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My aluminum kitchen stuff keeps turning black from the dishwasher


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#1 jennifer

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Posted 11 October 2010 - 06:46 PM

Things that are aluminum are coming out of my dishwasher with a black powder layer on them, and the pieces are essentially ruined. My garlic press of 10+ years, ruined and in the garbage. The new sheet pan from the very nice new toaster oven, same thing, took it out of the dishwasher & now it’s got a black soot/dust layer that comes off when you touch it or wipe it or whatever. My H thinks Cascade did something different with the detergent. But this also happened years ago with my heavy-duty Chicago Metallic 9x13’s from Williams-Sonoma. Cascade’s box says “Now with Dawn”. Maybe that’s it? It’s phosphate free also, not sure if it’s always been that way or if that's something new and they’re adding other stuff in to make up for it?

Has anyone else experienced this or happen to know what's going on here?

#2 jennifer

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Posted 11 October 2010 - 06:58 PM

I just Googled this and found this thread where tons of people are having the same problem...aluminum cake pans, sheet pans, etc. turning soot black from the dishwasher. Some people say they've been putting their aluminum stuff in the dishwasher for years with no problem. Other's are having the same problem I'm having. Some people say restaurants hand-wash all their sheet pans, others say no way.

No where in the thread though, is a cause or solution. Bummer.

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#3 Calabrese

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Posted 11 October 2010 - 07:07 PM

I just Googled this and found this thread where tons of people are having the same problem...aluminum cake pans, sheet pans, etc. turning soot black from the dishwasher. Some people say they've been putting their aluminum stuff in the dishwasher for years with no problem. Other's are having the same problem I'm having. Some people say restaurants hand-wash all their sheet pans, others say no way.

No where in the thread though, is a cause or solution. Bummer.

http://community.coo...ad.php?t=125864



Here

http://www.thathomes...75625865.html?6

you will find this explanation:

"In the chemical reaction between soap and aluminum ATOMIC hydrogen is formed. Atomic hydrogen has a very weird property of actually being able to move completely through solid aluminum......because it is such a small particle. Atomic hydrogen cannot be contained in an aluminum vessel.....it moves right through it as though it weren't there. It remains in the atomic state only until it meets another atomic hydrogen atom which then produces the hydrogen molecule H2. Molecular H2, which is a gas, cannot pass through solid aluminum. This process of hydrogen going from the atomic form to the molecular form causes the metal to actually flake (sometimes even crack) helping produce the powdery residue that you saw. The hot water in the dishwasher greatly accelerated this reaction.Soak is OK to use on properly seasoned cast iron, but must be used with CAUTION on cast, or coated aluminum cookware. Soaking SCRATCHED Teflon coated aluminum cookware in soapy water will cause the Teflon to rapidly separate from the aluminum........but this another whole new thread onto itself too.

What I have just revealed is based on solid chemistry and science. I have dealt with this type corrosion mechanism on major industrial processing units in my former career.

Bottom line......don't wash aluminum cookware in a dishwasher. Don't soak your scratched coated aluminum cookware for too long either......leaving it soaking in soapy water will accelerate the deterioration of the coating. Don't soak cast aluminum either as it will cause pitting."




#4 gturillo

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Posted 11 October 2010 - 07:08 PM

Your H was correct, see what I found on Cascade's website:

Response from Cascade:By Monika, Cascade Consumer Care, August 12, 2010
I'm sorry your pots and pan turned black recently while using Cascade. I'm glad to hear you were able to remove it. Cascade is now phosphate-free, as required by new legislations across the whole industry. One benefit of Phosphates in dishwashing is its ability to help protect the surface of metals. With the removal of phosphates, discoloration on aluminum may now occur faster than before. You should always check the product labels and/or manufacturer of your pots and pans to make sure they are dishwasher safe before you clean them in your dishwasher. Some good news is that discoloration does not affect the food being cooked.

#5 jennifer

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Posted 11 October 2010 - 07:21 PM

I was just texting with my chemical-engineer friend and she said that phosphate free isn't an issue but extra soap (i.e. Cascade "Now with Dawn") and phosphate free would require longer rinsing for regular dishes and handwashing for metal. That when you take the phosphates out, you have to use some other kind of oxygen reducer or you'll get massive suds and oxidation. Wow, this is all so environmentally friendly. Not.

Cascade is recommending a hot soak of 2 - 3 Tbs cream of tarter to 1 quart of water for 15 minutes. I already tossed my garlic press, but I'll try it on my new toaster oven pan.

In case anyone else is interested, my chem-e friend is using Electrosol tabs. The box says phosphate free, and she's not having any problems with this detergent.