrome-plated brass) metal components being electroplated with copper. Similar to what's happening here<http://www.hometrainingtools.com/electroplating-science-project/a/1769/>. It doesn't seem like it even requires electricity<http://www.homemodelenginemachinist.com/f25/home-copper-plating-steel-without-electricity-1740s-recipe-2834/>! That said, there might be a small current running through the water/solution because that's how the level sensor works? Thoughts? On Tue, Jun 11, 2013 at 3:55 PM, Anthony Yim <[email protected]> wrote: > Hi everyone, > > This is my first post to the group. Nice to meet you all. Looking forward > to learning a lot about the Brewtus and espresso from you guys! > > *Summary:* > I recently bought a relatively unused Expobar Brewtus II from a little > cafe in upstate NY. Previous owner claimed it was only lightly used and > performing the e61 group mushroom > inspection<http://www.frcndigital.com/coffee/HowToE61overhaul.html>shows > little scale (first two images > here <http://imgur.com/a/bIlID>). > I decided that I should descale the machine anyway despite light usage so > I can start fresh/clean. After following a fairly standard set of descale > procedure* with some slight modifications, I proceeded to purge the > machine of descale solution. The solution came out slightly green through > both the brew group and the hot water wand (as expected). I then proceeded > to remove the mushroom so check it out and also pour any remaining solution > in the brew boiler out (as per Dan Hagelin's comment on > this<https://groups.google.com/forum/#!msg/brewtus/Etc06jUJ7E0/AEtm4dF8WokJ>thread). > I immediately noticed that a) there was a lot of copper flakes in > the solution in the mushroom and b) lots of components in the group changed > color (you can see what I'm talking about in the 3rd photo onwards > here<http://imgur.com/a/bIlID>). > Furthermore, pouring the solution out of the brew boiler via the now > disassembled mushroom reveals copper flakes coming out (like > this<http://coffeetime.wikidot.com/metal-flakes-after-descaling>). > It appears that I'm not the only one experiencing this. > > *Concerns/Questions:* > Even though it seems that seeing copper flakes is "normal", I'm still a) > concerned about its health effects and b) curious what exactly happened. > Especially when I know the group components (with the exception of the cam) > are brass and the color change that resulted after descale is that of > copper. I might have left descale solution in the machine for too long but > my understanding is that citric acid is still quite weak as an acid and > don't except I'm able to do a ton of damage. Can anyone shed light on what > happened? > > Thanks! > > Best Regards, > Your concerned Brewtus newbie - Anthony > > *My descale procedure: > 1. Empty steam boiler (by letting it all out via hotwater wand while it's > at temp) and brew boiler (by disassembling mushroom and turning machine > upside-down) of water. > 2. Mixed Dezcal solution according to package directions (1L water for 1oz > of Dezcal). > 3. Ran enough Dezcal solution into machine via water intake hose until > both boilers are full of solution. > 4. Turned machine off and waited for 1 hour. > 5. Turned machine on and let it get to full temp for 1 hour. > 6. Empty boilers via same method specified at step 1. above. > > -- > You received this message because you are subscribed to a topic in the > Google Groups "Brewtus" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/brewtus/FHO-LxTUOic/unsubscribe?hl=en. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/brewtus?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "Brewtus" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/brewtus?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
