M.P.
I personally wouldn't.
So. I boiled the water all the way out of my tea kettle accidentally. Then it had the rusty stuff at the bottom. I soaked it with baking soda and scrubbed it and it seems perfectly clean. I don't know exactly what kind of metal it is, but it's a decent quality kettle, not a cheap one. Could it be unsafe to use? Do I need to trash it?
Thanks ladies, To clarify, it didn't have build up before, just red rust after I let the water boil out and smelled burning metal....:(
I personally wouldn't.
It's fine. Tea kettles (and humidifiers) will suffer from a mineral build up after awhile. It's from your water and you drink and wash in it every day. You can either use distilled water (which will have almost no minerals in it so they won't build up) or you can clean your tea pot periodically.
Try boiling some vinegar in your pot, then wash it out several times.. It should dissolve the mineral build up just fine.
Depending on how hard your water is, the minerals can vary a lot in appearance. Every so often I've dropped a tea kettle and it's like little pieces of stone will break off the inside bottom. Depending where I've lived, the little pieces can look black (like slate), tan, sort of rusty colored (if you have a high iron content) or kind of whitish.
I almost think tea kettle mineral build up should be some kind of school science project!
I would think it's fine if it looks ok.
If you mean rusty stuff as in rust, I would get a new one. If you're talking mineral build up then I think it would still be safe to use.