How to Clean/Fix Burnt Stovetop after Kitchen Fire?

Question

What is the best way to clean or repair this stovetop?

Background:

As we were boiling some water, there may have been some residue grease on either the stovetop or the wall next to the stovetop, and the wall/stovetop caught on fire, which lasted for approximately ~ 1 minute.

After putting out the fire with a fire extinguisher, and after cleanup, there is a rough/coarse ring around where the pot was sitting.

If we try to scrub it with a paper towel, it will rip the paper towel, and if we try to scrub it with a towel, it will wear down the towel as well (it feels like sandpaper).

Does it seem like this can be cleaned or repaired, and if so, what is the best way to get it fixed/cleaned?

Answer 1

Congratulations on putting out the fire. It's time for a new extinguisher, even if the one you used still has pressure, since the pressure will now leak out in time.

The residue looks like burned dry chemical from the extinguisher.

Most of the contents of a typical BC dry chemical extinguisher is sodium bicarbonate, aka baking soda. When overheated, it releases CO2 and becomes sodium carbonate, aka washing soda. Washing soda is soluble in water.

If the extinguisher was ABC dry chemical, it contained ammonium phosphate, which is also soluble in water. (Thanks to @ThreePhaseEel for the correction.)

Use a sponge or paper towel or rag to thoroughly wet the crusty material, then soak up the excess water and do it again. It may be useful to use a bucket or other container to hold water to wet the rag, rinse it, and wet it some more.

These chemicals are somewhat caustic in solution with water, so it may make your hands feel slippery. Use rubber gloves if your skin is sensitive.

If the residue resists dissolving with ordinary water, use white vinegar if your stovetop instructions permit it.

Most of the residue should come off with repeated rinsing and wiping. If the glass remains rough, then it has unfortunately been etched by the exposure to high temperature alkali, and the etch is permanent. Replacement of the top may be the only cure in that case.