I use an old Wear Ever heavy aluminum coffee pot for boiling water. I don't allow unused water to sit in it. It has stains inside and needs a good cleaning. It has white residue at the water line that I cannot remove. For now I have been washing it out with soapy water but not using anything abrasive. Any ideas on how to clean it? I just want to be sure it is safe to use, if the stains cannot be removed so then they are meant to be.

  • IIRC corroded aluminum is white.
    – nick012000
    Commented May 26, 2021 at 5:24
  • Can you recognize whether this is scale?
    – rumtscho
    Commented May 26, 2021 at 6:40
  • This site should be renamed "metals and alloys" or "microbiology" ;)
    – Alchimista
    Commented May 27, 2021 at 8:17
  • Up Next: How to clean your silverware with just some aluminium foil & baking soda ;)
    – Tetsujin
    Commented May 27, 2021 at 9:47

1 Answer 1


You can buy kitchen-safe aluminium cleaner & descaler - the white could easily be limescale.

If you look at 'home-style' cleaning guides, then everybody seems to have a different opinion - some choose baking soda, some choose vinegar.
Now, I'm no chemist, but I fail to see how both of those would work, one acid, the other alkaline. I also don't know which would clean the aluminium or which may damage it. I did once manage to completely ruin 2 stove-top espresso makers by getting this wrong.

On the other hand, you can get a litre of commercial cleaner/descaler for a couple of quid/bucks/euros, so why not let the experts take over?
They're going to have figured out what removes scale & tarnish, yet doesn't harm the aluminium. A look at a data sheet says it's Orthophosphoric acid.
I checked data sheets for 'regular' cleaner/descaler & aluminium-specific cleaner/descaler. Both contain the same acid, though other ingredients may differ.

Google found this one in the UK, but I'm sure you can find something similar close to where you live.

  • 2
    I'm no chemist either but know enough that to react off limescale you need acid: vinegar or lemon juice are the easiest edible acids (also phosphoric acid in cola), but it will need a very good rinse afterwards anyway. On aluminium I'd go dilute and patient rather than rushing; heat helps. The use of baking soda in cleaning (apart from grease, which reacts with alkaline compounds) is either to produce CO2 bubbles by reacting with acid; the bubbles give good mixing and agitation of the reaction, or to acts as an abrasive in a slurry. Neither is much use here
    – Chris H
    Commented May 26, 2021 at 9:34

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