Morgan

Hi Morgan 
No I never got into the habit of wiping my pieces down before glazing as I’m usually in such a rush to get things in the kiln. This was some time ago when I used to work in a studio and the piece didn’t reach full temp so I refired it and this is what happened. I reckon I contaminated it with moving it from A to B but will take more care in the future. I thought it was something to do with firing it twice! 

I don’t believe I have his number but I will double check our email chains. I am thinking health as well and hope he is ok. That was also another reason I posted as I figured someone here might know. 
 
If someone has it and wouldn’t mind sharing ( @Roberta12 ?) it and can message me that would be great. 

Super hard for me to see the pics are small to my eyes but looks like it could just me as simple as brushing on a white matte glaze unevenly/thin/thick and maybe a brushed cobalt wash? Could be underglaze but seems more like a wash from afar. 

Super hard for me to see the pics are small to my eyes but looks like it could just me as simple as brushing on a white matte glaze unevenly/thin/thick and maybe a brushed cobalt wash? Could be underglaze but seems more like a wash from afar. 

Super hard for me to see the pics are small to my eyes but looks like it could just me as simple as brushing on a white matte glaze unevenly/thin/thick and maybe a brushed cobalt wash? Could be underglaze but seems more like a wash from afar. 

Ya it all dried just the same. I am used to color being a bit off but frost is so freaking white it’s just much more obvious. I did throw some test tiles with my first reclaim and it seemed just as slippy as fresh so we shall see. That said I don’t see myself making many large serving plates with it :)

Ok thanks all for that info that is invaluable. Right now my plan and process has been saving every drop of throwing slurry I can and mix that with dry scraps and water as needed. In the past few days I made my first batch and it did not seem to be short at all wedging it, the only difference I could see was visually maybe not as white. I did use it for a ton of handles and, so far at least, seems ok.
To be honest, if I could get away with just using it for attachments and random things that would be a win in my book. Regardless, I will test throwing it at some point just to see if it does need anything added as you suggested Min. 

@Morgan I'm hardly the expert around here, but its my understanding that at some point you need to work some "new" clay into the old and let it age.  There's probably a bit more to it than that.  So far I have been able to handle my "reclaim" a few pounds at a time, like 10 to 12.  For larger amounts, and repeated reclaim, things are probably different.
And no, you're not going to retain ALL the fines - even I don't and I'm the driest thrower I know.  That's why working some new clay in helps, as I understand it.  If things really get out of whack then you're adding ball clay or whatever is appropriate for the body you're working with, or epsom salts, or Veegum etc etc.  Stuff that's beyond me.

Certainly temperature has an effect. And I think that a small amount of clay will deflocculate faster than a larger amount would (as it needs fewer sodium ions to do so).
Flambe magic (John Britt's experience of crystal forming in glazes through thermal cycling)
http://ceramicstoday.glazy.org/articles/flambe_magic.html
Deflocculation
https://cawstudiopotters.wordpress.com/deflocculation/

It gets stirred every pot haha with a rush to dip, tongs in one hand and mixer in the other 
Thanks for the rework min. This is not meant to be a durable glaze it only goes on exteriors and for me, up until this fun little adventure/lesson, has been a pretty decent micro crystalline glaze that doesn't run and works well within my normal firing with natural cool. That said, I will certainly give that a test, thanks!

Awesome Dick and everyone else, that was what I suspected, so much appreciate the detailed response. I added an extra percent of Bent to 3% and my other variants of this same base glaze have not had this happen and they are much much older (some a year old no issues just 3% bent), this is a newer addition with simply a touch of copper carb to it. Anywho, I will add epsom salts as needed. 
Babs, it had been at least 2-3 weeks since I mixed the batch and the initial mix after sitting was totally fine. Glazed quite a few things, came back an hour later, and boom this happened. 

I'd be stirring your glaze every couple of pots if dipping, you'll find the copper at least, at the bottom of your bucket otherwise.
What Dick said 10x,  nephsy sets like a rock in that recipe, crusts in the inside of bucket. Why suddenly? Hmmm, because it could, murphy, showing who's boss, that's ceramics for you!

Better shorten your lubch break:-)

I'm not going to comment on the durability of this glaze but I did rework it to contain nearly double the epk and got rid of the nepsy and supplied what it did with a frit plus Minspar. Should suspend a lot better with less bentonite needed (if any at all). If you try it Morgan please just test a small amount first, what looks good on paper and all that.

edit: if you test this and find it's too fluid (because of the frit plus tiny bit of boron) then it might need an extra 1 or 2% of EPK

That's what I hope the experts will explain. I was just pointing out the use of a specific suspension agent for another glaze very high in  nepheline syenite.

How long since you mixed the batch?
Did you check the Spec gravity?
No expert here but if you haven't had hard panning with these ingredients you're lucky.
No expert, but I kmow that after a time the effort you've gone to to defloc or floc will need revisiting  because the chemical reaction needs a boost.
Heat will accelerate certain chemicsl reactions but not an expert just an observer.

Apologies, I should have included that but was on my phone. I do know that huge amounts of Neph Sy can change over time solubility, so maybe that is why, but still seems strange it has yet to happen to any other variants much "older" than the one that showed this behavior (and again, happened within an hour). This was a 4k batch all have 3% bentonite to prevent whats happening. I will probably add some epsom salt today (or more bent?) to try and fix it, but I am curious as to the why and why now more than anything.

As for the Hard Panning there was some water on top and the bottom had hardened to the point where a mixer would not budge in it, I had to loosen it up by hand and I finally got it back to normal. Update: Checked it this morning and it was already starting to happen again but not nearly the rate at which I saw yesterday. 

The strangest part of this to me is how it was 100% fine out of storage a few weeks and not until I starting using it did this kick off the issue almost immediatly.
This is the popular micro crystal recipe base "Frosty". 
Nepheline syenite 40.00  
silica 29.00  
zinc oxide 17.00  
whiting 9.50  
EPK 5.00
total base recipe 100.50 
bentonite 3.00 
rutile 2.00
 

Ya as min mentions the key is to pull the thicker clay after every collar which will prevent issues and maintain the integrity of the form.

Sorry, but yet another update that I hope helps anyone else that goes through the headaches I have gone through with this clay body.

So, all of the suggestions in this thread did help, the wedging, the compression direction (slow drying vs not) etc but I still found I was getting a 5-10% crack rate. Very minor, never through, but nonetheless present.

That said I have gotten this to 100% success rate adding a few more steps into my routine so I hope this helps.

First off, as many have mentioned, lets assume you have consistent thickness in your bottoms and forms, wedged well. From there two things seem to be the game changers for me. Instead of just compressing out > in, it seems the clay really loves to be forcefully spread in > out, then forcefully out > in. Take your time with this, I start my forms with a rather thick bottom and by the time I am done really compressing in both directions it is the right thickness. The last thing I do is when the pots are leather hard, if not a bit before, is use a tool of some sort, a spoon will work, a sponge stick, your finger, whatever....and compress manually outward in with said tool. With these two additions I have fired over 200 mugs with zero cracks.
When I say forcefully above I mean really forcefully. The way I came across this was by making some plates, which I laughed at while making, thinking of coarse a plate would crack. When I make plates I use a ton of force with my fist getting it wide, then compress in to even the surface…wouldn’t you know it, no cracks.

Hope this helps to those dealing with this in the future!

Sorry, but yet another update that I hope helps anyone else that goes through the headaches I have gone through with this clay body.

So, all of the suggestions in this thread did help, the wedging, the compression direction (slow drying vs not) etc but I still found I was getting a 5-10% crack rate. Very minor, never through, but nonetheless present.

That said I have gotten this to 100% success rate adding a few more steps into my routine so I hope this helps.

First off, as many have mentioned, lets assume you have consistent thickness in your bottoms and forms, wedged well. From there two things seem to be the game changers for me. Instead of just compressing out > in, it seems the clay really loves to be forcefully spread in > out, then forcefully out > in. Take your time with this, I start my forms with a rather thick bottom and by the time I am done really compressing in both directions it is the right thickness. The last thing I do is when the pots are leather hard, if not a bit before, is use a tool of some sort, a spoon will work, a sponge stick, your finger, whatever....and compress manually outward in with said tool. With these two additions I have fired over 200 mugs with zero cracks.
When I say forcefully above I mean really forcefully. The way I came across this was by making some plates, which I laughed at while making, thinking of coarse a plate would crack. When I make plates I use a ton of force with my fist getting it wide, then compress in to even the surface…wouldn’t you know it, no cracks.

Hope this helps to those dealing with this in the future!

Sorry, but yet another update that I hope helps anyone else that goes through the headaches I have gone through with this clay body.

So, all of the suggestions in this thread did help, the wedging, the compression direction (slow drying vs not) etc but I still found I was getting a 5-10% crack rate. Very minor, never through, but nonetheless present.

That said I have gotten this to 100% success rate adding a few more steps into my routine so I hope this helps.

First off, as many have mentioned, lets assume you have consistent thickness in your bottoms and forms, wedged well. From there two things seem to be the game changers for me. Instead of just compressing out > in, it seems the clay really loves to be forcefully spread in > out, then forcefully out > in. Take your time with this, I start my forms with a rather thick bottom and by the time I am done really compressing in both directions it is the right thickness. The last thing I do is when the pots are leather hard, if not a bit before, is use a tool of some sort, a spoon will work, a sponge stick, your finger, whatever....and compress manually outward in with said tool. With these two additions I have fired over 200 mugs with zero cracks.
When I say forcefully above I mean really forcefully. The way I came across this was by making some plates, which I laughed at while making, thinking of coarse a plate would crack. When I make plates I use a ton of force with my fist getting it wide, then compress in to even the surface…wouldn’t you know it, no cracks.

Hope this helps to those dealing with this in the future!

Sorry, but yet another update that I hope helps anyone else that goes through the headaches I have gone through with this clay body.

So, all of the suggestions in this thread did help, the wedging, the compression direction (slow drying vs not) etc but I still found I was getting a 5-10% crack rate. Very minor, never through, but nonetheless present.

That said I have gotten this to 100% success rate adding a few more steps into my routine so I hope this helps.

First off, as many have mentioned, lets assume you have consistent thickness in your bottoms and forms, wedged well. From there two things seem to be the game changers for me. Instead of just compressing out > in, it seems the clay really loves to be forcefully spread in > out, then forcefully out > in. Take your time with this, I start my forms with a rather thick bottom and by the time I am done really compressing in both directions it is the right thickness. The last thing I do is when the pots are leather hard, if not a bit before, is use a tool of some sort, a spoon will work, a sponge stick, your finger, whatever....and compress manually outward in with said tool. With these two additions I have fired over 200 mugs with zero cracks.
When I say forcefully above I mean really forcefully. The way I came across this was by making some plates, which I laughed at while making, thinking of coarse a plate would crack. When I make plates I use a ton of force with my fist getting it wide, then compress in to even the surface…wouldn’t you know it, no cracks.

Hope this helps to those dealing with this in the future!

grolleg will always be pricier than domestic clays-The shipping is killer

Its been a weather issue I'm told-from the big rains in the south affecting mining.. We are living in a less stable climate time and wet materials do not mine well
The tile 6 works fine in glazes

If you need it for glazes, just about any kaolin will work. I've used Sapphire, grolleg, Tile 6, etc, without problems.