Terra Cotta: My musings on...and resulting actions with.

[HorseloverFat]

Thank you! I appreciate input!
Interesting... would I just flux it to my “needs” like i would ball clay or kaolin additives to my body? I fire 06-08. “Soup-making” - Temps.

 

[NaoTK]

I read that kyanite doesn't add crystal strength until cone 14, so I have been using mullite/kyanite.

Sorce

That may be true. Well, kyanite makes up a huge part of raku bodies which are low fired. I imagine they take advantage of kyanite's expansion in that range to reduce cracking and thermal shock

 

[HorseloverFat]

That may be true. Well, kyanite makes up a huge part of raku bodies which are low fired. I imagine they take advantage of kyanite's expansion in that range to reduce cracking and thermal shock

Cool! Thank you!

 

[sorce]

That may be true. Well, kyanite makes up a huge part of raku bodies which are low fired. I imagine they take advantage of kyanite's expansion in that range to reduce cracking and thermal shock

That's what my guy gave me kyanite for at first, which made me read.
There may be something still to the thermal shock properties, but the way I understood the information, was that it wasn't effective until high temps, that the crystals are what allows the properties to be.

As simply a fine grog, without reaction, I can see it helping still.

Buttloads seems too much!lol I guess some rectums are bigger than others!

In Standards required but not exactly published materials %'s, mullite is listed as near 1% of almost every clay. So I have been substituting roughly 25% of the total grog content with mullite/kyanite.

I use some recipes with grog included in the 100, and some with it added after, like a glaze colorant %. 100 + x grog.

That thin walled Copper Red joint from my buff body that tested out at almost 2%absorption, WITH a crack at the lip top already, is second from the right.


I packed em with muddy soil sure to crack em in the freeze. And they been through a dozen freeze thaws already! Still Good!

Mellow Mullite!

Chi-Town Tough.

Sorce

 

[HorseloverFat]

That's what my guy gave me kyanite for at first, which made me read.
There may be something still to the thermal shock properties, but the way I understood the information, was that it wasn't effective until high temps, that the crystals are what allows the properties to be.

As simply a fine grog, without reaction, I can see it helping still.

Buttloads seems too much!lol I guess some rectums are bigger than others!

In Standards required but not exactly published materials %'s, mullite is listed as near 1% of almost every clay. So I have been substituting roughly 25% of the total grog content with mullite/kyanite.

I use some recipes with grog included in the 100, and some with it added after, like a glaze colorant %. 100 + x grog.

That thin walled Copper Red joint from my buff body that tested out at almost 2%absorption, WITH a crack at the lip top already, is second from the right.
View attachment 346452

I packed em with muddy soil sure to crack em in the freeze. And they been through a dozen freeze thaws already! Still Good!

Mellow Mullite!

Chi-Town Tough.

Sorce

That’s TASTY stuff right there!

(The info and pots..... not the rectums)

 

[sorce]

That’s TASTY stuff right there!

(The info and pots..... not the rectums)

Man! These pots are like ......so close to being perfect!
At least if they come through the winter I can sell them confidently as useable seconds.

It's frustrating as hell when beautiful things, perfect for trees, have slight dumbass cracks, unseen when planted, that are .... basically useless.

Leaving em out this winter has my confidence going through the ....failing ozone layer! Lol!

Sorce

 

[HorseloverFat]

Man! These pots are like ......so close to being perfect!
At least if they come through the winter I can sell them confidently as useable seconds.

It's frustrating as hell when beautiful things, perfect for trees, have slight dumbass cracks, unseen when planted, that are .... basically useless.

Leaving em out this winter has my confidence going through the ....failing ozone layer! Lol!

Sorce

I left one of my earlier pieces out.. with soil, moss, and blisterwort.. not because I love blisterwort.. but to see how it holds up to my winters.. so far.. it looks identical.. but it’s early.

 

[NaoTK]

In Standards required but not exactly published materials %'s, mullite is listed as near 1% of almost every clay. So I have been substituting roughly 25% of the total grog content with mullite/kyanite.

I use some recipes with grog included in the 100, and some with it added after, like a glaze colorant %. 100 + x grog.

Interesting, what % grogs are you playing with? I often use 25% as an addition. Or sand while we are on the topic? I haven't used mullite, will give it a try. What I gather is, you may not see any benefit from either additive unless it's a butt load (10-25% depending on butt)

 

[HorseloverFat]

Interesting, what % grogs are you playing with? I often use 25% as an addition. Or sand while we are on the topic? I haven't used mullite, will give it a try. What I gather is, you may not see any benefit from either additive unless it's a butt load (10-25% depending on butt)

I’ve dabbled heavily in sand clay Or utilizing sand to fill out certain parameters... in seemingly endless variations with my red/crimson earthenwares... black sands are neat to play with. So are white sands with natural crushed shells.. tan/brown sands need rinsing, blah-yadda-cetera. If you are NOT using the sand as your MAIN temper/conponent.. particle size is important in it’s consistency...
But the MAJORITY of batches/recipes i have been working with have a notable sand component..
But if “sand clay batch” is my goal.. i’m more free with the particulate size..

It’s also real hard on the hands..

The last experimental SAND clay batch I did... I had purposefully pushed the sand component too far... then made a separate low-fire loose body/paste from Ball clay/calcium bentonite/talc (mostly).. then mixed back in, in workable increments until I could start “sweating the balls” , wedging and checking for desired plasticity.

 

[sorce]

% grogs

These are recipes from a book, modified to use what I have, with local materials added.

This is the buff.


The one @RJG2 goldflexed. This is the one with grog In the 100, it was 10 (Red Brick Grog), for which I substituted half coarse grog and half silica sand.


This is the one that broke at cone 7 maybe 8, the corner from a couple pages back. A 2 clay combo. No good....ish.


Sorce

 

[RJG2]

The one @RJG2 goldflexed. This is the one with grog In the 100, it was 10 (Red Brick Grog), for which I substituted half coarse grog and half silica sand.
View attachment 346489

Yeah, I understood all that...

For reference:

 

[sorce]

Thanks @RJG2 , I can't get over how dope that looks!

That is also the pot, all hand formed, due to that coarse grog.

Sorce

 

[HorseloverFat]

Thanks @RJG2 , I can't get over how dope that looks!

That is also the pot, all hand formed, due to that coarse grog.

Sorce

That coarse grog.. is strange to work with.. broke one of my knives... now I just use ceramic knives or reeeal thin sheets for “the cuttin’

Never returned to coarse grog.. but it’ll wind up in my “ingredients” again.. last i looked.. the LAST batch of clay i made was number 37 (Since i started actually MAKING “recipes”.. not crudely mixing...)... SO much to show for that... in knowledge.. not finished work.

 

[RJG2]

Thanks @RJG2 , I can't get over how dope that looks!

That is also the pot, all hand formed, due to that coarse grog.

Sorce

Not bad for a first try, but all credit goes to @ABCarve - his threads are always very knowledgeable - I feel like I'm almost ready to build a wet slab next

 

[HorseloverFat]

wet slab

That’s a GREAT thread.

 

[ABCarve]

Thanks RJG2 for showing me this thread. Interesting stuff. I’m not into mixing my own clay bodies but I have put copious amounts of grog into some of the Standard clays that I use. I would imagine 40-50%. The pots all came out fine and I’ve used them through multiple winters. They’re my Neolithic Groglodyte series. Standard makes one that is like using mortar mix and has an absorption of .75.

 

[HorseloverFat]

40-50%.

WOWZERS! If i used that much grog for my methods.. there’d be blood in the clay body too!

(I do know WHY, though.. Like I said, I’m familiar with your spectacular “press” work)

 

[HorseloverFat]

Do you guys make your own oxides and whatnot?... or am I just nuts?

Here’s my most recent experiment.. attempting to extract Ni and NOT Cu from these coins... the first couple were unsuccessful... but with THIS “try” (order of events and acids/spirits) is working to throw soluble Nickel into my “solution”.... now just salt-oxidation is left before I can see “what’s up”
I normally don’t “buy” anything that is within my power/realistic resources to “fabricate”... but this STARTED from necessity.

 

[sorce]

own oxides

I scraped some beautiful Iron off of the BBQ rack that ended up on a pot.

More fun than that was this rock I found, black iron core with a red oxidized layer on top, it was perfectly smooth for burnishing and would leave a layer of Iron too.
Look for rocks.

You ever take a UV light and look for those glowing rocks?

Sorce

 

[HorseloverFat]

I scraped some beautiful Iron off of the BBQ rack that ended up on a pot.

More fun than that was this rock I found, black iron core with a red oxidized layer on top, it was perfectly smooth for burnishing and would leave a layer of Iron too.
Look for rocks.

You ever take a UV light and look for those glowing rocks?

Sorce

Hehe! I have a bunch of steel currently oxidizing.. I also collect “slag”, and go “rick hunting” quite frequently. (I know it says Rick.. I’m leaving it ) Also made some very crude cupric acid...