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topic 41066

Aluminum shiny finish destroyed in dishwasher


Dishwashers can turn aluminum gray & spongey.

Ketchup, lemon, & vinegar were partially successful, or follow the links to : metal polish, ammonium citrate, Glass Cooktop Cleaner, Barkeeper's Friend, Silvo, and Brillo, or switching to Mrs. Meyer dishwasher detergent.

Arthur Court measuring spoons 2 Arthur Court measuring spoons 4

Feel free to add your method, but scrubbing or simmering with Cream of Tartar seems most effective. For questions about the safety of aluminum, see threads 8962 & 22551.

Current question and answers:

December 27, 2020

Q. I pulled out a pie dish I use infrequently and saw that there appeared to be some minor rust spots on it. I washed it with a scour pad and dish soap without results so I decided to give CLR a try. This was a mistake and I appear to have stripped the shiny finish off the dish. I've tried googling to see if this would affect the safety on the dish but haven't found any results. I don't expect to be able to restore it because this isn't the black dishwasher stains described in this thread but rather the CLR that has stripped the metal itself. Thoughts?

Vanessa Peter
- Toronto Ontario

December 2020

A. Hi Vanessa. If someone's cake didn't turn out, so you asked them how much flour they added, and their answer was they used two cups of "that sweet white powder", you'd interrupt to confirm that it was flour, not confectionary sugar or roach powder :-)

So when you mention rust we need to confirm that you're talking about aluminum because it can't rust -- it never gets that orange-brown stuff. Please test with a magnet because aluminum is non-magnetic. I suspect you have a tin-plated steel pan, but let's confirm aluminum vs. steel part before we get carried away with a dozen "ifs-ands-&-buts" :-)

Luck & Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

Here is the full Q&A dialog, including interesting side trips, starting in:


Q. I recently placed a new shiny aluminum meat-mallet (tenderizer) in our dishwasher. It came out almost black and looks terrible. Can I do anything to restore the original finish or at least a clean looking finish. What would have caused this? Was it anodized or something? Could anodizing be removed simply by washing in a dishwasher. Was there a chemical reaction or dissimilar metal issue?

Any advice appreciated as my wife wants to kill me for damaging it. She may even use the meat tenderizer to do it! I would at least like to be killed with a clean, shiny object.

Gary Cay
Plastics - Sydney, Australia


A. Metal polish; most likely you managed to oxidize the surface of the metal. Just use whatever metal polish you have handy to remove the surface oxidization, if you don't have any, try toothpaste.

Marc Banks
Blacksmith - Shawboro, North Carolina

January 22, 2018

Q. Bought a set of Mid Century aluminum canisters. One was dark and spotty so I got some metal polish and worked on it. It is still much darker than the rest. Is that fixable? or do I need to just ... well, got find another one that matches :)

Victoria Henderson
- Ozark, Missouri


thumbs up signTake the easy way out. Sneak out and buy an identical one. Rub it a tiny bit with toothpaste, give it to the lovely lady and tell her that you "polished it" No lie, but not the whole truth either.

P.S., keep this one in the hand wash category.

James Watts
- Navarre, Florida

Cream of Tartar

affil. link
Cream of Tartar

February 15, 2011

A. Try making a paste of water and cream of tartar (available in the spice aisle at the grocery store, if not already in your kitchen cabinet). Use either a clean cotton cloth, or in this case, an old tooth brush, nail brush or sponge, and work the paste until the shine has been restored.

Kim Pace
- Fort Worth, Texas

Skip to next posting on Cream of Tartar skiptrack

Dishwasher caused white spots on aluminum cake pans

May 16, 2010

Q. I ran my 9 inch round aluminum cake pans through the dishwasher and they have a few white powdery spots on them. My questions are:
1) what are these white spots and what causes them?
2) does this mean that my pans should be tossed out? (they are pretty old - they belonged to my grandmother who was born in 1908.)
3) should I avoid putting these and other aluminum baking pans in the dishwasher?
Thank you

Marjorie Moats
bake for fun when I can - Cleveland, Ohio, USA

simultaneous May 19, 2010

A. Dishwashing detergent is quite hard on aluminum pans that have not been anodized. They have an oxide layer that allows the pan not to corrode. Clean with a plastic sponge scrubber in warm water, coat the pan with a Light coat of oil and bake at 350 °F for an hour or so. Let it cool down in the oven. Should work fine.

James Watts
- Navarre, Florida

skipback Back to previous posting on Cream of Tartar

May 19, 2010

A. Marjorie,
Aluminum is sensitive to harsh detergents. Most dishwasher detergents are alkaline in nature. The good news is, the white spots can be removed. Buy a small jar of potassium hydrogen tartrate (cream of tartar) [affil. link to info/product on Amazon] in the spice section of the supermarket. Mix in a small amount of warm water to form a paste. With a medium coarse rag rub the paste over the whole pan in a circular motion giving added time to the white spots. Rinse well with warm water and towel dry. You may have to repeat the process. I would use a mild dish detergent and wash pans by hand from now on.

Mark Baker
fellow plater - Syracuse, New York

Skip to next posting on Cream of Tartar skiptrack

May 19, 2010

A. Hi Marjorie,

This sounds like the aluminum was oxidized during the wash phase. Are you even supposed to put aluminum in a dishwasher?

Okay, so here's what's happening:

Your dish-washing detergent contains alkaline phosphates. At high pH, the 'passive' aluminum surface dissolves as Na2Al(OH)4 (sodium aluminate). This reveals 'active' metal underneath, which reacts with the phosphates in the water to form aluminum phosphate. Sodium aluminate reacts with sodium phosphate to form sodium aluminum phosphate. Sodium aluminum phosphates precipitate out of the water, and deposit onto the sites along the surface of the aluminum cookware, leaving these powdery spots.

Sodium aluminum phosphate isn't dangerous if you accidentally consume. It's often used as a leavening agent for baking. If you scrub the surface with a Brillo [affil. link to info/product on Amazon] pad, this should be fine to use again.

In the future, try to clean baking sheets by hand; dishwashers provide a corrosive environment for aluminum.

Robert Kinner
- Toledo, Ohio

May 20, 2010

A. The aluminium that the cake tins are made from is probably being attacked by the dishwasher powder. This is starting to cause corrosion which is the white spots. My advice would be to clean the tins with some of the more abrasive pan scourers to remove the corrosion, rinse well. Put a light coating of vegetable oil on the pans with kitchen roll before putting them back into your cupboard. From now on only hand wash them.

Ciaron Murphy
- South Wales UK

Aluminum meat grinder parts washed in dishwasher turned gray

November 4, 2010

Q. A friend borrowed our meat grinder and washed the aluminum parts that are not dishwasher safe in the dishwasher! The once pretty shiny silver looking parts are now dark gray and leave a black tarnish on your fingers. How can I clean it, to get it to the point where it will be safe to use again?

Tawny Dunlevy
Homemaker - Sitka, Alaska, USA

November 4, 2010

A. Hi, Tawny

I think it's safe to use, and I believe if you look it up in authoritative places you will find the same opinion expressed by the Alzheimer's Association, EPA, etc. But that black smut is unappealing and if you can get rid of it temporarily, do it.

I used your inquiry as a teachable moment for myself, taking an old aluminum ice cream scooper that has been in the dishwasher a hundred times and seeing what I could do with it. Rubbing it with a cloth soaked in vinegar took off loads of the black smut, but was generating it almost as fast as it took it off :-)
After I rinsed it, not much further black smut came off, and it was darker in color because I had dissolved any white corrosion products. I then tried a sulfamic acid metal polish and the experiment went pretty much the same. Not having any Mother's Mag & Aluminum Polish [affil. link to info/product on Amazon] at hand, I tried rubbing compound (by hand), and the result was slightly better.

Moving on to conjecture, I think you could brighten it up and remove the black smut if you buff it with a power tool (a buffer, a Dremel [affil. link to info/product on Amazon], or at least a buffing pad on a battery operated drill) and the Mother's. But I think once the anodized coating is gone, it's gone, and it won't stay shiny for long. Sorry.


Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com - Pine Beach, New Jersey
Striving to live Aloha

affil. link
"Surface Treatment & Finishing of Aluminium and Its Alloys"
by Wernick, Pinner & Sheasby
from Abe Books
info on Amazon

November 9, 2010

A. It has been a while since I've read through it, and I don't have my copy handy, but I recall Wernick Pinner and Sheasby =>
stating that you could get really good corrosion resistance by submerging aluminum in boiling water for 24 hours but that it wasn't economical for most manufacturing purposes. In this case however, if you CAN brighten it back up (even temporarily), if you have a way to boil it for long enough it MIGHT stay that way. Mind you, I've never personally tried it.

Good Luck!

Jim Gorsich
Accurate Anodizing Inc.
supporting advertiser
Compton, California, USA
accurate anodizing banner

November 2013

thumbs up signGreat idea, Jim, thanks.

Readers: Sorry I couldn't quickly find exactly what Jim was talking about (no surprise though, the book is almost 1300 pages and there have been at least six editions). But I did see graphs showing that the oxide film does continue to grow for 16 to 24 hours in boiling water before it tops out. Some other pages seem to indicate that deionized/distilled water is very important, so try boiling in a very clean enameled pot (or a pot lined with a pot liner or at least a plastic bag), and maybe change out the deionized/distilled water a couple of times.


Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com - Pine Beach, New Jersey
Striving to live Aloha

December 8, 2010 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. I washed my aluminum pressure cooker in the dishwasher. The manual says not dishwasher safe on it; however, I did not see that until later. Instead of being shiny silver it is now dull and has a pink/purple/green tinge to it. Is this safe to use again or should I discard it?

Cat Welz
- Vernon, Connecticut, USA

December 9, 2010

A. Hi, Cat.

I'd guess that the pink/purple/green tinge is a diffraction pattern caused by the very thin last of the anodized coating (sometimes you see automobile headlights shifting color as they approach you if they have anodized reflectors). With a ruined pot, this sounds like the perfect time to try Jim's proposed cure of boiling distilled water in it for 24 hours. Please let us know what happens!


Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com - Pine Beach, New Jersey
Striving to live Aloha

January 26, 2013

A. There IS hope for dishwasher discolored aluminum items. My beautiful Arthur Court Measuring spoons were accidentally washed in the dishwasher. I researched on-line and decided the "least likely to do more damage" approach would be the Brillo [affil. link to info/product on Amazon] Pad solution. IT WORKED! I rubbed & scrubbed with a blue filled pad until they were covered in blue goo. This is going to take serious rubbing! Then I used a soft bristle brush & warm soapy water to briskly brush them repeatedly to remove all tarnish and blue goo. I used a little more dish detergent & clean warm water to brush them again and rinsed in warm water. Then I dried them with a soft clean towel. Never underestimate a Brillo Pad & elbow grease! Amazing! I am submitting photos.

Arthur Court measuring spoons 1 Arthur Court measuring spoons 2 Arthur Court measuring spoons 3
Arthur Court measuring spoons 4 Arthur Court measuring spoons 4

Amber Miller
- Iowa City, Iowa

November 26, 2017

A. Have similar SMEG cooker with similar burners which also turned black in the dishwasher. A Brillo [affil. link to info/product on Amazon] pad removed this and restored back to a shiny finish in minutes.

Jon Pearce
- London, England

November 24, 2013 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. Hello. I have 2 vintage aluminum (I believe cast) decorative bowls, on of which is a Royal Hickman RH7 Signed Bruce Fox Aluminum Leaf Tray. After a party, my husband put them in the dishwasher and they now have lost their luster and there are darker streaks and spots. Is there a way to restore them?

Karen Caldwell
- Sonora, California

Glass Cooktop Cleaner

February 26, 2015

A. I sought this site because of discolored aluminum.

After reading some of the answers I picked up the sponge that I had just used with a preparation to clean my glass stove top. I spread it on the 50 year old "Wearever" Aluminum chicken fryer that had belonged to my mother. To my surprise, when I came back 10-15 minutes later, a lot of the discoloration was removed, I applied more and let it sit with a good result. Now I am treating the bottom of the pan.

The brand is WEIMAN and it is identified as Glass Cook Top Cleaner [affil. link to info/product on Amazon].

I haven't tried my cake pan yet.

Karen Kettleson
- Crosslake, Minnesota USA

January 31, 2016

thumbs up signDiscolored aluminum cake pan
This is an endorsement to Karen Kettleson's post dated 2/26/15. Weiman Glass Cook Top Cleaner [affil. link to info/product on Amazon] applied with a scouring pad and wiped off with paper towels did the trick for me. It took three passes but the pan was very heavily stained and is nearly spotless now. Note: please wash off the cleaner thoroughly before using your cookware. Thanks for posting, Karen.

Lydia Wiswell
Curexo Tech/ThinkSurgical - Cupertino, California, USA

Cooktop Cleaner Paste

February 24, 2016

thumbs up signAffirming the use of cooktop cleaner. The brand I used was Cerama Bryte Cooktop Cleaner [affil. link to info/product on Amazon] and it almost completely restored the aluminum lid to my coffee urn. Yay!

Heather Alexander
- Wenatchee, Washington USA

November 20, 2016

A. Used Cerama Bryte Cooktop Cleaner [affil. link to info/product on Amazon] and yellow scrubber that came with it and it removed all the white residue and most of the black from my cookie sheet. Thanks for the glasstop cleaner tip.

Michele acker
- Columbus Ohio usa

January 13, 2019

A. Based on other suggestions here, I used grade 0000 steel wool [affil. link to info/product at Rockler] and glass stovetop (paste) cleaner, and it completely restored knives and other pieces that had been "ruined" for years.

Allyson Saaf
- San Antonio, Texas, USA

Barkeeper's Friend

March 16, 2015

A. I was bummed to find my retro cake cover discolored from putting it in the dishwasher. Found the recommendations here and modified (can't help it, I'm a guy) some of the suggestions and results were spectacular.

I took damp paper towels folded X3, wrapped them around the cake cover; drizzled white vinegar atop the cover to seep into paper towels then put it in plastic shopping bags to soak. Removed them and made a paste out of Barkeepers Friend [affil. link to info/product on Amazon] and water and scrubbed some with a scrub sponge.

Cleaner than it's ever been. Still some slight telltale signs of discoloration but I'm a happy guy; my cake won't go stale.

doug deane
- hyannis, Massachusetts

July 20, 2016

A. Try Barkeepers Friend [affil. link to info/product on Amazon] I made a paste and rub most of the grey off easily. soaked in water with some of the bar keepers friend for about 10 minutes, grabbed a scotch brite pad and with very little effort in less than 2 minutes it was like new.

Chad Wilkinson
- Sherburn, Minnesota

November 7, 2017

A. I read many of the responses, then combined all the knowledge gathered, along with what I had on hand, and discarding anything remotely dangerous, I came up with an amazing result. I tried it again & again with the same results.


My dishwashing disaster was a very old aluminum sieve that I loved. Here's what I did: I applied Barkeepers Friend [affil. link to info/product on Amazon], smeared it around with a folded wet paper towel, and let it sit for 5-10 minutes. Then I used the same wet paper towel to rub briskly back and forth over the area. I rinsed it well and the area was cleansed of the blackish mess! But it wasn't bright, as noted by others that had used that technique. But here's what I did differently: I topped it off with a very light rub of Brillo [affil. link to info/product on Amazon]. Now it was shiny! And it didn't take hard and lengthy scrubbing/rubbing, and no scratches. (The scratches in my photos go back many years)

Renate Shanahan
- Edison, New Jersey, USA

February 8, 2016

Q. Hey everyone,

I was a goof this last weekend and washed my girlfriend's Starbucks stainless steel cups in the dishwasher. I just saw a sink full of dishes and a pile of clothes by the bed and did them all before I picked her up from work for dinner, but I might have ruined her favorite cups. She says the water she drinks from them tastes funny now. Is there any way to save the cups that she absolutely loves?

Thanks everyone!

Ken Newton
- Lake Stevens

A. Hi Ken. You're sure they're stainless steel rather than aluminum? I'm very surprised that a dishwasher would have such an effect on stainless steel cups. Stainless flatware goes into hundreds of millions of dishwashers every day. But if they are aluminum, this page has ideas for you :-)


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

August 13, 2016

Q. We rented our house and someone put aluminum Pans in the dishwasher. I cannot get the black out of my dishwasher. HELP. Martha

Martha Dixon
- Bluffton South Carolina

? Hi Martha. I've heard of dishwasher damaging aluminum but I've never heard of aluminum damaging a dishwasher. Can you point us to any reference that leads you to believe this is the cause of the blackening? Are the surfaces in question plastic, or stainless, or what?


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

skipback Back to previous posting on Cream of Tartar

January 10, 2017

A. I tried using the cream of tartar and water paste since I had it on hand. It worked out pretty well I spent less than 10 minutes and may have achieved better results if I put more effort into it. I used it on my aluminum garlic press that went through the dishwasher: wiped for about 30 seconds with the paste then rinsed under cool water.

Amber Clark
- PORTERVILLE, California, USA

Skip to next posting on Cream of Tartar skiptrack

May 5, 2017

Q. I got a new dishwasher with a stainless steel interior. It does all pots and pans, but two cake pans, turned dark gray and mottled. Could it be a chemical reaction between the stainless and the aluminum? They weren't affected in porcelain lined dishwasher. Any suggestions?

Kathy Britten
- Karlstad, Minnesota USA

May 2017

A. Hi Kathy. The kind of reaction you are envisioning is electrochemical, and can only happen if there is contact (electrical continuity) between the aluminum and the stainless.

Whether the problem was some other stainless item touching the pan, a change to a more alkaline dishwasher detergent, or just gradual wear of some clear coating on the cake pans, the thing remains: aluminum doesn't belong in a dishwasher which uses the conventional extremely alkaline dishwasher detergents; they destroy aluminum regardless of other factors.


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

skipback Back to previous posting on Cream of Tartar

June 5, 2017

A. I just tried all the above suggestions on a formerly shiny, now tarnished, aluminum bowl. Forget the glass top cleaner, the lemon & salt, the lemon, the vinegar & baking soda.

After wasting 1 hr scrubbing, forget everything except: in a large pan add water & cream of tarter (I did about 2 T); heat to just below boiling; let pan/bowl/item sit until color changes to normal -- about 30 minutes. If you have a large bowl you will need to rotate it as the color changes. It's a lot easier than scrubbing for a long time.

Jo Polst
- Price, Utah USA

June 18, 2017


A video on the laziest method to clean aluminum after dishwasher, no scrubbing needed -- Oven, roasting pan, and potassium hydrogen tartrate (cream of tartar) [affil. link to info/product on Amazon].


Andrew Terrence
- Chicago, Illinois

August 24, 2017

thumbs up sign  Thank you for this site! I had no idea my mother's 1950's garlic press was supposed to look this good!


Now to tackle the antique 21.5 All American pressure canner I was just given.

Catherine Bradford
- Saint Louis, Missouri USA

November 20, 2017

A. Hi I have a SMEG oven and decided to put the burners in the dishwasher. After 10 mins they looked like they were ruined. I searched to find a way to rectify this - I tried vinegar, coke, polish etc. Nothing worked until I found Silvo [affil. link to info/product on Amazon] tarnish guard. I polished for ages and voila they are shining again. I am in England if that makes any odds

discolored gas stove burners from dishwasher 15155-3c   15155-3a   15155-3e   15155-3d   15155-3b  
gas stove burners cleaned with Silvo 15155-3f

Jackie Cayless
- south ockendon essex

Ammonium Citrate

January 24, 2018

A. Try ammonium citrate 5% pH 7 solution (dissolve 50 gms citric acid in 1 lit water and add some ammonia until pH is 7). Hope it helps and good luck!

Goran Budija
- Zagreb, Croatia

July 16, 2018

Q. My jumbo Bialetti espresso pot (cast aluminum went from shiny and smooth to charcoal-black after a wash with Cascade Platinum.
I tried scotch-brute scrub, brillo scrub, cream of tartar in boiling water soak for 6 hours. Pot is brighter but remains dull and black smudges appear if I use a paper towel to wipe it. I'l try buffing next, but I can't easily buff the interior. Has anyone tried the ammonium citrate method suggested above (from Zagreb, Croatia) ??

fred buehrer
retired - Manchester, New Hampshire

March 27, 2018

A. My experience with Cascade Platinum [affil. link to info/product on Amazon] is that it takes off the metal from utensils and pots & pans, and makes spoons black. I have no idea what causes this, but as far as a dishwasher detergent, it's the best out there and works exactly how they describe it. So keep the metal out and you will be okay.

J. Miller
- Las Vegas, Nevada, USA

April 18, 2018

Q. The aluminum corrosion problem with our new Bosch dishwasher is that anything aluminum is just plain eaten up: measuring spoons, garlic press, and, aluminum bottoms of otherwise stainless steel Farberware pots and pans. Nothing like this has happened in the 40 years of washing the Farberware in dishwashers. On the pot bottoms, it can start off with a coppery/bronze tint but progresses to pitting. This is our first stainless-steel-interior dishwasher, and it no doubt runs at the highest temperature in our experience. No change in detergent (Cascade Platinum, 15X Power). I get that there's chemistry going on, but why now? And what can be done to stop it from happening? The wife will not wash the pots by hand (I do most of the cooking).

Richard Kerr
- Bethesda, Maryland, USA

April 2018

A. Hi Richard. I have a Bosch dishwasher with stainless interior as well, but we don't put aluminum in the dishwasher; it's just a bad idea. Personally I don't think the stainless interior is the problem, but you may be on the right track with the water temperature. Maybe you can turn down the water heater as long as the clothes washer keeps working.


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

May 1, 2018

A. With more research and a bit of experimentation, the appearance of aluminum corrosion with a new dishwasher can likely be attributed to a combination of:
previous removal of phosphates (which had some protective effect)from dishwasher detergents;
the addition of more corrosive agents to detergents to make up for the missing phosphates;
the higher water temperature of the new dishwasher;
the higher concentration of detergent in a more water-efficient dishwasher;
and the longer contact time of the new dishwasher.

Switching from Cascade Platinum (15X) to plain old Cascade (10X) helps a good deal but does not eliminate corrosion. Aluminum-clad pots will have to endure it; the rest of the aluminum will be replaced with stainless steel.

Richard Kerr [returning]
- Bethesda, Maryland, USA

Skip to next posting on Farberware skiptrack

December 30, 2018

Q. So I just washed my new meat grinder in the dishwasher, and got the same effect... boil it in water for a day to get rid of the grime? Or just buy new from the manufacturer? Totally not worried about it being shiny. Just want to make some sausage.

Matt Kohser
- Pittsburgh, Pennsylvania United States

December 2018

A. Hi Matt. Sorry about that. The manufacturer should probably have warned you. I personally like the cream of tartar answer the best.


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

August 29, 2019

Q. Hi I just put my meat grinder parts in the dishwasher and all came out grey. Black just kept coming off, I read on pinterest about ketchup cleaning aluminum, it worked great [they say], just coat the pieces , let sit for 5 min. wipe with lots of paper towels, repeat if you need to, then rinse with water. I haven't used it yet. Can I still use the parts even thought they aren't shiny?

Dorothy Turner
retired - RR#1 Dashwood canada

August 2019

A. Hi Dorothy. I am not familiar with the use of ketchup on aluminum (cream of tartar seems the most highly suggested fix on this site). But if the ketchup solves the problem, great. There is no need for aluminum to be shiny for it to be safe and usable. Good luck with it.


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

Protecting Aluminum by boiling?

February 5, 2020

Q. Good morning, been searching around for answers and most have linked me back to this page. Nice work by all.

My situation/ Question:

Purchased a used dirty/moldy electric food slicer. Cleaned most by hand. In a weak moment, I put the food carrier portion in the dishwasher, thinking it was stainless. Needless to say it was aluminum and it came out oxidized and ugly. Tried lemon juice, vinegar, barkeeper's friend all with varying results. Ended up hitting it with a 320 grit 3M scotch pad and it evened up the finish and gave a slight shine.
Now on to protecting it. It's the actual food carrier so chemicals are out. I read a few posts referring to "Wernick Pinner and Sheasby" -- don't mind buying or checking out a book, but I'm afraid this one would make my head hurt. The process referred to was to boil the Aluminum parts for 24 hours in distilled water & doing that "will put a thin but highly protective coating on the aluminum". But the posts were not followed up with results. Someone also mentioned "If you plan on using these mugs for drinking, thin coat of sulfuric anodizing should suffice. Just seal in DI water" but not sure of that process.
I have a 15-gallon stainless brew kettle with a stainless heating element that would be big and powerful enough to do the boil. Which leads me to two questions:
Has anyone done this successfully?
Will the Distilled water harm the stainless kettle during the process?
Do you have any other recommendations for my situation that would be "food safe"

Hobbyist - Woodbridge, New Jersey USA

February 2020

A. Hi James.
Hundreds of millions (if not billions) of people have boiled water in aluminum, so it's certainly 'food safe' as far as most people view it (some, of course, feel that cooking in aluminum pots is dangerous).

Although it is not impossible to do sulfuric acid anodizing at home, this is a multi-step process involving acquisition of equipment, chemicals, and knowledge that you are not going to learn, practice, and do for the sake of one pot.

As for "has anyone done this successfully", I don't think anyone would be able to quantify their success anyway, but this is the back story: Aluminum is a very active metal that oxidizes instantly, automatically leaving a very thin oxide coating on the surface. Sulfuric acid anodizing is an approach that employs electricity and acid to engineer that oxide coating to maximum thickness, utility and corrosion resistance. Boiling in D.I. water for up to 24 hours is a compromise between doing nothing and sulfuric acid anodizing. I think authoritative sources like Wernick Pinner and Sheasby indicate that it can be of some value and that the thickness will continue to build for up to 24 hours. It's perhaps possible that scholar.google.com or surfacequery.com might locate a controlled study if you're more patient than me :-)


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

February 12, 2020

A. There are many chemical oxidation processes for aluminum; try USPTO gov website (expired patents). Sodium aluminate, potassium ferricyanide, ferric citrate, or potassium permanganate and calcium hydroxide based are just some of them ... Hope it helps and good luck

Goran Budija
- Zagreb,Croatia

Wire brush inside of aluminum pot

February 13, 2020 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. I have used a circular wire brush in a drill to clean my 40 year old aluminum pot. Is there any problem with this? Was pot likely coated? Is brushed surface going to allow metal particles to now be combined with cooked foods?

David Preddy
- Henrico, Virginia

February 2020

A. Hi David. The Q&A immediately above yours seems applicable. This site has, without exaggeration, hundreds of opinions and references covering both sides of the question of whether aluminum is safe. Please search the site with the term "safety of aluminum" if you have time to spend on the question. If not, all I can say is some people (including me) think it's safe, based largely on the fact that hundreds of millions of families have cooked with it for generation after generation and no 'smoking gun'; some think it's not safe :-)


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading

skipback Back to previous posting on Farberware

October 3, 2020

affil. link

Back to the Farberware and Bosch dishwasher discussion ... I also have 40 year old aluminum-clad Farberware that I've been washing in the DW all along. Suddenly the aluminum bottoms started turning white and chalky. I cleaned them with SOS successfully. What has worked for me is changing detergents. Mrs. Meyer's pacs are the only detergent I have found that don't make the aluminum white. Must have a different chemical formula. We do have a lot of lime in the water here, but have a softener, and that has not changed.

Kathy Miner
- Madison Wisconsin

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