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Chalk board-like Anodized cookware exterior

I purchased Kirkland anodized cookware as a wedding gift; similar in quality to Calaphon. I am very satisfied with the set; however the pieces that we use more often have developed a chalkboard-like surface on the exterior; the interior seems fine.

My wife was washing the pieces in the dishwasher; we are not going to anymore because of this result. We learned our lesson. However, does anyone know any way to restore the finish on the exterior anodized cookware? Thanks

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  1. Try a brief scrub with Barkeeper's Friend.

    1. DO NOT USE barkeepers friend on your anodized cookware it will ruin the surface! Do not use any cleaners with bleach either. They will oxidize the anodized surface. You can use a paste of baking soda or something like Bon Ami which has no bleach. It is tough to find but you could use comet or ajax cleansers that have no bleach. The problem is you may have already ruined the anodized surface by using the dishwasher. Hard anodized calphalon and similar products can be re-oxidized overtime and that may be what the dishwasher has done. Calphalon lifetime warrantys are voided once you have put them in a dishwasher.

      2 Replies
      1. re: kayakado

        Ummm... I've used BKF on my All-Clad LTD with no ill effect. Also, anodization is a process of oxidation -- the oxidized surface prevents further damage from happening to the metal not exposed. I do beleive that bleach will do a number on the surface though -- hmm... is there a chemist in the house? hehe... because bleach works via oxidation as well, and presumably you would need a reducing agent to do damage to the anodized surface. I'll have to figure this one out.

        To the OP, I'm not aware of anyway in which you can re-anodize in your home the surface of your cookware unless you have access to the proper chemical baths and electronic equipment!

        1. re: kayakado

          Just a friendly FYI...Calphalon on their page says absolutely no baking soda for their hard anodized pots. I would think Ajax and Comet would be terrible for it as well. Calphalon specifically recommends Barkeeper's Friend for their hard anodized products.

        2. The good news is that your cookware is probably perfectly useful. The bad news is that you are stuck with cookware that is going to look a little gnarly, and might react with particularly acidic foods.

          The anodization process involves building a thick dense layer of oxidation that is crystalline (basically sapphire) which is tough and non-reactive to foods, most of which are acidic, but soluble in an alakaline environment, like your dishwasher.

          Normal aluminum oxidation (the chalky white stuff) is a chemically different substance -- it is thin, weak, and washes off. (Consider that graphite and diamonds are both pure carbon -- and otherwise entirely different!) It is easily scoured off, exposing the shiny metallic aluminum beneath. Metallic aluminum is soft and reacts with foods -- not a good thing for cookware.

          Anodization involves sulfuric acid dips and a healthy source of DC power -- way beyond a DIY project. If you know somebody in the curtainwall business, they might be able to sneak your pots onto the line. No guarantees that you will have something safe for cooking food, but it will look nice.

          If having ugly cookware drives you nuts, or if it is misbehaving (turning your mashed potatoes a lovely shade of grey, for instance), then chunk it and start over. Otherwise, relax and cook 'em into the ground.

          1. Your best bet now that you've ruined the surface is returning it to Costco, if you don't mind using their liberal return policy to your advantage.

            1. mddong- Unfortunately many manufacturers simply apply an anodized coating to regular aluminum, instead manufacturing them totally out of anodized aluminum. Otherwise they could be buffed or resurfaced without any ill effects. It is so sad manufacturers currently sell the inferior anodized coated junk.

              2 Replies
              1. re: RShea78

                Can you really make an item entirely out of aluminum oxide?

                1. re: rockfish42

                  You mean as in "grinding wheels"? (That is the only thing I can think of, that is actually made out of aluminum oxide.)

                  As far as solid anodized Al cookware, the company that made them, went out of business in the 80's. My Dad had a set but tossed them when he went and purchased a Saladmaster set of SS.

                  I believe currently no one makes them solid anymore, but Al is simply a item I can live without. Too many Don't(s) to deal with.

                  Another read is the chowhound link below.

              2. I would take them back and try again. Dishwashers will strip the anodized surface right off your pan and it sounds like it's already happening. If you read the instructions that came with the set I can guarantee it said DO NOT WASH IN THE DISHWASHER. In other words, they are half way to RUINED. There's no way to reverse the process. There's a good reason people buy stainless steel cookware. :-) You might want to consider that when re-buying your pans at Costco.

                1. I just stumbled upon this thread and was really happy as we had a petsitter a while back put one of our pots in the dishwasher and it has that same look. When I first started reading here, it sounded like it's just a cosmetic thing which bothers me not at all. But others refer to it as being "ruined." Ruined, how? Please explain. Again, I only care how it cooks not looks :)

                  8 Replies
                  1. re: c oliver

                    The anodization process can be reversed by extreme temperature or if exposed highly acidic or alkaline substances. Most dishwasher detergent is extremely alkaline. In fact calphalon will not honor your warranty if you wash your cookware in the dishwasher.

                    1. re: rockfish42

                      But is this just a looks or a cooks problem? Sorry to ask again but not understanding.

                      1. re: rockfish42

                        PS: I've been using this pot for a year since the incident and no one's died and it seems to function as before. So if "ruined" what would that do?

                        1. re: c oliver

                          The anodization makes the pan nonreactive, harder and more nonstick. Without that layer you probably won't hurt anyone, it just might taint heavily acidic food and be generally harder to clean.

                          1. re: rockfish42

                            Excellent info. Thanks for taking the time to explain a little more. For this medium sauce pan, I'm not as concerned then as I would be for my saute pan. And I now leave written instructions for people!

                      2. re: c oliver

                        ""But others refer to it as being "ruined." Ruined, how? Please explain. Again, I only care how it cooks not looks :)"

                        Sorry if this sounds gross, but if I burp and it tastes like Dawn (or any brand of dish soap), it is Frisbee and into the junk pile she goes.

                        EDIT (Yes! My reference is specific to cast iron)

                        1. re: RShea78

                          So are you saying that being less reactive, less hard and less nonstick (assuming rockfish42 is correct) means that it's more porous? More than cast-iron? When I burp (my husband says that's poisons that need to get OUT!), I haven't noticed Dawn so I guess I'm alright. Maybe just one washing didn't do it in :)

                          1. re: c oliver

                            It shouldn't retain dish soap flavors despite it being somewhat porous. Many restaurant kitchens use plain aluminum pans with no obvious off flavors. You might be able to detect some if you cooked something acidic for an extended period of time.

                      3. If the cookware has only been in the dishwasher a couple of times try this process. Scrub the dry exterior anodized surface with the green side of a Scotch-Brite scrubber for 10-15 minutes going with the grain of the pan. Then use a glass cook top cleaner made for electric stoves (i.e. Weiman Glass Cook Top Cleaner). I've tried this process several times and our pans look brand new.

                        1. thank you! this is an old thread but found it inline with what i was looking for. so did someone find a solution to restore the look of hard anodised cookware after someone accidentally dishwashes it? need help with this please.