In an attempt to figure out why I keep getting white bits floating in my Conti's reservoir even with new, distilled water, I discovered this:



Note the fluffy white bits that look almost like mold. I had just used Cleancaf to de-scale the reservoir, having found white bits in there beforehand:



The base material is, I believe, aluminum—or aluminium for our Brit cousins. The white fluff began to develop mere hours after cleaning and thorough rinsing, and appears to be slowing increasing. Two days later and more is there.

Does anyone know what the white stuff is and, more important, how to get rid of it?

Thanks!

SWAG,
I am unable to find from advertising product descriptions whether Cleancaf is a hydroxide or phosphate cleaner. If the label reads "contains .. TriSodium Phosphate or phosphate or hydroxide/lye" those cleaners will eat aluminum. They are great for removing greasy dirt.
The "Material Safety Data Sheet" says that it contains phosphorous compounds:
Click Here
The phosphates are called by jawbreaker names in the US section. Look under "EU. Labeling" on the second page, bottom, of the document. They call the chemicals by simple names. Like "TriSodiumPhosphate with the words rearranged.
If a basic cleaner ( non-acid,) rinse with a dilute acid like vinegar or citric.
Rinse very well with clear water afterward.
An aluminum boiler does not take well to a basic cleaner. There are cleaners for such machines.
Looking at a sales site, It is listed as a cleaner and de-scaler.They do not warn against its use for aluminum. I find that Cleancaf is not recommended for some other metals though.
That's my best answer with the little chemistry I know.
Good luck, You asked in time!
-Richard

One curiosity over this rapid formation of some precipitate would be to change the water source, say using distilled water to see if this happens, or even check the pH of your water or check the total dissolved solids before and after...much the science experiment. The original treatment to clean that boiler element and plate (and indeed it originally resembled a solid piece of chalk) was to soak in citric acid, brush and rinse, soak again, brush and rinse, and finally picking out all of the remaining scale, which I am assuming is a calcium compound, calcium carbonate perhaps? It seems that some amount of scale on the aluminium serves a protective function of sorts against corrosion of the metal, just my theory with no substantive evidence.

Perhaps the zealous cleaning provided a fresh substrate for the formation of these white deposits.

Besides doing some experiments with different water, maybe continued rinsing as the precipitate develops will eventually get rid of the problem, without the addition of new chemical treatment. Most strange though.

hello
another assumption for me that of chemistry. that of l' electrolyse between two metals when there is l' electricity not far. you have an earthing in your house? is the structure of the machine well connected has your installation?
best regard

Here's another guess from another non-chemist: the white fluffy stuff looks like aluminum hydroxide to me. Normally, aluminum forms an unreactive film of the oxide on its surface, preventing further reaction. If your water supply is alkaline (high pH), I think it interferes with the film, or dissolves it, and then it's quite likely that it would form the hydroxide (hydrated oxide, actually) which is fluffy and gelatinous.

Unfortunately, I don't know how to stop it, nor am I all that confident in my diagnosis. Why not inquire directly of Conti and see what they say?

Sorry for the belated response. I teach for a living and literally get almost no free time during the day, so any research on this phenomenon has been s l o w. I've been ill and took the day off, thus the post.

I left water in the reservoir for a few days after the previous pictures and the white growths continued to... Grow. I emptied it and white reside was left, similar to the prior picture but much more of it.

I haven't gotten any responses from retailers about low-base cleaners and citric acid. I had a bottle of Durgol, though, so I tried it today. First a little bit, then the rest of the bottle. Here are the results:



For the second attempt, I left Durgol in the reservoir for ten minutes. It appears to have worked off a fair amount of whatever this white stuff is. It was significantly worse before I tried, and when I dumped the Durgol it was still actively bubbling away. I need get some more Durgol, so I might try it again but for a longer time period.

I have not yet tested my water hardness, but Atlanta is notorious for hard water. That said, I switched to distilled water when I first noticed white bits floating around a few months ago. Didn't notice much change, but I had not yet taken off the heating element cover. The growths came on like mad only after I used Cleancaf. I do have some Cafiza, but I suppose that is just as bad as Cleancaf.

I will leave distilled water in the reservoir to see what happens. Any further ideas or suggestions?

FWW
Channo said something about electrolysis of the dissimilar metals. That could be a key. Some of the Peppinas came with a little ¼"wide ½mm ( .020") zinc band around the heating element near the wet end entrance to the reservoir/kettle. That was to sacrifice itself to prevent Galvanic corrosion. Maybe that could be a possibility for you. Some print shops have used Zinc plates which would be a very pure zinc. An old "Ball" brand zinc & glass jar cover would work. Cut a strip around the skirt and wrap it around one end of the element. Antique store and a couple bucks might do it..
Cheers
-Richard

I realize that everyone in the world must be tired from sitting on the edge of their collective seats waiting for my latest installment, so here it is.

Two weeks ago I cleaned the Conti with Dezcal followed by a bath of Durgol, since the latter seems milder than the former. I should note that neither got rid of the white growths, but I wanted to start anew. I then placed little zinc bits (all that I could get from my school's science department) on the bottom plate, making sure to let some pieces touch both the heating element and aluminum base. Within maybe four hours the white growths diminished: Within one day they seemed to disappear. After three days the color of the aluminum was visibly lighter.

I let everything sit untouched for two weeks, which brings us to today. Some very minor white stuff was beginning to form on the inside portion of the base where water enters the cylinder while drawing shots, so I physically rubbed them off, cleared everything out with water, and tried a shot. I had not used the Conti for more than a month, so I ran about one litre of water through first. Definitely missing a previously unpleasant edge. The water in the reservoir has been significantly clearer than before, too. I replaced some of the zinc bits and will try to track down a larger piece to leave in permanently. In short, it appears the problem was indeed electrolysis-induced and it seems as though zinc fixes it.

I do wonder, though, if there might be any health-related issues by leaving zinc in the reservoir. In small amounts, it should not be a problem. I think. Can anyone provide a more informed opinion on this?

P.S.
I should note that I tested my tap water and it did not even register on the hardness test strip.

Hi Danno, was just wondering how you were doing - Spring Break & all! Good news on the Zinc, my totally unscientific, and unsupported opinion is that it probably wouldn't hurt you - zinc is one of the minerals that you are supposed to have in your daily diet...

The only Zinc I can think of right off hand, Richard already mentioned - zinc caps for vintage ball fruit jars (sometimes you can find new old stock ones in antiques stores or on ebay) - too bad, I used to have dozens of them, from collecting Fruit Jars in my acquisitive youth...all gone now.

Just checked - McMaster has some corrosion inhibiting zinc rods & pads - the smallest rod is 3" x 3/8" diameter...

http://www.zinc.org/zinc_health.html

From your friends at the American Zinc Association (or something like that).