neilestrick

My wheel and primary work table are set for standing. Occasionally I will sit on a tall stool while decorating, but for the most part I do everything while standing. Back when I set up my wheel for standing I realized just how much of my energy was going into getting up and down from a seated position. Working in a standing position I can move about more and take advantage of a larger work area instead of always moving things into and out of a small seated work area.

In my experience, very few people are affected by the molds in clay. I've spent 8 years in University studios, 3 years in a clay supplier business, and 17 years teaching classes in my own studio, and I've only run into two people that had to drop classes due to mold sensitivity. I've got students with immune deficiency conditions (I don't know the specific conditions) and it doesn't affect them. Mold is unavoidable in the clay itself, short of mixing your own clay every time you go to work with it, which would be very poor clay to work with. And doesn't seem to be the type of mold that causes strong reactions and health issues like you'd get in moldy drywall. If it was we'd all be experiencing health issues every time we opened a bag. I think that testing a bag of clay for specific molds would be useless because the clay body materials are sourced form different places and you would/could get different spores from every batch of raw materials.
The studio itself is a different story. There's no reason it should be any more moldy than any other environment due to the clay itself. If your local studio is musty, I'd first determine if the issue is the clay, or something else like a damp basement, etc. Just using clay in a space shouldn't contribute to the mustiness if the space is dry in the first place, because the mold needs moisture to proliferate. If the smell is from slop buckets or standing water in the sink, those issue can be easily dealt with. However I've got open slop buckets in my studio, and we do not have any oder or mustiness problems from them. If we did, then lids would solve the problem there. 
Personally, I'm allergic to molds in the environment, and my allergies are always a mess in the Spring when it's rainy and in the Fall from leaf molds. The studio environment never sets them off, though.

this will make the surface rigid-you can spray or brush it on fiber (I spray it with a mask on)
pretty cheap stuff -also called ridgizier
thin coat is best
https://www.axner.com/search.aspx?find=RF+458
 

http://www.ktrefractories.com/hightemp_coating.cfm
https://www.ceramaterials.com/fiber-glue-rigidizers/
Suggest:
Search refractory coatings rigidizer..

A flaking lid is definitely a problem, but replacing it with a brick lid is not a cheap fix. A new lid slab plus shipping will cost $300-500 depending on the size. Or if the floor is the same material and in better condition then you can swap them. They also make products that stabilize and harden fiber that may help. Is the lid still structurally sound? Unless the lid has degraded considerably, I wouldn't think it would be the cause of the kiln not getting to temp. The other issue with flaking fiber is that you're breathing those fibers every time you move the lid, and that's not good for your lungs.
You can make your own lid slab, but unless you've got some experience mortaring insulating firebrick it may not go well and you'll waste a lot of time and money. New IFB run $4-6 each. Cutting the slab to size and shape is a big mess, lots of dust. The other issue is that the hinge on the kiln is probably not made to support the weight of a brick slab, so you'll need a new hinge system, which would have to come from another brand. You'll also need an outer band for the slab. All in you probably won't save much over getting a new one. If you can find a junker kiln locally that someone is selling cheap, you can use the slab and hinge from it.
Honestly, sometimes kilns just need to be tossed out.
 

Standard #365 cone 6 porcelain.

Nah, I just don't clean my splash pan very often. That mess is from a lot of pots.
I work with cylinders rather than sausages/coils. For these I throw a 7# base slab with a 1" tall wall, then stack two 12.5# cylinders (all while wet) and pull and shape. After it stiffens up a little bit, I add another 12.5# cylinder to finish it off. So 45 pounds total.


 

Mine is about 30 degrees off at cone 6, about 10 degrees at cone 04. No voltage issues, plenty of power. I've had several customers in the past 6 months experience the same thing. I think it's just a difference with the programming in the controller. I even used my old TC blocks just to see if that made a difference, since they have a different terminal material.
@Pres If you plan to do your own program anyway, just run a firing with cones you can see, and shut the kiln down manually when the cones drop and use that temp as the peak for your firings. That's what I do for my glaze firings.
 

Mine is about 30 degrees off at cone 6, about 10 degrees at cone 04. No voltage issues, plenty of power. I've had several customers in the past 6 months experience the same thing. I think it's just a difference with the programming in the controller. I even used my old TC blocks just to see if that made a difference, since they have a different terminal material.
@Pres If you plan to do your own program anyway, just run a firing with cones you can see, and shut the kiln down manually when the cones drop and use that temp as the peak for your firings. That's what I do for my glaze firings.
 

That sounds normal to me.  It's just a simple squirrel cage blower, so not the most advanced  blower technology. When they go bad the bearings wear out and they make a lot more noise than that. I couldn't hear it in the video, but if you're getting any additional noise from vibrations in the wall, you could put it on the floor on a piece of foam to isolate it more.

The holes won't affect the firing.

If the existing motor is swapped for a inline fan with similar CFM but the rest of the system is used as-is, no further modifications would be necessary since the mixing is done at the collection cup under the kiln.

The can handle two kilns, so yes on one kiln they are starved. They work, though. Thousands of these out there functioning as intended...

That sounds normal to me.  It's just a simple squirrel cage blower, so not the most advanced  blower technology. When they go bad the bearings wear out and they make a lot more noise than that. I couldn't hear it in the video, but if you're getting any additional noise from vibrations in the wall, you could put it on the floor on a piece of foam to isolate it more.

You won't get all the elements glowing unless it's on high.
Get yourself an inexpensive digital pyrometer and a heavy duty (8 gauge) type K thermocouple from Amazon and stick it in the spy hole to track temperature rise.

That sounds normal to me.  It's just a simple squirrel cage blower, so not the most advanced  blower technology. When they go bad the bearings wear out and they make a lot more noise than that. I couldn't hear it in the video, but if you're getting any additional noise from vibrations in the wall, you could put it on the floor on a piece of foam to isolate it more.

Neil, thank you for the heads up on Euclids. I'll check them out. 
There's actually 8 gauge wire in the ceiling, but when the electrician saw the kiln sitter (like you said) he wanted to come back and rewire with 6 gauge. It sounds like the 8 will be fine for this kiln, thankfully. 
To be honest, I'm going to have to read your and Dick's posts through several times before I feel like I really "get it." Part of it is that electrical is so over my head, and part is brain burnout from freaking out all day because I thought $1500 went down the tube. 
Thank you both for your replies. You brought some hope to a super stressed out lady. 

Skutt does the graded elements to compensate for the fact that most of their kilns are single zone, and the controller doesn't know what's happening in the top and bottom sections of the kiln. It's not nearly as precise at keeping things even as zone control, though, so you still have to be careful how you load the kiln. If you run zone control with graded elements, the top and bottom sections won't have to work as hard as with equal elements since they're running hotter. The total power consumption would probably be about the same, since the total wattage is the same with either setup. It's hard to estimate just how much of a difference it would make. I think it would take a real world test to find out. My gut says it would be more like 75% instead of 85%. I think to get them all to run totally even, you'd have to have a drastic power difference between the middle and the other sections.
The Skutt 1231PK runs 3 different elements. I think some of the older Cress kilns do that, too, even on 27" tall kilns.
L&L has always run equal elements because it greatly simplifies everything when it comes to elements. No worries about getting the wrong elements in the wrong place, etc. And as a repair person the math is easier if you need to calculate element resistance on the fly. TBH, I haven't noticed the middle section elements wearing that much differently than the top and bottom on my L&L kilns, and I've always gotten about 150 firings between element changes, so it's not really a big deal. I think that just being in the heat degrades the elements a lot, even if they're not working hard to create the heat.

You can still fire by color if you want to. Set it to cone 7 medium speed, then manually turn it off when it hits the color you want.

I understand that I can do things like that. I believe that I will have to see what the present settings do, look at what I see going on, and then set up some sort of custom setting that allows me to fire up, and fire down the way I was used to doing it. I knew that there would be a learning curve, after all it took me 25 years or so to get to where I could fire the old one intuitively. Hopefully this one will not take that long!
 
best,
Pres

It's always time to get the banjo out. 

Feels weird to self-quote, but this made me think of a phenomenon we see in wood burning kilns and sometimes in gas salt kilns, too- kilns that have hard brick interiors. There's often a point at which the kilns stall out, where the mass of the bricks are sucking up all the energy. Then, once the bricks become saturated with heat they start radiating and the kiln climbs easily.
In grad school we had a shino kiln that had 18" thick walls- 9" of hard brick interior and 9" of soft brick exterior. The idea was that you'd fire really slow, like over two or three days days so the hard bricks got super saturated with heat, and then it takes days for the kiln to cool, which gives great color in shino glazes. Anyway, my fried was firing the kiln and had it climbing really slowly. After a day or two the kiln was at about cone 6 and should have continued for another full day at that rate of climb, and needed turning up a couple more times. So he went home and went to bed that night and in the morning the kiln had flattened cone 11. We figure it got to cone 14 or higher. The bricks had become saturated and the kiln rocketed up.
Anyway, this just popped into my head when I was looking at my firing reports.

I like it! Backs up the theory that slow is sort of everything for more even firing.  As far as more energy it’s still the shell losses and the mass of the kiln so that makes complete sense to me. At lower temps the difference in energy between the elements and everything to be heated is greatest, so that and a relatively fast rate has to be some sort of exponential relationship. Later the elements and wares are closer in temperature while shell loses are close to a linear percentage so easier to maintain a slower rate...... as long as the relays can cycle fast enough. That old ten second minimum was likely there to save relays and also likely helped prevent some overshoot in the early stages but may have caused some undershoot later on made up by longer relay on time.
The percentage activation is golden and is a nice indicator of the loading. This process from basically zero to 2000 is tough to tune as it’s changing significantly and loading changes the effect on the zones. Anyone who has spent an afternoon tuning a pid module for something simpler would understand.
The lid makes total sense to me and aligns with IR camera stuff we have taken as well.
We should take the data and curve fit it ............. why? Geek alarm, never mind.
Nice data, thanks again!

The SSR's are really good at keeping it even. In looking at my last few firings, the temp difference between the 3 sections during the final slow rap is never more than 2F degrees. During the faster ramp it's mostly even, but in every firing there's a couple hundred degrees at some point where the spread gets to 10F degrees. It's interesting to see how that varies from firing to firing.  Sometimes it goes uneven at 1600F, sometimes at 1900F. It's clear that how each batch is loaded affects what happens during the ramps.
I was also surprised that during the final 108F/hr ramp the relay % doesn't vary much over the 200 degrees. It's only 2-4% difference. I would have thought it would be working a lot harder at the peak. 200 degrees is a big climb, after all. I suppose that during the slow ramp the bricks and ware are much closer to the air temp, so they're not just sucking up every bit of energy the elements put out and the elements don't have to work nearly as hard to make gains in temperature despite it getting hotter. I've also seen in several firings that the top section is clearly dealing with heat loss out the lid during the final ramp, as it tends to increase more than the bottom and middle by the end of the ramp.
It's fun to geek out on a spread sheet!

Time to get your banjo out!