Cleaning: Awakening & Resetting Unglazed Ceramics / Yixing

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pedant
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Sat Aug 01, 2020 9:55 pm

I'd scrub with baking soda paste and a qtip or paper towel covered finger
OhThatNinja
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Sat Aug 01, 2020 10:53 pm

debunix wrote:
Sat Aug 01, 2020 9:15 pm
The percarbonate might be a good next step.
Sounds good. I'll give it a try.
OhThatNinja
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Sun Aug 02, 2020 6:37 pm

Update:
after four boiling sessions with baking soda and citric acid (I used lemon juice) alternating them, most of the stains came off! There are faint stains here and there but if you look at my previous picture, this is day and night.
Old Yixing - after baking soda and citric acid baths.jpg
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I'm pretty happy with this result and might even call it a day. I did search for sodium percarbonate on Amazon but it seems to be out of stock at the moment.
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Victoria
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Sun Aug 02, 2020 8:29 pm

OhThatNinja wrote:
Sun Aug 02, 2020 6:37 pm
Update:
after four boiling sessions with baking soda and citric acid (I used lemon juice) alternating them, most of the stains came off! There are faint stains here and there but if you look at my previous picture, this is day and night.

I'm pretty happy with this result and might even call it a day. I did search for sodium percarbonate on Amazon but it seems to be out of stock at the moment.
Looks very good! Congrats. Hopefully the lemon juice had all organic particles filtered out, since that could lead to mold. White vinegar works well. In the USA percarbonate is expensive, so baking soda really is a good alternative for less problematic staining and encrusted build up.
OhThatNinja
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Sun Aug 02, 2020 10:23 pm

Victoria wrote:
Sun Aug 02, 2020 8:29 pm
OhThatNinja wrote:
Sun Aug 02, 2020 6:37 pm
Update:
after four boiling sessions with baking soda and citric acid (I used lemon juice) alternating them, most of the stains came off! There are faint stains here and there but if you look at my previous picture, this is day and night.

I'm pretty happy with this result and might even call it a day. I did search for sodium percarbonate on Amazon but it seems to be out of stock at the moment.
Looks very good! Congrats. Hopefully the lemon juice had all organic particles filtered out, since that could lead to mold. White vinegar works well. In the USA percarbonate is expensive, so baking soda really is a good alternative for less problematic staining and encrusted build up.
Thanks, Victoria!
This spot spent almost entire day on the stovetop today but it was definitely worth it. I followed up with white vinegar after the last baking soda bath (that was suggested in your guide actually) so technically I've tried all three (baking soda, lemon juice and vinegar). That is probably as clean as it will get without percarbonate.
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debunix
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Mon Aug 03, 2020 12:05 am

You can bake baking soda to generate washing soda, that might be a bit stronger as a cleaning agent.
gregcss
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Thu Aug 27, 2020 8:34 pm

pedant wrote:
Wed Jul 22, 2020 7:34 pm
probably insoluble carbonates.

dissolve with acetic acid (white vinegar) or citric acid solution. can use hot solution for faster results.

rinse it out with plenty of water in the sink afterwards.

just like descaling a tea kettle or coffee machine.
I've descaled glass and stainless steel kettles using distilled white vinegar and it works wonders. Now that I have a clay kettle that could use a bit of descaling I took pause before using the same vinegar. I am worried that the scent and taste will get absorbed into the clay. Someone informed me about using sodium carbonate+hydrogen peroxide (though this looks to be what sodium percarbonate is) and hot water to remove scale, then sparking water to neutralize remaining solution.
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pedant
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Thu Aug 27, 2020 10:04 pm

gregcss wrote:
Thu Aug 27, 2020 8:34 pm
pedant wrote:
Wed Jul 22, 2020 7:34 pm
probably insoluble carbonates.

dissolve with acetic acid (white vinegar) or citric acid solution.
...
I've descaled glass and stainless steel kettles using distilled white vinegar and it works wonders. Now that I have a clay kettle that could use a bit of descaling I took pause before using the same vinegar. I am worried that the scent and taste will get absorbed into the clay. Someone informed me about using sodium carbonate+hydrogen peroxide (though this looks to be what sodium percarbonate is) and hot water to remove scale, then sparking water to neutralize remaining solution.
sorry, i don't understand that advice. i can see no reason why percarbonate would help you remove limescale. sparkling water afterwards makes no sense, either. rinsing it out in the sink would remove percarbonate, so there'd be no need to 'neutralize' anything.

you need to use an acid. acids react with limescale (which is mostly calcium carbonate) to form CO2 and soluble calcium salts.

as for acetic acid (white vinegar), the smell won't linger for long if you do a good job of rinsing, but it's just smelly and therefore annoying to work with.
just do yourself a favor and treat yourself to some citric acid:



on amazon, it's like $10 for 1lb, $13 for 2lb, $15 for 5lb, or $25 for 10lb.
i say just get a 2lb or 5lb bag of it.
i bought 2lb a couple of years ago, and i still have most of it left. i use it for descaling and occasionally in cooking (sauce and jam making).
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pedant
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Thu Aug 27, 2020 10:12 pm

OhThatNinja wrote:
Sun Aug 02, 2020 6:37 pm
after four boiling sessions with baking soda and citric acid (I used lemon juice) alternating them, most of the stains came off!
i really do not recommend using lemon or lime. why risk contamination with citrus oils? i know it worked out for you, and i'm not trying to admonish. i'm just saying to future readers that i don't think it's a good idea.

just like using soap is a bad idea.
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Bok
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Thu Aug 27, 2020 11:46 pm

Citric acid in Chrystal form is absolutely no problem, I’ve used it many times.

I wouldn’t use lemon juice either.
gregcss
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Fri Aug 28, 2020 3:17 pm

@pedant Thanks for the advice. I will defer to using crystallized citric acid.
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OCTO
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Sat Aug 29, 2020 12:37 am

pedant wrote:
Thu Aug 27, 2020 10:12 pm
OhThatNinja wrote:
Sun Aug 02, 2020 6:37 pm
after four boiling sessions with baking soda and citric acid (I used lemon juice) alternating them, most of the stains came off!
i really do not recommend using lemon or lime. why risk contamination with citrus oils? i know it worked out for you, and i'm not trying to admonish. i'm just saying to future readers that i don't think it's a good idea.

just like using soap is a bad idea.
@OhThatNinja

I agree with @pedant and @Bok. Why risk contamination and leaving behind a long and nagging smell?... I personally use oxygen based stain removers which are non toxic to our body. Been getting pretty good results and it is completely odourless.

Cheers!!

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