Mark C.

Diving,.taking underwater photos,tuna fishing,building, electrical work, solar ,Topside photos, gardening ,Nature,Outback camping. Travel . Lifes short

I would check the burners and clean the orfices first as Neil suggests.
The kiln fiber board is cracked but not yet in bad shape.Except those massive opening arount the edges-you need to stuff thise with high temp fiber (loose stuffing) . At max temperature of 1300C  for that kiln means the interior layer needs to be well above that to keep from cracking and coming apart. My guess is you have lost lots of heat thru thosew ceiling spaces around edges which also will cook the button wires holding this together very fast now, The idea is keep the button wires cool and away from hot face heat. 
The lid has shrunk and the edges now have space exposed and you need to fix before firing again. That shows well in your photo of kiln ceiling.
That kiln is made of fiber board and I'm not a fan as it shrinks and cracks more than loose fiber unless its the very high temp stuff.
I would use material that rated to 1426C for all hot faces. For me thats 2,600 Fahrenheit. Fiber or soft Bricks As one who fires to cone 11 a lot it pays off in the long run.No spalling or excessive shrinking.

1260 in my world 2300 degrees  which is just at the temp you are firing to so 1st its going to shrink and crack
You need higher temp materials for cone firing in kilns for repeated firings. I would use 2600 degree fiber (you can convert as I had to to see what this temp is )
Fiber board and fiber rolls shrink and they shrink the most at maximum limits and thats where you are right at cone 10.
Even bricks at their limit will spall over time-say like acone 10 brick kiln with K2300 soft bricks they spall after reapeated firings. I have laerned this about 40 years ago in my kiln building life.
Repalce all the 1260c with higher limit materials-they will cost more.
The metal in that photo (photo needs to show a larger area so one can see what it is (a chimmney stack or kiln lid? )It looks like part of kiln frame and if thats true you need it.
I would need to see the inside of kiln ceiling and outside better to advise on the that metal bar and whats it doing. better and more photos
If you have used up the 1st tank and its low pressure less gas ,well yes it can affect reduction very much
25mm is what we call 1  inch and you need in my mind a minimum  of  6 inchs or 16 centimeters for a kiln ceiling of fiber for cone 10 firings. More would be better
You only need the hot face to be 2600 degree material-say the 1st 2 inchs thgen the cheaper 1260 material can be the rest of the make up to get -9 inchs of ceiling in total you need
My guess is you are losing the heat through kiln ceiling.Lots of heat
Fiber board for me shrinks  and cracks more and I prefer fiber blanket with buttons to hold it up but this will fail over time.. It's not the best for ceilings because of this.. You can fold it in U shapes and compress it with stainless rods and steel ends and it works well for flat ceilings this way.
I have a salt kiln made this way with a 9 inch thick ceiling and the rods are about 6 inchs up from hot face. I folded  the  2 foot wide blanket  in half and cut it to make the 9 inch folded tacos(this takes about 22 iches of 2 inch thick fiber as tghe fold trakes up length  and compressed them in a wood form and rammed a sharpened treaded stainless rod (use nuts on ends ) through them with a flat bar on each end to compress the tacos into a tight flat roof that is a uni solid one piece unit that sides on kiln walls.

I would check the burners and clean the orfices first as Neil suggests.
The kiln fiber board is cracked but not yet in bad shape.Except those massive opening arount the edges-you need to stuff thise with high temp fiber (loose stuffing) . At max temperature of 1300C  for that kiln means the interior layer needs to be well above that to keep from cracking and coming apart. My guess is you have lost lots of heat thru thosew ceiling spaces around edges which also will cook the button wires holding this together very fast now, The idea is keep the button wires cool and away from hot face heat. 
The lid has shrunk and the edges now have space exposed and you need to fix before firing again. That shows well in your photo of kiln ceiling.
That kiln is made of fiber board and I'm not a fan as it shrinks and cracks more than loose fiber unless its the very high temp stuff.
I would use material that rated to 1426C for all hot faces. For me thats 2,600 Fahrenheit. Fiber or soft Bricks As one who fires to cone 11 a lot it pays off in the long run.No spalling or excessive shrinking.

lusters work best on glossy fired surfaces so after the pit fire on top of a shiny glaze is what they are designed for.

Continuing to experiment with the first technique of sucking the clay back in and it seems to be helping, thanks! 

So as far as a new Oring as thats what the door is sealed with. Look for a nick.A nick in the ring can ruin the seal. I suggest taking out the ring and cleaning the grove and ring and putting some silicone grease (only a little bit) on the oring and reinstalling and try that as youi can inspect teh ring well at that time its out. Do not use any sharp object on it. Only use plastic tools on it to  claen scrap clay away. I run a rubber rib around my Orings  and try to keep clay away from the seal. Especially dry clay. This is true with the overflow door as well. That door also will leack if not kept claen. Sometime I have to push on my overfloow door while vacuum is on to get a seal. Have you tried that????

I use my VPM 20 and VMP30 like Jeff describes. I also put the first  log back in for next time about 1/2 the time if it funky .You can get the machine to such clay back into mixing chamber easy(put the cap back on when the clay goes past nozzel end into chamber. 
On a more curous note what are the vacuum tests that they mentioned ?

if its just been bisqued bisfix will work fine for this. See above video
There are other menders that work as well like Marks mender and highfire mender for glaze wares-I have used them all

SO I just fired my Geil 18 cubic foot kiln  and the 12 cubic uodraft yesterday with this year's 1st fires (2024) and looked up my slow down years total for 2023
I'm loving the new to me Geil-I replaced the honeywell conroller with a longer (gas 90 second pilot hold feature ) hold down feature which makes it easier to light
With the 20 new Bailey 14x28 monster  huge advancer like kiln shelves this kiln really holds more like 20 cubic feet now-I did sink about 15 k into the kiln and shelves and concrete slab job  and  and the 20 foot LVL beams that made the whole space open up,but I'm so happy with the new work flow space for two kilns and two Peter puggers. Its a joy to have them all centrally locted in kiln area.
This post is  really is for Mea as she keeps track of so many details and I tend to log them and let them go and now I compare the totals every year.
Here  are the 2023 totals compared to 2022
I also should mention I bisque fire in the car kiln and the Geil not in my electric much
My total cubic feet fired wares for 2021 was 1,305 cubic feet of pots
My total cubic feet fired wares for 2022 was 1,147 cubic feet of pots
My total cubic feet fired wares for 2023 was 941 cubic feet of pots
2023- 35 cubic Car kiln downdraft -19
2022 -35 cubic Car kiln-21
2023-12 cubic feet updraft-14
2022-12 cubic feet updraft-26
2023-NEW to me  this year Geil 18 cubic foot downdraft -6
2023 -10 cubic foot Skutt electric bisques-1
2022 -10 cubic foot Skutt electric bisques-2 
So it really is slowing down and this year is more of that same track as I have cut down my forms list for 2024
It may be not be as much  slowing as one might think in semi retirement mode but I still like clay making its who I am.

if its just been bisqued bisfix will work fine for this. See above video
There are other menders that work as well like Marks mender and highfire mender for glaze wares-I have used them all

SO I just fired my Geil 18 cubic foot kiln  and the 12 cubic uodraft yesterday with this year's 1st fires (2024) and looked up my slow down years total for 2023
I'm loving the new to me Geil-I replaced the honeywell conroller with a longer (gas 90 second pilot hold feature ) hold down feature which makes it easier to light
With the 20 new Bailey 14x28 monster  huge advancer like kiln shelves this kiln really holds more like 20 cubic feet now-I did sink about 15 k into the kiln and shelves and concrete slab job  and  and the 20 foot LVL beams that made the whole space open up,but I'm so happy with the new work flow space for two kilns and two Peter puggers. Its a joy to have them all centrally locted in kiln area.
This post is  really is for Mea as she keeps track of so many details and I tend to log them and let them go and now I compare the totals every year.
Here  are the 2023 totals compared to 2022
I also should mention I bisque fire in the car kiln and the Geil not in my electric much
My total cubic feet fired wares for 2021 was 1,305 cubic feet of pots
My total cubic feet fired wares for 2022 was 1,147 cubic feet of pots
My total cubic feet fired wares for 2023 was 941 cubic feet of pots
2023- 35 cubic Car kiln downdraft -19
2022 -35 cubic Car kiln-21
2023-12 cubic feet updraft-14
2022-12 cubic feet updraft-26
2023-NEW to me  this year Geil 18 cubic foot downdraft -6
2023 -10 cubic foot Skutt electric bisques-1
2022 -10 cubic foot Skutt electric bisques-2 
So it really is slowing down and this year is more of that same track as I have cut down my forms list for 2024
It may be not be as much  slowing as one might think in semi retirement mode but I still like clay making its who I am.

When I am webbing cermaic info I get hits from ICAN but what I need mostly comes from older forum not simi dead (no new info)  called clay art which I was part of as well. More technical high fire info on kiln building and coastings and equipment -less hobby oriented 
Pres Thanks for the weekly work on these questions

if its just been bisqued bisfix will work fine for this. See above video
There are other menders that work as well like Marks mender and highfire mender for glaze wares-I have used them all

When I am webbing cermaic info I get hits from ICAN but what I need mostly comes from older forum not simi dead (no new info)  called clay art which I was part of as well. More technical high fire info on kiln building and coastings and equipment -less hobby oriented 
Pres Thanks for the weekly work on these questions

For 33 year I had used my 3,00 lbs of Kingman feldspar that ran out in 2023 just when The Custar shortage (mine is in bankruptcy and will reopen in future) hit.
I had 4 bags stashed so it was not an issue yet but in last two months I picked up this stash and now will last my lifetime (1,000lbs  in total)
I traded a some moblilezer wax to an old potter friend for a new old stock bag real spodume  from 20 years ago (white bag  in photo)
I'm back to being ok with a potash feldspar and its one less thing to consider.

So in my brief 50 years in functional sales I decieded after about 15 years into it (1985) my favorite colors (toasty  matt browns) did not sell as well as all my shiny crow pots porcelains (crows swoop down and pick up shiny objects) So I switched to shiny all porcelain pottery with bright colors (not my favorites) Since then I sold very well. I have also noticed that in a few areas I traveled to earthtone browns still sold well-not as well as shiny but geographical location does pay a part in this (yes that will take one decades to refine that knowledge ) I sell bright rutile glazes over other colors best (they are a bear to work with and pit and run and one must master all that ) I like a huge variety  of colors and that gives my customers lots of choices from matts to shiny from blacks to blues (blue is my least fav but sells)

I could help better by seeing a burner photo in reguard to burner type

Speaking of sustainability
I have felt bad about my part in global warming for decades using so much fossil fuel (natural gas) as a full time potter.
For me as a Potter I try to offset this in other areas and we all can do some part as each of us has a part to play in this whether it’s simple recycling or an electric car or other small part.
Everything counts.
For me personally I have had a solar water preheater (copper solar water heater panels, two 4x8 panels on roof) feeding into my water heater since Jimmy Carter funded an incentive in 1980 and help me pay for them. They are still up and working today after43 years. I have moved them once and had to keep them serviced and replaced the 80-gallon solar tank once but it’s an active system.
My wife and I personally installed ourselves a 9.6 KW  ground mount solar electric panels in early 2020 as well as a 22.5 KW lithium backup battery system. Yes, I helped raise the price of raw lithium. We did 100% of all the install.
We use a very small amount of grid power and make the rest ourselves from the sun.
Do whatever you can as it all adds up.

60 feet is a long run .It may work just fine. 1 inch is not overbuilt. The burners will tell the story. My soft brick small 12 cubic foot kiln with 6 burners hardley uses any gas. You may be fine -I'm assuming the kiln is all soft brick as well. Updraft? details would help again-photos of kiln burners etc
less bends in piping if you can will aid is flow.
I went back and found your kiln photos-it a what I call trash can kiln -My guess is its smaller than 15CF. (no burner photos). I think the 1 inch will work for that small kiln
 

Most natural gas presures  for the home are 1/4 pound or 7 inchs on a manometer  .
That  works  fine for gas kilns as well. Just hook it up and start firing
If  you ever needed more pressure you would turn up the pressure at the main meter (which you will NOT need to do). The devices in your home stove ,water heater ,furnace etc all have presure devices built in, they regulate the presure to 1/4 lb.
You do not need any other device. Now propand is a whole different anamal.

For me its functional cone 10 porcelain (durable) and the forms are the ones one would use the most. Mugs ,Bowls ,sponge holders ,glasses things one uses everyday.

For me its functional cone 10 porcelain (durable) and the forms are the ones one would use the most. Mugs ,Bowls ,sponge holders ,glasses things one uses everyday.

Pipe sizing is very important at low gas presures. Missed talking about that. Since all my supply is 2 inch from the meter. If you have a long run the size is very important. My Geil needs 1 inch for example .
How long is the pipe run? Most homes are 3/4 inch ,as Bill said we need more info on the spec plate of kiln or siome info on kiln burners and size of kiln?

For 33 year I had used my 3,00 lbs of Kingman feldspar that ran out in 2023 just when The Custar shortage (mine is in bankruptcy and will reopen in future) hit.
I had 4 bags stashed so it was not an issue yet but in last two months I picked up this stash and now will last my lifetime (1,000lbs  in total)
I traded a some moblilezer wax to an old potter friend for a new old stock bag real spodume  from 20 years ago (white bag  in photo)
I'm back to being ok with a potash feldspar and its one less thing to consider.