It was easy. I finally got some vinegar and filled it up and let the kettle sit overnight. Rinsed it and gave it a wipe with a wad of paper towel and the scale and residue from the scale is all gone.
Shoulda done it earlier. The wasted psychic energy, every time I peered in and saw the scale…
I keep a box of citric acid crystals around for this and the coffee pot/espresso machine. It descales as well as vinegar (for the kettle I just put a few scoops in and boil with water) and there’s no aftertaste/smell like there is with vinegar.
Our water is so hard here I periodically take the kettle into the shop when it doesn’t boil water very quick, and use the needle scaler on it to knock big slabs of scale out of it.
Have you tried selling those as slabs of marble to some local sculpture artists?
I mix half water half vinegar and boil it. Then I don’t need to wait overnight. Also boil a few full kettles of clean water to remove the vinegar taste.
