Hulk

Could be the cooling rate?
Faster cool, more gloss; slower cool, more matte.
The tiny kiln almost certainly cools down faster - more surface area to volume (and mass).
While waiting on more replies, please post the glaze recipe.

Forgot to post an update: It was most likely the two firings combined with a too thick glaze. I did the same combo again with thinner glaze and one firing and they came out fine!

Aye!
Best launch for paper airplanes since our third-floor apartment in Vercelli, Italy (oh dear, almost sixty years ago), where we were kitty corner to a large plaza/roundabout!
The warming air maybe provides some lift, and it's all downhill to the fairway...
...oh, well, we were a half block or so away.

When one's paper plane got out around the corner on a warm still day, it could make it all the way to school - the two story in the background there.
I'd had almost a year of school in England, then, when we returned to the States, "they" said I was too young for 1st grade, to kindergarten with 'ya; well, Mom was having none of that. I stayed home, then we moved to Bella Italia, where I entered 1st grade mid-term.
A bit off topic, but a balcony is involved.

My partner has (and is) supportive of my activities, and vice versa.
She knew there'd be a gap to fill once retirement became a reality; maybe family, friends, reading, home projects, biking, hiking, fishing, swimming, and volunteering wouldn't be enough.
This topic surely got me thinking about all the interests and activities my partner has supported over the years...
Any road, specifically, she allows time and space for my exploration in ceramics, expresses a more than reasonable amount of interest, and leverages the supply of (potential) gifts for family and friends. She uses wares daily and resists my attempts to clear out "bad" ware to the point that I'm much more selective now when culling what cannot be given away (much less sold) to be maybe kept for our own use, drilled to become a succulent planter, or broken. If to be drilled or broken, it has to happen now!
Thanks for sharing, hope there's more responses afore this thread slips down into the archives...

My partner has (and is) supportive of my activities, and vice versa.
She knew there'd be a gap to fill once retirement became a reality; maybe family, friends, reading, home projects, biking, hiking, fishing, swimming, and volunteering wouldn't be enough.
This topic surely got me thinking about all the interests and activities my partner has supported over the years...
Any road, specifically, she allows time and space for my exploration in ceramics, expresses a more than reasonable amount of interest, and leverages the supply of (potential) gifts for family and friends. She uses wares daily and resists my attempts to clear out "bad" ware to the point that I'm much more selective now when culling what cannot be given away (much less sold) to be maybe kept for our own use, drilled to become a succulent planter, or broken. If to be drilled or broken, it has to happen now!
Thanks for sharing, hope there's more responses afore this thread slips down into the archives...

I’ve been humming and hawing over this question, was going to pass on making a comment out of respect to those amongst us who live a single life and might be having a difficult time reading these tales of love and understanding. 
I am one of the fortunate people who has a sympathetic and understanding life partner. The respect and considerate nature we have for each other and what we do with our chosen paths isn’t something that is limited to how we spend our days make a living. We started off with student debts and stretching out the pay checks to make ends meet then as time went by found ourselves with a mortgage and 4 daughters.  Just to make things more complicated I left my well paying job to make a go of selling pots.
Being supportive isn’t just restricted to a tolerance or a shallow understanding of the trials and tribulations of working at making a living with clay and all that it involves. Does it still require an understanding and at times boatloads of patience? Hell yes! Could I do this without an understanding partner? Yup, I’m sure I could but it would be more difficult. I have deep and profound respect for people who make a go of working a lifetime in clay, especially those who do it singlehandedly.

My husband has always been supportive of my clay life.  I started my small business after I had retired and he retired a year later.  He takes the clay downstairs for me, helps haul greenware out of the house to the shop where I fire,  has worked some of the larger out of town shows with me (he is a good wrapper of pots).  I have made pots working around a shoulder repair, a hip replacement with a fractured femur, and a knee replacement.  So my husband has been a great help with loading and unloading the kiln.  I had an unexpected kiln repair one November and had the kiln torn apart replacing elements etc,  it was -30 degrees and 10:30 p.m with a show looming.    I was at the end of my last nerve, he came out to check on me and lend a hand.  I said, "don't you wish I had became a knitter and sold hats?"   He said, "no, that wouldn't have been nearly as interesting!"  
r

My husband knew I was serious about clay when we met,  I was 17 he was 19.  When we married I was 21,  we bought our first house a couple of years  later and that is when I got my first kiln.  It was our first major purchase for the house,  other couples buy a refrigerator or a sofa we bought a kiln.  A year later I got a scholarship in art to Wichita State and quit working to go back to school.   He has always supported me but never liked my work,  he worked in engineering  department and my work wasn't precise and perfect enough for him.  I tried not to  let is bother me,  I had the best support otherwise.   He was always encouraging me to buy new kilns,  but I wasn't  ready to jump into the world of controllers.  Last fall  I finally jumped and bought a Paragon Caldera with a Genisis Controller,  easy to use so I ordered a LL kiln with a Genisis Controller this year.   Since my husband has retired he likes to go to the ceramic supplier with me,  he  moves my clay  and loves to unload the kiln.   Right now I am glazing a 3-D landscape mural,  some of the tiles warped or twisted,  he is at the tile saw cutting and checking them with me to see if they will work or need remade.   I only had to remake one tile among the 200 tiles of the mural.   I likewise support his passion of restoring cars,  my passion is less expensive than his but he can always sell a car if he needs the money.     Denice

I have no family anywhere near me & no "significant other". My daughter is on the opposite coast and is actively helpful with kicking ideas around and provides useful feedback re marketing/photography/types of items. She suggested I do the plant stakes--I hated making them but they sold like hot cakes when I needed some quick income.  My sister has worked in clay herself (totally different style/technique) and understands the craft,  which is much appreciated. I have one friend who has really gotten me through the highs & lows, from 2014 when I decided to make myself a studio, to the present when I am struggling with some limitations and trying to decide what  to do.  He has helped with logistics and sales, managed my inventory, done my spread sheets, taken reference pics, proof-read text, provided assistance with my web page, and given lots of "common man" perspective on items that I put out for public consumption. I have another friend who has sat with me at the few craft fairs/shows I've done, including all that packing/hauling/unpacking/rehauling.  He also did a lot of the chatting with people coming to see what's what and managed to sell more of my stuff than I did! As a group, they have become essential to supporting my "need to create", through thick & thin. 

I have tried to keep my wife out of my line of work but that said she still has done my local shows with me. I have another assistant that helps set up and down but she has helped sell. Also we have set up my Christmas s booth and knocked it down on xmas eve for many many decades (now retired for that) I only have one local show now and she will help sell-the two days . She can play in studio all she wants but I do all the studio work myself or with my assistant-priceing packing. She will ocassionall drop an order off locally. Right now she has a herniated disk so all thats ioff the table and I am doing all the heavy lifting. The garden I rototill and plant and until she heals I'm doing the whole bit. She had her own carreer (now retired ) so I have done my best to keep clay my own career . She used to do a few traveling shows but its been a decade or more on those as well now that she had done. She did do 2 my last NV show two years ago ona road trip that we saw my Nephews one year old twins. But it was the twins not the show that she came.

That depends...This time of the year, getting into the studio is difficult. Since Spring has sprung and everything is growing on our1.5 acre property with multiple lawns and a lot of trees, landscape maintenance is a given and I am the one who does most of that. Then there is also the farm. While the fruit trees and vegetable patch occupy about 1/4 acre, the rest of the 3/4 acre is open field, and with the abundance of rain we've had this winter and spring, it seems like keeping the wild grasses down is a forever task. So, with all that going on, if I say I'm going into the studio, I get a look that says "Seriously...with all the yardwork that has to be done?" However, regardless of "the look", I go anyway just to get the feel of the clay in my hands instead of the dirt from pulling weeds. Then there are the times when, going through a magazine, she comes across something that she likes made by another artist and excitedly suggests that I might make something similar. So, I would say she runs hot or cold...

Hi folks, running a little behind here with the QotW. However, I have been thinking a lot lately of my wife, and her participation and support over the years when dealing with clay. She puts up with a lot, from the tracking in of clay dust from the garage to the time spent alone because I am busy playing with the clay. She has even put in time during the show years helping me pack, price, set up, and take down. She has sat booths with me, and without me when I was busy getting more pots out of the kiln for the days show. She did most of the base glazing in the early years, sometimes with help form a girlfriend. Then I would put on the decoration and finishing touches. When my kiln burned out a few years ago, she was the one that told me to buy a new one and don't take too long. . . saying she would find the money. She knows that I have an itch called ceramics and that it makes me a better person when I can do it. Makes me wonder. . . . how does it work for others out there?
QotW: How does your wife, husband (or significant other) and other family deal with your need to create ceramics?
best,
Pres

The kiln should be vented for both fumes and heat. That could mean an overhead hood, a ceiling vent that's sized for the kiln and room size, or either of those in combination with a downdraft vent.

Thank you for your input.  What you said  makes perfect sense since there was a days' delay before I applied the sencond glaze. This has not been the case when the glazes were applied  with a short delay between applications and they worked beautifully..  I will try again without the dely.

Hi Erin,
Welcome to the Forum!
Mighty Mud Mixer (Knoxville, TN) might be able to help you.
They have several commercial glaze lines, recipes they mix, and  they do custom orders which they can ship dry.

Hi Erin,
Welcome to the Forum!
Mighty Mud Mixer (Knoxville, TN) might be able to help you.
They have several commercial glaze lines, recipes they mix, and  they do custom orders which they can ship dry.

Hi Erin,
Welcome to the Forum!
Mighty Mud Mixer (Knoxville, TN) might be able to help you.
They have several commercial glaze lines, recipes they mix, and  they do custom orders which they can ship dry.

Seconding Min's point(s) on clays - for functional ware, firing to vitrification* is a worthy goal.
Hence, the heat work required to vitrify the clay drives the firing schedule, imo.
However, I'd guess that it's certainly possible to find a clay that behaves well when fired to 1250 C; also, some clays can tolerate a bit of over firing better than others...
Looks like Bath Potters offers a lot of clays!
They have a page that provides details on all their clays, including vitrification range, et cetera...
Still, I'd rather pick the clay or clays I want to work with, then adjust the firing, over the other way around (choosing clays to fit my firing schedule).
For food contact (the inside part), glossy glaze is easier to clean.
A glossy glaze doesn't hide defects (e.g. crazing, fizzy bubbles, etc.) like a matte glaze does, and can be very durable, also mark resistant.
...back from a nice long early Summer** bike ride.
While out there, was recalling where I'd looked for recipes, when starting out (just over five years ago).
This Forum
digitalfire.com (navigate to recipes from link, below)
John Hesselberth's FrogpondPottery.com***
Susan Peterson's book The Craft and Art of Clay
Lakeside Pottery's website includes some glaze recipes****
Another book I'm not remembering just now, will look for it ...not finding it, will try again later
Bill van Gilder's book (I use two or three from his book) Wheel-Thrown Pottery
I was looking for recipes from a known source, where there are usage and/or testing notes included (pictures are nice too)
A well behaved clear liner (there's enough white in mine to show over dark clays) glaze took some time, testing, trial, start-overs, some help, and then aaah. 
It has significant MgO, small amounts of Sodium and Potassium, a dose of Lithium (a little bit makes a difference!), and there's Boron - it melts well - for I work cone 5/6; there's enough Silica and Alumina to make a tough glaze that doesn't run or sag much.
*Vitrification (digitalfire.com)
**It's warm enough, I'm calling it Summer!
***archived here Tested Glazes | Frog Pond Pottery (archive.org)
****Cone 6 Glaze Recipes | Great Mid Range Pottery Glazes (lakesidepottery.com)

Seconding Min's point(s) on clays - for functional ware, firing to vitrification* is a worthy goal.
Hence, the heat work required to vitrify the clay drives the firing schedule, imo.
However, I'd guess that it's certainly possible to find a clay that behaves well when fired to 1250 C; also, some clays can tolerate a bit of over firing better than others...
Looks like Bath Potters offers a lot of clays!
They have a page that provides details on all their clays, including vitrification range, et cetera...
Still, I'd rather pick the clay or clays I want to work with, then adjust the firing, over the other way around (choosing clays to fit my firing schedule).
For food contact (the inside part), glossy glaze is easier to clean.
A glossy glaze doesn't hide defects (e.g. crazing, fizzy bubbles, etc.) like a matte glaze does, and can be very durable, also mark resistant.
...back from a nice long early Summer** bike ride.
While out there, was recalling where I'd looked for recipes, when starting out (just over five years ago).
This Forum
digitalfire.com (navigate to recipes from link, below)
John Hesselberth's FrogpondPottery.com***
Susan Peterson's book The Craft and Art of Clay
Lakeside Pottery's website includes some glaze recipes****
Another book I'm not remembering just now, will look for it ...not finding it, will try again later
Bill van Gilder's book (I use two or three from his book) Wheel-Thrown Pottery
I was looking for recipes from a known source, where there are usage and/or testing notes included (pictures are nice too)
A well behaved clear liner (there's enough white in mine to show over dark clays) glaze took some time, testing, trial, start-overs, some help, and then aaah. 
It has significant MgO, small amounts of Sodium and Potassium, a dose of Lithium (a little bit makes a difference!), and there's Boron - it melts well - for I work cone 5/6; there's enough Silica and Alumina to make a tough glaze that doesn't run or sag much.
*Vitrification (digitalfire.com)
**It's warm enough, I'm calling it Summer!
***archived here Tested Glazes | Frog Pond Pottery (archive.org)
****Cone 6 Glaze Recipes | Great Mid Range Pottery Glazes (lakesidepottery.com)

I’m not going to tell anyone their experience is invalid, but I am going to point to the response I made right above yours.  As you pointed out, there’s not a lot of info on mycotoxins in clay, but at a glance there’s a LOT of it regarding medications, grain storage and animal feed. 
Humans have worked with clay for centuries, and of all the health issues that are prevalent, assorted mould allergies or contact reactions do make the list. You can smell the petrichor when you open the bag, and see the spots. Clay that you buy from a supplier at some point was part of a river bank, and it doesn’t get washed or anything before the components get sieved and mixed, so it should be no surprise that things grow in it, whether its “fresh” or reclaimed. In fact it’s relatively common practice to encourage a certain amount of mould growth in clay for plasticity, and for otherwise healthy folks, it’s not an issue. Keyword there is healthy.
If you’re immunocompromised for any reason, the advice is first and foremost to discuss with your doctors and other healthcare providers. 
 

I would strongly recommend first sorting out which clay has an absorption of under 1.5% (one point five %) at your chosen temp and / or exploring the possibility of running a manually set program with your kiln. It's important to match the clays firing qualities with the kiln not the other way around. If you start a thread in the Equipment section here giving the name of the kiln and what your preset firing options are someone might be able to help with this.
In regards to your glaze recipem have a look at the recipes on Glazy and see how yours compares to ones there.  Put in your search parameters and then compare your recipe to some there while looking at the chemistry, not just the recipe itself. If you aren't sure what a material is or what it contributes to the glaze then click on it in the Glazy recipe and it will take you to a materials page that gives chemical info plus lists similar materials. There also was a recent post in  this thread for a Linda Bloomfield gloss glaze (she is an American who lives in the UK).  

I did another firing without changing anything and all pieces where fine. 
The kiln is a top loader and the  shelf  was near the bottom of the kiln. Going to have to get some more cones to test the temperatures. If it happens again I will try the soak! 
Thank you
 
 
 

Ahhhh! Thank you! When we did the offset we entered using the 9 not realizing that was a negative. The manual we were looking at didn’t explain it as clearly as these instructions you’ve provided and only showed the offset with the 9 (for example, 9020 for 20 degrees). I believe this is our problem! Our maintenance crew has all but given up. Thank you!!

One of my favourite tools is a stone I picked up at the river. I've sanded it smoother so it's got for burnishing, and shaped it so one edge is sharper and a little pointed while the other side is rounded. It fits comfortably in my hand and I use it for pinch pots, smoothing clay into joins, burnishing and plenty of other bits and pieces.