Rae Reich

To leak slowly.
A quick test is to fill the teapot and leave it on a paper towel overnight. The towel should remain dry.

This is glaze crawling, happens for a few reasons but in this case it looks like the glaze was applied to heavily. Other reasons for crawling are dirty bisque (hand lotions/oils etc on clay) or a high shrinkage of the glaze from materials within it having high loss on ignition.
As long as the clay doesn't weep from too high an absorption the teapot will be fine to use.
Nice looking teapot.

Refires are always crap shoots but if you don't have anything to loose it's worth a try.
I'ld suggest that if you have some thicker glaze (from the side of the bucket where the glazes dry out) take some of that and get it on the bare spots then refire in the coolest part of your kiln.
 

There are always qualifiers. An air gap can help because it allows cooling. If there is no cooling then everything is going to warm. The example of the restaurant fire starting because of the bolted penetrations was a new find at the time. 
Manufactures will always defer to local codes. NFPA often will take precedence or be cited in mechanical codes, there will always be qualifiers so a distance measurement is always dependent on local cooling. Again, real fire proof construction as in metal studs, layers of drywall - proven conservative methods ….. nothing to burn. 
Cooling is always an important part of the equation and most methods rely on being cooled by the ambient air temp ……. Except for non combustible construction practices. Everyone will attempt to defer to the manufacturers and manufacturers will defer to local code and local codes are often adopted years after publication. 
Most locations may be using 2020 mechanical codes yet. It’s not really fair for manufactures to be 100% accountable for some random kiln enclosure. The UL test and certified spacing assumes the interior space will not be greater than 100. It’s my suggestion to be conservative and cautious. If there is a minimum distance it’s likely qualified by ambient air temp.  Be safe, don’t try and design your own, if you do though then I suggest diligent common sense should be exercised. Measuring the actual temperature is a very proactive and an impressive double check on your part IMO.  Now likely time to improve the setup a bit.

This may sound strange to you but I have no code or formula . I just dump some carbanate in a jar and add a bit of water until it feels/looks right. No measuring. I never measure  homemade stains its always by feel no matter if its  coblat ,rutile or Iron. I do stir it up constantly and never add a flux or gum. My thought is  its one more thing to burn out and make for crawing . If you add flux that can also make the drawing move more and get blurred is also my take. Once dry I glaze with a very thin clear glaze and fire hot (I'm a cone 10 potter) . Using the right brush is also a key point

Wow, warehouse volume of cooling and made it to 160? Too close for me actually. I have to assume natural cooling so fairly dependent on outdoor air temperature. I think this is the common sense part and seems too close for my comfort. Fail safe ventilation would be something I would definitely add to make sure a minor change in outdoor temp or someone accidentally leaving a door closed doesn’t let this increase. Guidance on distance from paragon is reasonable but I believe all the major brands have guidance on accounting for HVAC (cooling / ventilation) now in their setting up a kiln room docs.
Just looking at old L&L docs bases on 2000 mech code, looks like they were citing less than 160 degrees.

I have finished the third firing. On the second one I have put 36 lbs on bottom and medium shelves. For bottom shelf 06 and 05 cones are fully collapsed. I'm waiting for the kiln to cool to see the results of the third firing which included some bricks with both stretcher and header (vertical) glazed. Tomorrow I will do the fourth one.

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We haven't bought from them yet; if we do, I'll follow up with a review.
Sometimes, there's vendors that have great pricing.
See, for example, D. Lawless Hardware for cabinet bits - hinges, pulls, etc. 

Thanks, Tom for that site referral. I checked it out and the price for a cover for my Raku kiln was less than half for the same dimensions at the Coverstore!

I just did a quick google search, and came up with a 2yo Reddit thread that was warning people against this University. One of the Mods there noted that a lot of the positive comments about it came in months after the initial query (same question as yours), and appeared to be only from commenters who had made accounts to reply to that one post. Other posters noted the same pattern on Quora and other similar sites. So I’d be cautious about that particular source, but yes, getting some marketing and business courses is definitely a good idea.
Accounting doesn’t have to be terribly complicated or expensive. I’d pay an accountant to set you up on how they want you to keep books, and let them do the rest. Mine gave me a spreadsheet to fill out quarterly, and she does my filing. 
Some simple marketing courses through university or college extensions should be sufficient for that part. You don’t need a degree in this. You need to be able to make connections with other potters to be able to discuss what works and what doesn’t. We tend to do a lot of non-traditional/non-standard things in our business.
As far as business courses go, I think you should put together a business plan for your own benefit, but you don’t need one that you could take to a bank for a loan. At least not if you’re a one person operation. Again, that could be an extension course, or even just hit the library for some books. People aren’t vetting your business degree before they buy pots from you.
 

From what I can see they are most all connection issues and also to wet and to thick issues for the speed of the firing cycle.
More slip and scoring when connecting (more pressure and both pieces need to be same moisture) less thick walls will help. get the work dryer and slow firing is best especially for thick work.

After reading @Callie Beller Diesel's excellent review, there are a few questions I would ask.
First, referring to bone dry. That term is really quite relative especially if you live in a high humidity climate, or if the drying occured in Summer/Fall  months where things are usually more humid. If very humid, I would always extend my candle time. I used to fire my kiln without a setter and would use a simple test to see if the kiln is ready to move out one heat range to another. Place your dry open  hand over the open peep hole to check for moisture. If your hand comes away slightly damp then the pots are still too damp. Wait until you no longer feel moisture on your hand. Then check on the next level turning up your kiln until you have no moisture feel on your hand. On assembly, you say you use paper clay to assemble. Have you ever tried Magic Water? This simple material is made up of  1 gal. of water, 3 tbsp of liquid sodium silicate & 1 1/2 tsp. of Soda Ash.  It works very well to  join pieces of clay that are in the regular working stages of cheese hard to leather hard together. Far superior to any slip, and a much cleaner join. I would really try it to see if can help you with your joins. best,
Pres

I think the images have been uploaded in the reverse of how you talk about them. To confirm, I’m reading the items that appear at the bottom of your post as what you refer to as 1 and 2, which are a bowl on a small pedestal and a vase with a lobed neck. The one at the top (5 photos) is what you refer to as the third piece, which resembles a cup with a stem. (They’re very cool, btw!)
I don’t think the sharp right angle is contributing to the cracking in these pieces, although it can lead to surface cracks in those areas. The images of the break on #3 gives some good insight on your working methods. Because you can see the score marks where you made the attachment, that means the pieces weren’t properly adhered to each other. Even with paper clay, you still need to wiggle the pieces against each other until they stop sliding to ensure a good join. Especially when joining major structural elements that hold a lot of weight. One of the pieces might have also been too dry for the other.   
Because the clay is discoloured in the center of the goblet piece, it would indicate that organics didn’t have enough time to burn all the way out. Unless your kiln was a gas kiln and not vented properly, the early half of the firing was likely too fast, especially if there was no other work in the kiln. The easiest way to fix this is to build the base hollow, so that the piece can fire more evenly. 
However, if you need the extra weight for stability, you may have to slow down the first part of your bisque cycle to 80* C/hour to 550, and possibly add another 5-10 min to the first hold.  Firing the piece on a waster slab, or some kind of refractory sand (silica or alumina, or even grog/chamotte) will help relieve the stress on it as it expands and contracts through quartz inversion. 
 

see also coversandall.com

If you want to spend some $$$, You can go to www.coverstore.com and use code DE7UM4RS for a 25% discount. They have covers for all kids of items and they do custom covers, too. I got one for my golf cart.

You could probably customize a cover with some vapour barrier and duct tape, if you ‘ve got any kicking around.

@Rae Reich thanks! I’m planning on switching the wood shelves to hardibacker pieces. Will try to diy a cover. Appreciate the ideas!

Hi Alan and welcome to the forum.
Iron tends to get bleached out by the calcium that is found in most cone 6 glazes. I don't know what is available on your side of the pond but you might want to look at using either a brown underglaze, or a brown and black mix of underglazes, or a ceramic stain mixed with a frit to help it adhere to the pot plus some kaolin.

In the absence of a better guideline, most people compare leachate values to drinking water standards. The accuracy of doing this is up for debate because pottery isn’t your plumbing pipes, but it’s at least a starting point. Your leachate value is going to decrease with an item’s use, not fluctuate like drinking water running through miles of pipes. It’s further complicated by the fact that you drink acidic beverages out of some containers which might ….you get the idea. 
The Government of Canada has an Aesthetic Objective recommendation of 1 ppm of copper for staining and smell/taste, and a maximum value of 2 ppm for health purposes. Your leachate value is well under both those numbers. 
The US EPA has an “action level” of 1.3 mg/L, or 1.3 ppm for copper. You’re well under that too. 

The bold heading is your results of 0.207 micrograms per milliliter and if you multiply the total volume of leachate (acetic acid) 192 x 0.207 you get 39.744 or 40 micrograms total. The reporting limit of 0.005 is the lowest values they can accurately report.
 
In this they say there's no legal limit for copper but 1.3 milligrams per liter is safe for drinking water and you have 207 micrograms per liter or 0.207 milligrams so about 15% of what can be inferred as "safe"
https://ceramicartsnetwork.org/ceramic-recipes/recipe/Copper-Oxide#

A bit of cement board held off wall  a bit would help any kiln situation to keep walls cooler

Just double checking your problem, you added 3,000 of whiting instead of 2,000? All other ingredients added as stated, including 3,000 silica? If this is correct then you added 50% too much Whiting.
Not a math genius either but this is what I get...
Add the following to the bucket (hope you have a big bucket)
3134  + 700
C&C + 900
NepSy + 900
Silica + 1500
Bentonite + 100
edit: Just reread your post, add a total of 4500 silica to the bucket. (3000 that was supposed to be in it plus 1500)
 
 

It could be thickness of the paper you are using that is part of the problem, how thick is the paper you have tried? Manila folders or tar roofing paper are both fairly thick and leave a good impression. Also, if your clay is too damp try either leaving the slab dry out a bit before rolling the paper onto it or try dusting it with cornstarch / cornflour.

I’d place good odds on that kiln being a gas fired one meant for metallurgy, not an electric pottery kiln. The ones for knives etc are small and relatively easy to make with a few things from a welder’s supply, but depending on the maker they also can be haphazard affairs. 

Kiln to close to combustibles just like a water heater to close to combustables = fire
Ok its a human thing