We have white ceramic cereal bowls. They are now gray with streaks from the stainless steel spoons. I can reduce the gray so some extent with much intense scrubbing, but I’m wondering if there’s a cool, easy way to clean these bowls with the right material. I’ve used Comet cleanser and that seems to do it a little better. But I’m thinking there’s probably a chemical reaction I can take advantage of. Or no? Dopers?
As a tile installer, I remove metal marks with:
- pencil eraser
- abrasive cleaner/sponge
- CLR cleaner
you could use hazardous chemicals to remove metal though there would be problems later for cleanup. it would takes lots of days of high liquid volume to clean and then decontaminate the bowls. something that would be done in a chemical lab but not for home.
ceramic is very porous and what you use to clean it will get into crevices and need to be removed for it to be food safe.
mild safer methods methods are best for food bowls.
use wooden or plastic or ceramic spoons.
One assumes they are glazed bowls - so porosity will be much less an issue.
Anyway, the obvious answer would by acid - in particular hydrochloric acid is easily available and used for removing metal markings on other surfaces. As to its toxicity - well it is and it isn’t. It is corrosive. It is dangerous when concentrated - so much so that I would actually be inclined to suggest you not try. But a simple washing of the bowl would remove pretty well all of it, and any residual is not toxic. Indeed, your stomach naturally contains hydrochloric acid in sufficiently high concentration to be usefully antiseptic and corrosive.
But handling acid of the concentration needed to get the marks off is not something done lightly. Gloves, eye protection, lots of care, are minimal. Hydrochloric acid is commonly sold in either pool shops for maintaining the pH of pools, or in hardware stores for both pool owners and for cleaning concrete and brickwork.
You want Barkeeper’s Friend. It’s sold in a gold can with the other cleaners (Ajax, Comet, etc.) at many grocery stores. It is AWESOME at getting rid of metal marks from ceramic. I used to live in a place with a white-ceramic kitchen sink, and metal marks were inevitable. This got them right out with some light scrubbing. I can’t recommend the stuff enough.
Please try it before going the acid/eye protection route.
Quoth Francis Vaughan:
That’s way overboard. Wear latex gloves while you do it, and if you get any on yourself, rinse it off. There are plenty of things that folks take for granted that are a lot more dangerous than hydrochloric acid. Heck, plain ordinary boiling water is probably more dangerous.
Hey, cool! I used some **Bartender’s Friend **and it worked very well! I think a second go-round with the bowls will do the job. And clearly there’s acid in the mixture. I know this because the smell I detected was very similar to one that I used to get when I prepared steel wool for an experiment we used to do in class. The steel wool had to be free of any coating so that it could interact with the air (and rust) so I’d soak it in vinegar. And sure enough, it would smell, and the reaction I was smelling was a metal-acid reaction similar to the one in the bowl I’m trying to clean (with oxalic acid, as it turns out.) Thanks, Dopers.