[Enthalpy]

Hi everybody!

I used sunflower oil at normal frying temperature in my new pan, left the residues for a day in the air at room temperature, and now soap and its variants on a sponge don't remove the brown dirt.

Cream cleaner and a hard brush work well at the stove, but I don't want to scratch my still smooth pan. The outer face is aluminium and I don't care about scratches there, but the inner face is so-called "ceramic", still anti-adhesive, which I'd like to preserve.

I tried ethanol+isopropanol+water, nothing efficient. Dish soap and hand soap don't work. I'd have hydrochloric thing and sodium hydroxide and bicarbonate. I can find the usual household compounds, maybe petroleum or turpentine.

Ideas please? Thanks!

[jeffmoonchop]

Put dry baking soda on it, and with a wet cloth rub the area. The powder may not be too abrasive.

[Enthalpy]

At the outer face, not covered with "ceramic":
I tried first with talcum, no effect.
Baking soda, no effect. At least, it didn't corrode aluminium in cold water.
Even cream cleaner didn't remove the hardened oil within the accessible mechanical effort.
Sunflower oil baked and left several days in the air gets really hard, I know it now.

At the inner face:
I started directly with cream cleaner and a brush, this removed the hardened oil, but now I've lost the antiadhesive behaviour.
Maybe I'll try to polish the inner face. I have 7000 grit sandpaper.

[wildfyr]

vegetable oils contain double bonds which can polymerize in the presence of oxygen and UV to form quite hard surfaces indeed. They are not soluble, being crosslinked matrices, so all you can do is try to swell them with an organic and removed mechanically. Perhaps mineral oil could soften it enough that you can remove more easily?

[Enthalpy]

The situation worsened as I forgot the pan with sunflower oil for half an hour at moderate heat. Brown inside, a bit dark.

A night with water and dish soap didn't soften the layer. Brushing with dish soap failed hopelessly.

The C-O cross-links being too stable, I thought I had to saponify the esters, and used sodium hydroxide powder in little water, with a brush. Whether this was the effect or not, it took some effort, the dish gloves withstood the base, and the inside of my pan (with "ceramic" coating) is clean.