Is Yixing more porous than CZ??

[steanze]

and maybe another:

https://www.onepetro.org/conference-paper/SPE-178296-MS

I think all the articles so far say there is a correlation between grain size and porosity, but they say smaller size is greater porosity (i think).
now thinking about is , smaller size can mean greater porosity. Even if the particle is smaller it means now there are more particles, each of which are still porous on their own, so when you put more particles together you have greater total porosity (i think).

ill keep looking into it.

thanks

I am afraid the relationship is complex. For example "Theoretically, grain size does not affect porosity for well sorted grains but in nature, sand grain size affects porosity probably because sand grain deformation from a spherical shape increases with decrease in particle size. " Now, different kinds of clay might have different deviations from sphericity of their grains.

Note that this relationship between grain size and porosity in the articles is tested holding the composition of the material constant. In teapots, the composition of clays varies widely. Composition can affect porosity. Materials with the same grain size but different composition can have different sized pores.

[Trusar]

and maybe another:

https://www.onepetro.org/conference-paper/SPE-178296-MS

I think all the articles so far say there is a correlation between grain size and porosity, but they say smaller size is greater porosity (i think).
now thinking about is , smaller size can mean greater porosity. Even if the particle is smaller it means now there are more particles, each of which are still porous on their own, so when you put more particles together you have greater total porosity (i think).

ill keep looking into it.

thanks

I am afraid the relationship is complex. For example "Theoretically, grain size does not affect porosity for well sorted grains but in nature, sand grain size affects porosity probably because sand grain deformation from a spherical shape increases with decrease in particle size. " Now, different kinds of clay might have different deviations from sphericity of their grains.

Note that this relationship between grain size and porosity in the articles is tested holding the composition of the material constant. In teapots, the composition of clays varies widely. Composition can affect porosity. Materials with the same grain size but different composition can have different sized pores.

yeah that article was about sand i think, but the other two were about clay. what about the first article? the second one is in depth, hard to understand and long to read. i tried to skip to the conclusion at the end but was unable to understand, theres too much to read, ill keep looking. thanks for the response.

[steanze]

yeah that article was about sand i think, but the other two were about clay. what about the first article? the second one is in depth, hard to understand and long to read. i tried to skip to the conclusion at the end but was unable to understand, theres too much to read, ill keep looking. thanks for the response.

You are welcome! Another thing to consider is that shrinkage during firing in the kiln affects porosity too. And shrinkage itself is affected by the chemical composition (i.e. iron content of the clay, ...).

[Trusar]

yeah that article was about sand i think, but the other two were about clay. what about the first article? the second one is in depth, hard to understand and long to read. i tried to skip to the conclusion at the end but was unable to understand, theres too much to read, ill keep looking. thanks for the response.

You are welcome! Another thing to consider is that shrinkage during firing in the kiln affects porosity too. And shrinkage itself is affected by the chemical composition (i.e. iron content of the clay, ...).

ok according to YS website:

- "this clay contains very high amount of iron oxide"
- "The finer the clay used the more sheen the pot has"
- "The clay is highly porous but without allowing water to escape or soak in deeply. "

you said your teapot, sweats out the water from the inside to the outside. so far this is the best description for a fully porous clay pot. half porous would probably just be muting without sweating because is gets absorbed from the inside but doesn't quite get as far as the outside.
According to YS the water doesn't soak in deeply or escape (dont know what they mean by escape). so then how is exactly is it highly porous? (if you know). if anything there saying its highly porous, but giving a reason as to why its not highly porous.
maybe the iron oxide somehow plays a factor.

the YS pot i have does not sweat or mute. the most it does is have react with some teas.

[Trusar]

ill post back once ive been to postcard teas and also emailed YS about this pot i bought from them.

[Trusar]

yeah that article was about sand i think, but the other two were about clay. what about the first article? the second one is in depth, hard to understand and long to read. i tried to skip to the conclusion at the end but was unable to understand, theres too much to read, ill keep looking. thanks for the response.

You are welcome! Another thing to consider is that shrinkage during firing in the kiln affects porosity too. And shrinkage itself is affected by the chemical composition (i.e. iron content of the clay, ...).

ok according to YS website:

- "this clay contains very high amount of iron oxide"
- "The finer the clay used the more sheen the pot has"
- "The clay is highly porous but without allowing water to escape or soak in deeply. "

you said your teapot, sweats out the water from the inside to the outside. so far this is the best description for a fully porous clay pot. half porous would probably just be muting without sweating because is gets absorbed from the inside but doesn't quite get as far as the outside.
According to YS the water doesn't soak in deeply or escape (dont know what they mean by escape). so then how is exactly is it highly porous? (if you know). if anything there saying its highly porous, but giving a reason as to why its not highly porous.


the YS pot i have does not sweat or mute. the most it does is have react with some teas.

oh sorry that post was suppose to be for Baisao.

[steanze]

ok according to YS website:

- "this clay contains very high amount of iron oxide"
- "The finer the clay used the more sheen the pot has"
- "The clay is highly porous but without allowing water to escape or soak in deeply. "

you said your teapot, sweats out the water from the inside to the outside. so far this is the best description for a fully porous clay pot. half porous would probably just be muting without sweating because is gets absorbed from the inside but doesn't quite get as far as the outside.
According to YS the water doesn't soak in deeply or escape (dont know what they mean by escape). so then how is exactly is it highly porous? (if you know). if anything there saying its highly porous, but giving a reason as to why its not highly porous.
maybe the iron oxide somehow plays a factor.

the YS pot i have does not sweat or mute. the most it does is have react with some teas.

If someone has a large western-facing store, it does not mean s/he is an expert on everything s/he sells. This statement: "The finer the clay used the more sheen the pot has" is incorrect (maybe there was more context that has been cut). I have coarse clay pots that pick up more sheen than finer clay pots. The development of patina does not depend only on the clay's grain. I think it is a good strategy to evaluate how expert a source is before going with what they say. For example, you can ask: 1) does this person show evidence of being able to authenticate old pots (F1 and earlier)? 2) does this person have antique teapots? (not necessary, but usually having them requires knowing a thing or two and it means they have had the opportunity to study them), 3) has this person published work on yixing teapots, or is s/he recognized in the community as a knowledgeable person on the topic? These are much better indicators for a person you want to learn from than owning a large store.

For example Dr Lv, Kyarazen, Teaism, OCTO, are people who know a lot. And Baisao, Bok, Chadrinkincat also know things and are careful in their evaluations. (and I'm sure there are a lot of other people that aren't coming to mind right now).

[Baisao]

ok according to YS website:

- "this clay contains very high amount of iron oxide"
- "The finer the clay used the more sheen the pot has"
- "The clay is highly porous but without allowing water to escape or soak in deeply."

you said your teapot, sweats out the water from the inside to the outside. so far this is the best description for a fully porous clay pot. half porous would probably just be muting without sweating because is gets absorbed from the inside but doesn't quite get as far as the outside.

According to YS the water doesn't soak in deeply or escape (dont know what they mean by escape). so then how is exactly is it highly porous? (if you know). if anything there saying its highly porous, but giving a reason as to why its not highly porous.
maybe the iron oxide somehow plays a factor.

the YS pot i have does not sweat or mute. the most it does is have react with some teas.

There are many factors at play. For example, if the shudei teapot had been fired at a higher temperature, it might no longer weep. The silica and other components of the clay might vitrify in such a way that it could not weep. It is stoneware, but it is possible that it could change its internal structure under a higher temperature.

The point of the shudei example was to show a glossy pot, with a smooth finish, that is nevertheless extremely porous.

I think that there are many variables involved that makes it difficult to make an absolute from a generalization. As we’ve been discussing the affect of porosity on tea, we have not discussed the one generalization all of my teachers have said is the reason CZ teapots affect tea: they are wheel thrown rather than slab built!

I have no way to prove my teachers are correct about this but they would tell me, consistently, to add an extra gram of tea to a CZ teapot compared to a F1 hongni teapot of the same size.

I know this muddies things. I am sorry. But it should show you that there are many things going on here, and some of them are just passed along generalizations.

Cheers!

[Chadrinkincat]

@steanze Lol. Surprised I had an honerable mention on that list. I wish I had the level of knowledge that others on that list possess. I’ve still got a long way to go on my collectors journey.

I do agree with your accessment on vendor knowledge.

[Bok]

@steanze you humbly forgot to include yourself, which I hereby do!

I myself count myself merely an apprentice of the firstly mentioned…

Yet what I can say, most things can only be learned, when you can see and touch the real thing in your hands. Afterwards it gets a tiny bit easier to judge from imagery, but still, most remains speculation unless seen and tested in person.

So Steanze is right, trust the ones who have a proven track record in the community.
Most vendors do first and foremost sell tea, which does not automatically make the experts on tea ware.

Vendors only selling tea ware on the other hand, often do have other interests as well, 100% true information often not one of them, especially if they sell antiques and vintage.

[Baisao]

steanze you humbly forgot to include yourself, which I hereby do!

I myself count myself merely an apprentice of the firstly mentioned…

Yet what I can say, most things can only be learned, when you can see and touch the real thing in your hands. Afterwards it gets a tiny bit easier to judge from imagery, but still, most remains speculation unless seen and tested in person.

So Steanze is right, trust the ones who have a proven track record in the community.

Most vendors do first and foremost sell tea, which does not automatically make the experts on tea ware.

Vendors only selling tea ware on the other hand, often do have other interests as well, 100% true information often not one of them, especially if they sell antiques and vintage.

I second all of this!

[OCTO]

steanze you humbly forgot to include yourself, which I hereby do!

I myself count myself merely an apprentice of the firstly mentioned…

Yet what I can say, most things can only be learned, when you can see and touch the real thing in your hands. Afterwards it gets a tiny bit easier to judge from imagery, but still, most remains speculation unless seen and tested in person.

So Steanze is right, trust the ones who have a proven track record in the community.

Most vendors do first and foremost sell tea, which does not automatically make the experts on tea ware.

Vendors only selling tea ware on the other hand, often do have other interests as well, 100% true information often not one of them, especially if they sell antiques and vintage.

I second all of this!

This is getting fun!! I third all of the above!!

Cheers!!

[Trusar]

I was thinking of emailing them and asking.

think its a good idea?

if so i was going to say something along the lines of what makes this tea pot porous? or why is it porous? (CZ hongni i bought of him). what exactly does it do that makes it porous?
because from my experience and according the the website it doesn't absorb moisture (and then sweat it out) and it doesn't mute any of the teas, all it does do is conduct heat effectively and maybe react very well with some teas.

[Trusar]

ok according to YS website:

- "this clay contains very high amount of iron oxide"
- "The finer the clay used the more sheen the pot has"
- "The clay is highly porous but without allowing water to escape or soak in deeply. "

you said your teapot, sweats out the water from the inside to the outside. so far this is the best description for a fully porous clay pot. half porous would probably just be muting without sweating because is gets absorbed from the inside but doesn't quite get as far as the outside.
According to YS the water doesn't soak in deeply or escape (dont know what they mean by escape). so then how is exactly is it highly porous? (if you know). if anything there saying its highly porous, but giving a reason as to why its not highly porous.
maybe the iron oxide somehow plays a factor.

the YS pot i have does not sweat or mute. the most it does is have react with some teas.

If someone has a large western-facing store, it does not mean s/he is an expert on everything s/he sells. This statement: "The finer the clay used the more sheen the pot has" is incorrect (maybe there was more context that has been cut). I have coarse clay pots that pick up more sheen than finer clay pots. The development of patina does not depend only on the clay's grain. I think it is a good strategy to evaluate how expert a source is before going with what they say. For example, you can ask: 1) does this person show evidence of being able to authenticate old pots (F1 and earlier)? 2) does this person have antique teapots? (not necessary, but usually having them requires knowing a thing or two and it means they have had the opportunity to study them), 3) has this person published work on yixing teapots, or is s/he recognized in the community as a knowledgeable person on the topic? These are much better indicators for a person you want to learn from than owning a large store.

For example Dr Lv, Kyarazen, Teaism, OCTO, are people who know a lot. And Baisao, Bok, Chadrinkincat also know things and are careful in their evaluations. (and I'm sure there are a lot of other people that aren't coming to mind right now).

no that was the entire line, maybe they are referring to just CZ clay rather than all clay types.
heres the whole paragraph:

"Feng Xi area near Chaozhou (in Guangdong) is where the clay is mined. It's a mountainous area and the clay mined there is very fine and is easy to work when it's mixed with water. Typically the clay is worked on a wheel. Chaozhou Hong Ni after firing takes on a deep red-orange color and a natural sheen. The finer the clay used the more sheen the pot has. The clay has a very high level of iron oxide, it's very pliable and after firing contracts about 15%. Firing temperatures used in the local kilns are close to 1000 celsius."

You said your corse pot had picked up a sheen, does that mean when it was unused it did not have a sheen?
I have a coarse zini, and it has the same/similar sheen to the CZ i have. The only difference is i had season the outside of the zini, but the CZ was like that when i got it.

teahabitat actually as a pot made by the same maker, zhang lin hao, and the teapot was available at YS but is now sold out. on Teahabitat it says to use it for sheng and be prepared to be surprised. i might try this. if it somehow takes the astringency away then......

how do i unseason a teapot? if i try it with sheng ill need to remove all the sheng out of the pores in the teapot just incase it doesnt work out, and i dont want to keep mixing teas in it just in case.

thanks

[Trusar]

I was thinking of emailing them and asking.

think its a good idea?

if so i was going to say something along the lines of what makes this tea pot porous? or why is it porous? (CZ hongni i bought of him). what exactly does it do that makes it porous?
because from my experience and according the the website it doesn't absorb moisture (and then sweat it out) and it doesn't mute any of the teas, all it does do is conduct heat effectively and maybe react very well with some teas.

actually i might just ask tea habitat, or i can ask both, now that i know they both have used this teapot maker zhang lin hao.