Hulk

Ok I showed up at noon and others where walking thru house buying up stuff. Looks like a small amount of my work had sold . . But the tables where still stuffed.I told the fellow for me its all or nothing deal. I made a quik  rough list and  and down sized my offer to 450 $ cash. I said I have the boxes and paper and will take only my work as there was other ceramics mixed in especailly on the floor under tables (not in the photos)He took the offer which is about 16 mugs for me sales wise these days. I boxed it into 6 Banana boxes  full and dollyed it out feeling great. The womans sister spoke to me and said the lady (her sister) had a stroke and was in full time care now in North Caralina.I said she had the most work of any customer I ever knew  of and gave her my card to thank the sister . I have never met here as 99% of all the work was from a few outlets and they all had the price labels and cards inside of them. Not my own show price labels but those of my Eureka outlets. The largest amout of stuff was from a co-op organic market I pulled out of a year ago as I am slowing it down with a plan. I put a care and feeding tag in every pot  then and all those where still in every pot. Now I have a nearly a 35 cubic feet whole  kiln worth of new old stock. Its insane really. In my 50 years I never in my dreams would expect this to happen. I'm selling the stock twice this time without having to make or glaze or fire it.  Of couse prices have risen since I sold this  originally so I'm really ahead . I'm making 4 dinner plates for the friend who sent me the info last night. She really came thru for me.
There where two tables of pots  like the one photo  as well as a bunch on the floor
Just when you think you have seen or heard it all   -boom something new surfaces .

Regarding lead:
"They haven't found a threshold level below which there is no harm."
"Current research hasn’t been able to determine a threshold for many of lead’s effects. That is, scientists haven’t yet found a concentration of lead below which no effect occurs."
I'm curious, is firing done in the same shop?
If so, where does the kiln vent, and what procedure/protocol for handling kiln furniture, and et cetera...

So last night I got a message on facebook from a fellow Board member (art show board)
Seems a hoarder with money passed away and their is an estate sale this weekend. The photos show a few huge tables of packed to the gills with my work as well as a large floor area . The Estate guy was posting lots of photos of tons of collected stuff  as this women had  passed away and collected huge volumes of work . I called him an hour after the post went up to ask whats the deal. He said he was in a huge time crunch to emepty the house . He was not autioning it but hoping to sell it piece by piece ,nothing is priced. I let him know i made all that pottery . Looks to be about 8-12 boxes full. I said if the price was right I'll take it all. He siad any reasonable offer he would take. Now In all my ceramics life I =have never bought my work back from anyone. The pots look all new and not used as there was too much volume to use -she was collecting not using. He said since you are the maker how about coming a day early and see what you want so today at noon I'm going. My plan is buy it for about 25%of retail tops. . Then just put it into my inventory . I have a pile of cash to sweeten the deal. Tbis may all go south today just as easy so its far from a done deal but its one heck of a strange deal. The forms are glasses ,mugs and bowls of all sizes from stacks of large serving to cereal bowls. I can see few pots that are not mine (not interested in) in the mix as well. I'll post the outcome.
This is the most work of any one single customer by far and it looks like it was mostly bought at my gallery outlets.I can tell by the colors (some now discontinued) and color combos of when the work was made. I had no idea anyone custiomer pould ever own this much stuff from me. I'm hoping I may have known her as well. we shall see today-its a strange world out there.

Document and get a lawyer. Get samples if you can. Being asked to spray a lead glaze with no PPE is in no way shape or form safe.  This employer has NO excuse. 

Is this toxic workplace making functional pots?
60% lead Bisilicate??? Your making a low fired clear glaze for hopefully non functional ware?
Get out of there. Read up on lead posioning.
Guess employer not providing sjowering facilities or total protective covering.
The occupants of the lead town are called leadheads by the ignnorant. Their brain functions affected to extent the children score WAY below the norm in all aspects of the educational testing. One example only of how lead affects the body. This is from exposure in the wide open. You are in a confined area. Dont tell me you are mixing the powders in a non protected area. Whole place washed down every night..
Laundering at home? You are pousoningbyour family 
 

Lead bisilicate is a fritted form of lead, this means it's less soluble (until fired) than raw lead. It definitely shouldn't be inhaled. Copper oxide will make a green glaze. There are National standards for the allowable amounts of leaching of lead. We don't know if the ceramics from the place you work are leaching, samples would need to be tested to ascertain the amount of leaching.
Immediate issue is for employees working there with the type of working conditions you have described. This isn't safe practice.
Second issue is the potential quality of the glazes after firing, this we don't know.
Third issue is the ethics of using a lead glaze under any circumstance. 
If there is any chance you are pregnant there is an added urgency to not expose yourself to this workplace.

Electric at .5 £/kwh is about $0.61 (US dollars), wow.
In Central California, off-peak Winter is just over $0.28/kwh (was 34¢ in Summer).
HBP, do the graphs depict percent absorption (water) by weight (vertical) for each trial (horizontal)?
If so, that's some good results!
I went with petalite (to lower liner glaze COE), cheaper per unit lithium (and avoiding the reported Spodumene foaming). Am seeing some small grey specks, but I don't mind them.


 

Have some interesting results from my Calcium, Magnesium and Lithium experiments. Might have to swap the Spodumene for Petalite as it is cheaper but I had both lying around and went for Spodumene.
These tests took about 80 hours to dry Starting mix is 20g dry ingredients and 13-15g water. Need to run more tests adding other clays and feldspars to reduce drying time.
 
There seems to be a Calcium and Magnesium sweet spot where too little or too much makes it more porous. The Lithium just seems to reduce porosity.
 
All tests with 5% frit but I have tried to annotate the graphs and reorganise tests as my numberings went a bit all over the place as I came up with ideas. I ran a pure ball clay sample and added the 5% and 10% frit  data from last time to the left of the chart for comparison.
 
These didn't actually make it to cone 03 and much more like cone 04. Cone 03 made it to about the 2-3 o'clock position so need an extra 10 min hold on the next firing.

 
Another graph of some 5% Spodumene 5% Frit + extras

Hi and welcome to the forum!
There was a discussion about this a couple years ago that was asking the same question. Might find it helpful.
 

The factor of porosity would be key. If the sculpture absorbs moisture , freezes, water expands, you will get a cracking and shearing off.
So firing to vitrification would be the way to go.
The properties of the clay body which allows you to construct your sculpture best would have to be considered.
I think I read of clay additives which when dried allow the forming of minute cracks around each piece whilst being great to increase tolerance of thermal shock may lead to cracking in instances such as yours.
@glazenerd may be of help

Looks like Keith is still in business; there's a phone number here:
Furnace Kiln Repairs | Keith Company
Comparing readings might be helpful, given you have access to a portable pyrometer, else compare your new pyrometer reading to a cone pack?

There's more separation at higher temperatures...
The wire colors appear to be a good first step.

Looks like Keith is still in business; there's a phone number here:
Furnace Kiln Repairs | Keith Company
Comparing readings might be helpful, given you have access to a portable pyrometer, else compare your new pyrometer reading to a cone pack?

There's more separation at higher temperatures...
The wire colors appear to be a good first step.

Looks like Keith is still in business; there's a phone number here:
Furnace Kiln Repairs | Keith Company
Comparing readings might be helpful, given you have access to a portable pyrometer, else compare your new pyrometer reading to a cone pack?

There's more separation at higher temperatures...
The wire colors appear to be a good first step.

we have some kiln experts here but they would like to see photos of the kiln and thermocouples and anything else that might be printed on the label.   i have never heard of that brand name and wonder if anyone else has.   the more info you give, the better the answer.

Did you buy one, or use one that was in the studio? Any packaging that indicates what type is is? Post a pic of it, and the old one if you still have it.
What model is the controller on the kiln? Kiln companies don't typically make their own, so you may be able to find a manual for it that shows a setting for thermocouple type.

Any relevance, or are there too many non-standard cables about?

Thermocouple Cable Colour Chart
https://www.pyrosales.com.au/blog/thermocouple-information/thermocouple-cable-colour-chart/
...and
https://www.hgsind.com/videos/how-identify-thermocouple-wire-color
In this video we’ll be focusing on the ANSI wire color coding used by the United States and Canada.
 

This may help along with Peters chart. You are likely checking between 3 types: K, Type R, and Type S so if those colors are present on the old thermocouple it would be great to note. A picture of the back inside of the control board likely reveals a jumper setting or terminal marking could give a clue. Pictures here likely very helpful
 

Did you do a Google search on the kiln? It looks like it was manufactured by Ceramic Fiber Fabrication (CFF) which became Keithcompany.com.
It looks like they are an industrial kiln manufacturer out of California. (BIG kilns in other words.) Interesting website.  They might have some information?

Thank you everyone for your responses. I was referring to the l&l vent-sure downdraft system. Just to be safe I will hang it slightly down from the ceiling so it isn't touching anything, but good to hear it doesn't get too hot in people's experience.  I appreciate the recommendation for rigid pipe, and I am planning to have a window open with a small fan going. Thanks! 

Hi Stuart,
The only tin oxide I've used is from US Pigment - seems to work ok.
I needed it for tin/chrome red (same recipe as Britt's "Chrome Red").
It's red!

I get the whole range too, from “what is this made out of?” to “what cone and atmosphere?” I think my favorite customers are not necessarily the technically knowledgable, but the ones who care a great deal about home design and function, i.e. making their home into a space where they feel happy. 
Over the years, I have found that as I moved up into a higher tier of craft shows, I really don’t meet the clueless ones anymore. And the ones who don’t know much about ceramics are at least smart people in general and know how to ask intelligent questions. 
I also like to talk shop with other potters. They aren’t necessarily interested in buying, they want to learn. That’s fun for me too. 

I've told the story before about the guy carrying a bucket of water to the Penn State festival because he wanted to buy good teapots and used the water to test them.
Then there are those that want to be certain they are buying stoneware, but don't know anything about what that means. All stoneware is brown, all porcelain is white, and low fire earthenware is red!
I have also had the casserole passed up, because the last one they bought cracked all apart in the oven. Fix it the night before, and put it in the fridge then take it out and put it into a hot oven!
Needless to say the lack of education for the public consuming functional ceramic is apparent, but there are bright spots as the day I sold 3 teapots to one customer!
 
best,
Pres

Its a huge mix from knowing a lot to clueless-like putting a teapot on open flame ( and breaking it the day he bought it) to heating bake ware up with oven and lasting decades. 
The public is  a petri dish of good bad and the down right clueless
As I slow it down  with the public I will never miss the clueless ones.Only the ones who are aware .

Hi folks, once again, no new topics in the pool for the question of the week. I will try one from a different angle. .. thinking about customers here! Over the years I have had several people that wanted to know more about pottery, others that just bought on impulse, and some the really knew about what they were getting when buying a pot of mine. I have wondered in the past where they got or missed exposure to pottery.
When I was teaching HS, I believed that part of my job as a teacher was to get my students to realize that even though they might ever make a piece of art they should understand what good pieces of art or craft would entail. Often this would entail talking about aesthetics as another story, but more often in was about the craftsmanship. When talking about pottery as a consumer I reinforced the things that I taught about making a pot: smooth edges, tight joins, well designed functional ware, glaze technique, weight balance, and other things. I always would tell students during introductory talks that even though the may not make pots again, they might be consumers.
QotW: How savvy are your customers about pottery?
best,
Pres

It’s an excellent point and possible under very special conditions and temperature rise (UL sets this as possible). But again if it’s a vent-a-kiln as the op specified, the duct will be near room temperature air. If it’s a downdraft that @Hulk mentioned then properly adjusted it will supply 100-130 degree air as the minor amount of kiln air must be diluted with room air in the mixing manifold at the kiln. Standard suspended single wall ductwork generally applies. Double wall and special clearance requirements generally apply to ductwork venting gas fired appliances.
Ensuring this is operating as the manufacture specifies is probably most important to get right and following the manufactures suggested venting requirements when extending.