Hulk

Going through the clay charts at Standard Ceramics lately, and thinking back to all of the interesting thoughts and discussions I have heard over the years. Wife says: Oooh!  that's a pretty color why not that one? Hubby: stains everything, absorption is too high. . . glazes wont fit it.  Wife: Aww you could do it. Hubby, Not interested! Wife: Oh. So how do you decide on a clay body, is it price, or fired characteristics, or working characteristics, or even just because you always use it, or is it word from others passed along?
QotW: When buying clay bodies, what characteristics do you look for in the clay? Especially when buying a new body you have never used before.
best,
Pres

Thanks for the info.    Looks like I have some work to do.
The glaze is cracking, not the clay.  

I have several of these inexpensive plastic calipers*, handy in the Studio, a few dollars at your local hardware store or online.
If/when they break, bend, wear out - not a big loss!
Plenty accurate within a small fraction of a mm (depending on one's eyesight); the vernier is decent.
Typically, the depth bit on these cheapies don't line up with zero, but that's easily accounted for...
For larger wares, I'm using a fifteen inch Fiskars stainless steel ruler, graduated in mm and inches, which I find handy...

*when a more accurate measurement is required - within a thousandth or two (inches) - I'll break out a spendy caliper or micrometer.
I haven't yet needed to use any expensive measuring equipment when working with clay. The one exception was testing to see how small a vertical wheel head wobble is perceptible - a few thousandths is enough to be annoying, yep.
In my ceramic practice, within a fraction of a millimeter is almost always "close enough" - and for ordinary projects as well, e.g. bolt/screw/drill size, blind hole depth, et cetera, a cheap plastic caliper is practical, useful, and low ri$k...

Thanks guys, much appreciated. Hulk, I've been thinking along the same lines, keeping moist spots might keep the hermit crabs happy they do like to dig. 
Graybeard 

Detailed notes might be helpful, as new accidents may occur (likely), and some o' them happy as well!
I wanted to suggest using cookies, just in case, aka waster slab, a thin slab of clay the glazed ware sits on, which will prevent running glaze from pooling up on the the kiln shelving.

Detailed notes might be helpful, as new accidents may occur (likely), and some o' them happy as well!
I wanted to suggest using cookies, just in case, aka waster slab, a thin slab of clay the glazed ware sits on, which will prevent running glaze from pooling up on the the kiln shelving.

That glaze does not have any Gerstley Borate. There is no way it would look like that unless you under-fired it. The fact that you can put another glaze on top of it and it is still mostly on the test tile means there is definitely no GB, unless that other glaze on top has absolutely no frit in it?
So if you wanted to replicate that glaze and figure out what it is, I would do this.
1. Since you said you had a few unlabeled bags, I would mix up that exact glaze but missing the 50% GB.
2. Figure out how many cups you want to use, so say its 10 attempts to figure this out. Measure out 100ml of glaze with the mystery recipe but don't include the Gerstley Borate. Instead leave that out. But use the same amount of water you would have used if it was in there.
3. Measure out 10ml with a syringe into each cup, making sure you stir well before each one. I use a milk frother for this...
4. Take your 10 mystery attempt materials that look similar to Gerstley Borate that you might have used instead. Put 50% weight(the missing GB amount) of the mystery chances into each cup. You will have to do the math on this to figure out what this should be, but it isn't difficult at all.
5. Glaze a test tile or a little test dish or whatever you want in the 10 mystery glazes and make sure to record everything.
6. Fire it all on the exact same schedule with the same load mass that you did for the first tile.
7. Pull out the results and keep any of them that look similar to the original tile, go from there.

As a Moderator, I am letting the Forum community know that there is an App out there for doing much of the organizational work for arranging classes, firing the kiln and measuring what is fired. Just do a google search and it may be yours at a price. Listing such is against the Terms of Use for the forum. Thank  you for your patience.
 
best,
Pres

depends on the tightness of the clay body(what cone 6 clay  body)-the absorbion rate? Usually clay needs a glaze unless it really a tight body.

Lately I have been using the stencils, stamps and branches etc directly on the slab after rolling, actually embedding into the slab a design. In the slab piece here, I used a large slab, decorated completely then cut to slabs for use so the design went around the piece. After bisque, cobalt and iron stains were used under the glaze,  
Glazing was completed using dipping, pouring and atomizing layers of opaque, and transparent glazes to build up the surface.
best,
Pres

Hi colormek8art,
Welcome to the Forum!
Wow, that kiln looks to be in good shape.
While waiting on responses, could you confirm the phase requirement; is it three phase?
Also curious, what are the amperage and max temp ratings?
To test/run safely, the wiring must be proper.
The max temp rating could be important; what temperature target/range do you work in?

Most glazes I’ve used benefit from slaking overnight before sieving. Given Tony says that Tile 6 “is relatively impermeable to water compared to other kaolins, it is thus the last choice for casting bodies,” I’m curious what the comparison is between the glazes a week later.  
Side by side, there seems to be a few more impurities in EPK than Tile 6. While the flux comparisons have some variation that might need watching in a glaze formula, the silica and alumina balances are close enough that part might not matter. 
Tile 6  is known for its plasticity in clay bodies, which I can confirm from personal use. The plasticity may have an effect on some high clay glazes where shrinkage could affect application, but that’s theory on my part, and if someone knows better, speak up. 
As to why a material might be washed and another isn’t: we have to remember that potters are a secondary market for almost all of the materials we use. EPK I think gets used to make glossy magazine paper. If tile 6 is mined for something else, the washing may not be necessary. 
Edited to add:
Links to Digitalfire materials pages for comparison. 
Tile 6 writeup
EPK writeup

State of Louisiana, City of Los Angeles, or?
There's Louisiana Mud Mavens Ceramic Art – Louisiana State Exhibit Museum (laexhibitmuseum.org)
and Current and Upcoming Exhibitions (nolaclay.org)
The drive through daquiri in Lafayette used to have "two-for" Tuesday (on Tuesdays) ...crawfish season is mostly over, but there are many other wonderful regional eats!

please check out www.amoca.org. - American Museum of Ceramic Art in Pomona, which is a stone's throw from Los Angeles. They have an event page that shows a couple of items during your stay. The museum in and of itself is well worth a visit. 

Good question!
I'd be tempted to widen the definition of "tools" to include track shelving* and a rolling cart.
Then a few more buckets.
The Studio needs (aah, I need!) the wall put up and mini-split installed; so, so hot!
I'm good for tools right now, looking forward to setting up and firing the new kiln when it arrives!
There's some open space in the Studio now, but still lots of organizing, demo and remodeling to do.
I'm getting lots of miles out of relatively inexpensive (it's $26 on ah maze on right now) US Balance "US-Benchtop-Pro" scale; it performs consistently and well.
Its max is 2000 grams, hence, for larger glaze batches, there are more steps.
If choosing again, I might go with the 3000 or 5000g models, maybe; the 3000g model can be had for less than $40 ...
 
*I like the metal tracks that screw to the wall; shelf support brackets snap into the track.
Higher up and on the end there, for glazes, glaze materials and some other stuff that's nice to have handy but aren't used every day; at "wheelhouse" level, green and bisque ware queue-up space.

Good question!
I'd be tempted to widen the definition of "tools" to include track shelving* and a rolling cart.
Then a few more buckets.
The Studio needs (aah, I need!) the wall put up and mini-split installed; so, so hot!
I'm good for tools right now, looking forward to setting up and firing the new kiln when it arrives!
There's some open space in the Studio now, but still lots of organizing, demo and remodeling to do.
I'm getting lots of miles out of relatively inexpensive (it's $26 on ah maze on right now) US Balance "US-Benchtop-Pro" scale; it performs consistently and well.
Its max is 2000 grams, hence, for larger glaze batches, there are more steps.
If choosing again, I might go with the 3000 or 5000g models, maybe; the 3000g model can be had for less than $40 ...
 
*I like the metal tracks that screw to the wall; shelf support brackets snap into the track.
Higher up and on the end there, for glazes, glaze materials and some other stuff that's nice to have handy but aren't used every day; at "wheelhouse" level, green and bisque ware queue-up space.

Looks like Cobalt Carbonate price has dropped recently!
Petalite price hasn't...

I have some old china dolls and a few newer black clay pieces. I’ve always cleaned them with mild soap and water. I imagine that large, pale Parian surfaces which are not cleaned often might acquire some stains that could be hard to remove, but the relative non-absorbency should prevent most permanent staining. There are removers for rust stains that should work on Parian (test first on inconspicuous spot) and other types of dedicated cleaners for other stains. Vinegar and water would be my first attempt. Hydrogen Peroxide solution also, for mild bleaching without damage. 
The beautiful Wedgewood dinnerware is made of Parian, with no additional glaze. I wouldn’t leave my blueberry cobbler sitting on it overnight, though. 

Tough question!
Parian* is generally defined as a "self-glazing porcelain" which appears to have nearly zero absorption.
How are you using Parian?
Do your finished wares absorb water, at all?
 
*Composing a Workable Parian Clay Body (ceramicartsnetwork.org)

Tough question!
Parian* is generally defined as a "self-glazing porcelain" which appears to have nearly zero absorption.
How are you using Parian?
Do your finished wares absorb water, at all?
 
*Composing a Workable Parian Clay Body (ceramicartsnetwork.org)

When I google PA clay manufacturers, Standard comes up as one of the first ones, and several forum members here use that brand. Hopefully one of them chimes in. They have a big ‘ol list of cone 6 clays here, with about 7 options that have 1.5% porosity or less* and are some shade of white. They also appear to sell some kinds by the dry bag, which would be very useful for making coloured clay with, if you want more than just a yogurt container full for decorating. On the Standard distributor page, there’s a place called R.I.CH  Inc in Bernville and The Ceramic Shop in Norristown that seem to be the closest to Easton.
If accessing cone 10 firings is an issue, and it can be for some, there are options. If you have easy access to a gas kiln, never mind the above and carry on. 
Amaco is great for bottled glazes and underglazes, but their clay selections seem to be geared towards teaching scenarios where final porosity isn’t a primary concern. It also seems to run a few dollars more than some of the ones from other suppliers.
*whichever clay body you go with, you should do a porosity test under your own firing conditions to verify claims made by any manufacturer. You may be doing something different than they did for their tests. 

Looks like Cobalt Carbonate price has dropped recently!
Petalite price hasn't...

LED lighting might be worth a look - long lasting bulbs, high efficiency wins back the initial cost, and then more from there.
We used LED fluorescent tube look-alike replacements at the last house, particularly in the garage and Studio.
The round ones ("canless" recessed) that go into the ceiling are very reasonable now; we used them in our Son's bathroom remodels last summer. The light "temperature" is even adjustable! 
Our new house has them in the garage.
On the Studio side, I plan to chain in several more.

Example of cobalt concentration vs depth of colour
Cone 6 Ultramarine Cobalt Blue Glaze (Glossy Clear plus Cobalt Carbonate)
https://www.thestudiomanager.com/posts/cone-6-ultramarine-cobalt-blue-glaze-glossy-clear-plus-cobalt-carbonate

Tst
... but it doesn't have the cyan-ish tinge.

Thanks Peter - the 1% cobalt is close. Agree with you that a little more green needs to be added to get a blue closer to cyan. A good starting place though. May throw the question over to Glazy. Perhaps an Italian potter knows the formulation. I have Londi's bio, which I haven't read yet - may provide a few clues. Will report back if I nail it.