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Hey everyone. I was looking for some kind of grit to add to my clay for aesthetic reasons. So I went ahead and bought some grog but I also bought a sack of chicken scratch. It's 100 percent calcium. Pebble sized and didn't dissolve in water, made for an interesting throw.  What should I expect firing wise (^6 ) ?  

Edited by BlackDogPottery

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Calcium based chicken scratch is going to behave as seashells do in the firing which is not going to behave at all like the granite based chicken scratch. Article from Rimas VisGirda here, he discusses using granite, decomposed granite and other inclusions he uses. 

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Min and Chris,

Thanks for the links and pictures. Very interesting work and information.

Blackdog, are you going to be incorporating this into your work with the dark slip? I can't wait to see that combo if you are. Where did you get the calcium chicken grit from? I tried googling it but I didn't find any good sources locally.

Edit: Never mind I found a local source. I was looking in the wrong places.

Edited by Joseph F

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On 12/29/2017 at 2:47 PM, Joseph F said:

Min and Chris,

Thanks for the links and pictures. Very interesting work and information.

Blackdog, are you going to be incorporating this into your work with the dark slip? I can't wait to see that combo if you are. Where did you get the calcium chicken grit from? I tried googling it but I didn't find any good sources locally.

Edit: Never mind I found a local source. I was looking in the wrong places.

I got mine at a Tractor Supply as well as the granite.

It didn't work at all! After firing the grit had become almost chalk. When I started rinsing it off the grit absorbed the water and expanded. Broke apart the pot and knocked the glaze off. There wasn't much left but a sink of milky water, flakes of glaze, and crumbles of a pot!

Edited by BlackDogPottery

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look for the chicken grit that specifically says granite. i've used it and it just stands out up on the walls. you cant really see it in bisqueware, but it shows thru after glaze firing.  i've done ^6 and ^7 glaze firing and ^10 soda fire (but i think it didnt go past ^8)

Rimas VisGirda has a very good article about additions called Let it Bleed.  he though talks about feldspar.  the free article does not have pictures. the pictures are very helpful to understand.  <duh the article min posted>

i think the granite chicken girt has feldspar.  though you can also buy custer feldspar in different sizes from home depot (as i've been told). 

HOLY COW!!! so sorry dont know how to reduce the size of the picture. 

Image result for chicken grit granite

Edited by preeta

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@preeta I am using a Mac, so the click+drag does not work for me, and I don't have a right mouse button. I can double click an image, which gives me a pop-up window that allows me to change the size.

On my iPad I cannot adjust a picture size at all. I can only do it from my laptop. 

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joel, the website has a limit on the number of something or others that pictures eat up.   that is why marcia selsor uses tiny pictures, usually smaller than a thumbnail.  at some point the website will refuse to allow another picture.  i found this out last year and discovered that the limit is for a calendar year.  so, if you reach that limit and wait a few days, you can post another one.

OR, just become a new member with the same name and the number 2.  that way you get a whole new clean slate.:rolleyes:

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I remember there used to be a limit on how much you could upload but I also remember the number changing to say 'unlimited' in my gallery at some point from whatever value it was in the first place.

Not sure what happened after they updated the forum as I can't see a limit stated anywhere in the gallery.  I think the picture above is linked from amazon so not stored on the forum.

Edited by High Bridge Pottery

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I am going to pickup a bag of that MannaPro crushed granite tomorrow morning. I will post results when I finally get around to actually making something in this freezing cold weather. Spring please? Plus if I ever get chickens they can scratch through the pottery shards and get the grit out like little miners.

On a side note I love chickens. I am going to put some golden chicken decals on some of my newer work. BINGO!

Edited by Joseph F

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On 1/5/2018 at 1:16 PM, oldlady said:

joel, the website has a limit on the number of something or others that pictures eat up.

It has to do with the image's file size. Right now there is a 48.83 MB limit.  One MB is 1024k, if your image files are 100k in size you can upload 500 images, if your images file are 1MB in size you can upload 48.8 images. Most of my image files uploaded here are between 36k and 70k

Before the move to the new forum there was an option to delete  your images to free up some space if you needed it, that option is no longer available.

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Well, I threw some pots today for the first time in a good 30-45 days. I added red sand, beach sand, chicken grit and course grog. I weighed my clay after I added the materials. It went from 2# to 2.5#. So I definitely added a lot of materials to it. I threw a few cups and some test stuff and I made a bunch of tiles.

Throwing with the grit is interesting. I think my hands enjoyed the exfoliation. But if this is to continue I will need to start using sponges to center. I have done this before so it won't be a big deal. I really like how when I run a trimming tool over it on the wheel wet it peels back large gaps in the body of work. I can't wait to see how it shrinks and the grit cracks or start popping out. I don't know how long it will be until I get to fire it, but I will post results.

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Thank you all for the heads up about resizing pictures. i'll know the next time if i was successful.

Wow Joseph you tried a lot in your clay.  Am curious to know what were you hoping to achieve all the sands and grog? was it fine grog ?

Please update after your glaze firing too. i'd like to see if there was pitting. One of our 4 year college students said he stopped using chicken grit because he felt the ingredients list was not honest and he had too many cracking and glaze issues. 

Thought you might enjoy this article. https://ceramicartsnetwork.org/pottery-making-illustrated/article/shigaraki-surfaces/#

One of the things i want to try this time is coat the feldspar with either copper or cobalt , bisque it (cant think of the right terminology) and then add it to the clay as  Rimas tried.

I've tried various sands and fine grog  (what they had in school) and i wasnt impressed with ^6 firing. i made vases.  some areas were rough otherwise it just made my surface appear peppered. 

i'd love to try rough clay surface, but i havent been able to come up with the right glaze to use on it.  

however those surfaces looked fantastic in soda with and without glaze. 

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The following assumes that the reason for adding 'stuff' to the clay body is for decorative effects:
 
Instead of adding grit to the entire clay body,  just make a thick slip or paste using the regular clay body to which the 'chicken scratch' or any other material such as rice, crushed river rocks, metal filings, ... is added.  The 'slip/paste' is then used coat the designated surfaces.  Application can be by brushing, thin slabs, sprigging, pouring, etc.  Compression of the applied layers of 'slip/paste' is recommended to insure adhesion to the substrate.
 
The process allows the one to try various 'additives' to the clay body without having to deal with the forming or maturing of the main substrate of the ware being made.  The 'slip/paste' can be applied selectively to areas where needed to create the visual or tactile surfaces of the design.   After application of the 'slip/paste' the coating can be carved to produce sgraffito-like contrasts between the coating and the substrate color/texture.   Paper resists also can produce surface contrasts.
 
I have used this concept on cone 10 ware with high technical success using various sands, crushed iron nodules, chopped pine needles, sawdust, rice, crushed bisque, coarse fire clays, and garden dirt.  The aesthetic success rate is moderate.  Some forms are enhanced and others are deteriorated.   
Some additives I have not tried that might work are: crushed glazed ware, dried glaze lumps from left over glazes or hard pan muck from the bottom of a glaze bucket, crushed glass bottles, raisins, and chicken scratch.  The main constraint is that the combustibles should burnout during the bisque step and any meltable components should NOT melt during bisque step.  
As the ad said 50 years ago: "Try it. You'll like it!"
 
LT
 
 

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On January 11, 2018 at 3:03 PM, Joseph F said:

Well, I threw some pots today for the first time in a good 30-45 days. I added red sand, beach sand, chicken grit and course grog. I weighed my clay after I added the materials. It went from 2# to 2.5#. 

Joseph:

one thing to remember: the more large particle additions you make: the  greater the porosity of the  body. If you run into weeping issues, then you will have to make fine particle additions to close up the pores.

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OH LT you just blew my mind. adding the stuff to slip!!! that's BRILLIANT!!! plus the weeping issues wont happen.  and then to paint with texture rather than colour. wow that just opens a whole new door for me. 

i really like your thinking about the pan muck and glaze clumps. even with ^6 i think i can experiment at school since they only bisque to  010.

i love experimenting. its what keeps me going. 

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As promised here are the results of my additions of chicken grit. I am pretty satisfied with them. These have no glaze as I wanted to see the surfaces.

5a66187962629_MVIMG_20180122_115501(Copy).jpg.0f9760f50b2bf99e719c5099e4e9651b.jpg5a6618828ccd5_MVIMG_20180122_115516(Copy).jpg.9d9697726c7a35b9754a9cdfe81e8bf5.jpg

5a66188aade73_MVIMG_20180122_115529(Copy).jpg.14987fb7d2b843813c38a24814ef167b.jpgCapture.JPG.45c5778b7c9297cb326a310d9c422605.JPG

 

5a66188fc2be2_MVIMG_20180122_115550(Copy).jpg.951e1d26e22582425111057aac00fb7a.jpg

The tiles are for comparison of the mixtures of the clay bodies for myself, but I thought they were interesting to see visually. 

The close up of the vase shows how awesome the grit does at cracking the surface. I really like that. Thanks for the chicken grit idea. 

Edited by Joseph F
close up

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