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Maybe there's a hidden agenda from the school district.

The nearly 1/2 hour soak at the end of the firing plus what you said about your kiln reading cool is likely taking you over the 1250C mark. Get some cones in the kiln to measure what the heatwork actually is. When work is thin I've noticed it tends to bleb/bloat more if it's overfired than a thicker walled piece. It sounds like your glaze needs to be fired hotter than your clay.

Looks like a classic case of blebbing (bloating) from over firing the clay. Body is breaking down from being over fired and is off gassing into the walls of the pot. Were the pots all made from the same batch of slip? How big is your kiln, what's your firing schedule and were the ones that don't have the problem closer to the center of the kiln shelves? Do you have some cones to verify what the kiln is actually firing to? What does the clay manufacturer say the top temperature for the clay is?

I use this stuff from Spain. I think the peppers are smoked as they are being dried. More flavour than regular paprika. @Callie Beller Diesel, if you toss 1 or 2 ice cubes in the food processor just before it's done it makes the hummus creamier.

Lunch today, 4 days to sprout the seeds in a mason jar on the kitchen counter, (clover, alfalfa, radish & mustard), hummus and hard cooked egg on ww crackers. Corner of the bowl in the background is one of my dinner bowls. Hummus recipe is just by eyeball, chickpeas, lemon juice, olive oil, sesame oil (I’m out of tahini), garlic, salt, smoked paprika and an ice cube in the food processor.

It would be really helpful if the companies that make underglazes say what the base glaze should or shouldn't contain like Mason stains does. Spectrum lists 561,562,563, 567,568 and 569 as containing cadmium. I contacted Speedball a few years back and asked which of their underglazes contained cadmium and was told their orange, yellow orange, melon, red, burgundy, violet, pink and purple all do.

As well as the zinc issue the amount of calcium in the glaze can make a difference in how pinks/reds/purples turn out. If those underglazes use a chrome/tin stain then the covering glaze needs to be high in calcium or the colour will be washed out. If the pinks/reds/purples use a cadmium inclusion stain then the covering glaze isn't as fussy as to it's makeup.

It's a good idea to be there when the kiln is approaching the end of the firing, especially since this is a new kiln and controller. If you want to fire overnight then use the delay start function and time it so the end of the firing will be when you are up and around to check the kiln. Let us know how the pots turned out.

Try emailing it to yourself, should be able to reduce the size that way.

If the rim is uneven when you flip the pot over it won't sit level on the wheelhead and you'll get the issues you described. If you want the rim to be uneven then you need to trim the pot while it's supported on a chuck or chum. These are just humps or hourglass shaped cylinders to fit inside the pots upon which they rest on while you trim, usually made of clay, used unfired or bisque fired. Other solution would be to use a needle tool and trim the rim level when you are throwing it and have finished pulling the walls of the pot. Trim then smooth and round the edge. Welcome to the forum!

@Round Lake Pottery, I edited your title to better reflect the content on your post and moving it over to Studio Operations and Making Work. Welcome to the forum!

It's hard to see on your image but it looks like the blue figures running along the bottom of the graph are hours and the orange are the segments and the temperature rise is on the left vertical side of the graph. If this is correct then it looks like the firing took approx 9 hours. Is there a function on the controller to review your last schedule? Welcome to the forum. edit: is the "Time of firing" the actual time of day the kiln started or finished?

Bailey Mixer/pugger works really well for mixing clay. I throw everything but the kitchen sink in there, mix, add water, mix some more then pug. I like the way we are already trying to figure out which one would be best for Joseph

Puggers with screens, like the Bailey de-airing ones aren't going to work with the rocks Joseph adds to his clay.

How wet the clay is makes a difference in how it rolls out using bedsheets. I use both bedsheets and canvas, with the bedsheet I tug on the end of the sheet as I'm rolling the clay through, it helps avoid the wrinkling but isn't perfect. There is finer canvas than what the ceramic places sell, canvas duck cloth from fabric shops is available with tighter weave than the typical canvas used with slab rollers.