What is wrong with this pot?

[LittleBigOwl]

So today i had to break the terracotta pot from HomeDepot cause it cracked and here is what i found inside. I have already asked multiple people and some of them are saying that this is cement, others suggested that this is just some sort of unfired clay that is inside (but why is it black?)
Any ideas or maybe somebody knows for sure what this is.

[DirtyCoconuts]

not uncommon to see..i always assumed they used a cheaper base clay that didn't turn in the firing

[JScott]

Yeah, there's nothin wrong with your pots, that's just how a lot of them are made now. It is probably an economical decision. The center material is probably less espensive that the terra cotta. The pots still work the same an allow air flow and gas exchange, so I don't think it's anything to worry about.

[LittleBigOwl]

Originally Posted by JScott

Yeah, there's nothin wrong with your pots, that's just how a lot of them are made now. It is probably an economical decision. The center material is probably less espensive that the terra cotta. The pots still work the same an allow air flow and gas exchange, so I don't think it's anything to worry about.

Thanks! Aeration was my biggest concern about them

[DirtyCoconuts]

it might be slower or faster than a traditional Italian pot but they wick and breath all the same

[Ray]

As the Orchid Board's resident ceramic engineer, I can tell you it all has to do with the firing cycle.

The oxidation state of the iron oxide in the clay can change color depending upon the firing atmosphere, turning red, black, and green (think Coca-Cola bottles).

With excess fuel (likely natural gas) poured into the kiln, it is reduced and a black color. After the flame is extinguished and the clay is allowed to cool (slowly, to prevent cracking) the fuel-lean atmosphere is oxidizing. As the oxygen penetrates the porous clay body, it turns "orange" from the outside in.

Apparently, in the case of that pot, the entire thing cooled enough that the iron wasn't thermally energetic enough to fully oxidize in the interior.

[LittleBigOwl]

Originally Posted by Ray

As the Orchid Board's resident ceramic engineer, I can tell you it all has to do with the firing cycle.

The oxidation state of the iron oxide in the clay can change color depending upon the firing atmosphere, turning red, black, and green (think Coca-Cola bottles).

With excess fuel (likely natural gas) poured into the kiln, it is reduced and a black color. After the flame is extinguished and the clay is allowed to cool (slowly, to prevent cracking) the fuel-lean atmosphere is oxidizing. As the oxygen penetrates the porous clay body, it turns "orange" from the outside in.

Apparently, in the case of that pot, the entire thing cooled enough that the iron wasn't thermally energetic enough to fully oxidize in the interior.

Ray thanks a lot! I really appreciate your help with solving this mystery (well for me it was a mystery).

[JScott]

Originally Posted by Ray

As the Orchid Board's resident ceramic engineer, I can tell you it all has to do with the firing cycle.

The oxidation state of the iron oxide in the clay can change color depending upon the firing atmosphere, turning red, black, and green (think Coca-Cola bottles).

With excess fuel (likely natural gas) poured into the kiln, it is reduced and a black color. After the flame is extinguished and the clay is allowed to cool (slowly, to prevent cracking) the fuel-lean atmosphere is oxidizing. As the oxygen penetrates the porous clay body, it turns "orange" from the outside in.

Apparently, in the case of that pot, the entire thing cooled enough that the iron wasn't thermally energetic enough to fully oxidize in the interior.

Sometimes it absolutely blows my mind the things that you just know. I mean, I am knowledgeable about a lot of topics, and I know some obscure things that other people probably don't, but the sheer volume of your obscure knowledge just thrills me. I love it when you post stuff like this.

[DirtyCoconuts]

Originally Posted by JScott

Sometimes it absolutely blows my mind the things that you just know. I mean, I am knowledgeable about a lot of topics, and I know some obscure things that other people probably don't, but the sheer volume of your obscure knowledge just thrills me. I love it when you post stuff like this.

HAHAHA me too!

I was raised in a family where being smart was the coolest thing....when i was a senior in high school i was named a third string all state lacrosse player, no one in my family has ever done anything physically exceptional and no one cared because my brother, who was in 5th grade won his spelling bee the same day it was announced

smart people RULE

[JScott]

Originally Posted by DirtyCoconuts

HAHAHA me too!

I was raised in a family where being smart was the coolest thing....when i was a senior in high school i was named a third string all state lacrosse player, no one in my family has ever done anything physically exceptional and no one cared because my brother, who was in 5th grade won his spelling bee the same day it was announced

smart people RULE

My brother and i are both smart and it was always a competition to see who was smarter. He was two years older than me, so two grades ahead. He kept all his report cards so that when I finally took whatever class two years later, he would know which once of us had won hahahahaha. Sometimes I was even the winner! He went on to major in chemistry, and I majored in Classics with emphasis in Latin language, both notoriously difficult majors. I think we both did pretty well for ourselves. But neither of us had an athletic bone in our body hahaha.

Your story about the spelling be is both hilarious and sad lol. But you're one my most trusted and respected people on this forum, so I think you've got it going on. And Ray, it always makes me nervous when he comments right after me. I love it when he agrees with me, I feel so validated, but occasionally he does not agree, and I get that same feeling I used to get when my favorite professor would ask a question and I would raise my hand to answer, and then I got it wrong lol.