Chilly

Are you familiar with the Orton cone chart and making the last segment go the speed in the chart for the final 100c of the firing to get the cone to drop?
The center column speed is common so your last segment speed would be 60c per hour and for cone 5, end of firing = 1186c, start of final segment: 1186c - 100c = 1086c.  So last segment starts at 1086c, goes 60c per hour and ends at 1186c. This should get cone 5 to drop as planned.
your first segment can go as fast as your pots will tolerate so approximately 100c - 250c per hour.
It turns out, most of the heatwork is done in the last 100c, so get that right and you can more accurately fire to cone. If you add a hold to the end generally a 15 to 20 minute hold drives it approximately to the next cone.
This way, you always have a place to start working on a “good” schedule.
 
 

I use this 
https://www.axner.com/pure-lube.aspx

Pure & Simple suggest https://cdn.shopify.com/s/files/1/1130/0194/files/INSTRUCTIONS_2021.1.pdf?v=1609298598

an 18x18 concrete patio block works well, can me moved easily and tilted if you find a support for one side.   may only find 16x16,  look at used on craigslist.
 
NO CANVAS!

I get newbies to do a "number of coats" test tile, before they do any glazing or underglazing.  A square of clay, marked into 4 smaller squares.  Corner 1 gets one coat of underglaze, corner 2 gets 2 coats, corner 3............etc
This gets bisque fired and then they apply 1 coat of clear on half of corner 1, 2 coats on half of corner 2..........
Second fire to earthenware, (we don't do any high-fire) then they (I) can determine if they are a light applier or a heavy applier.  This gives them a guide for future applications.    
We often repeat with a vertical tile with texture.

I get newbies to do a "number of coats" test tile, before they do any glazing or underglazing.  A square of clay, marked into 4 smaller squares.  Corner 1 gets one coat of underglaze, corner 2 gets 2 coats, corner 3............etc
This gets bisque fired and then they apply 1 coat of clear on half of corner 1, 2 coats on half of corner 2..........
Second fire to earthenware, (we don't do any high-fire) then they (I) can determine if they are a light applier or a heavy applier.  This gives them a guide for future applications.    
We often repeat with a vertical tile with texture.

My answer is no, after learning the hard way early on! And I've learned that it's best to not try to explain why. Because if someone doesn't take no the first time, they probably aren't going to understand the explanations. 
However, on very rare occasions, I have said yes to people who are long time customers who not only have bought a lot of my work, but I have spent enough time talking to them to know they understand what I'm doing. These requests are always made within parameters that make sense, because like I said these people understand what I'm doing. For me it makes sense to differentiate a select handful of customers into a VIP category, and to do my best to make them happy.
Here's an example. Some long time customers of mine got married, and asked me to adapt my elephant figurines into a "bride + groom" version for their cake topper. I was happy to do this!

I read this post the other day and thought I should just let my thoughts germinate for a few days. Like Callie says it's not really unbeleafable, root of the issue is having a seed land on your slip and left alone for a thyme and given a leaf of faith it will sprout. I better stop now before I'm blamed for disturbing the peas. 

I so agree with you @LeeU.
Time is money too, and hours spent re-hydrating is time I could be doing much more interesting things.  Problem is, I have some discontinued glazes that I love !

From reading your first post in this thread my takeaway is you made a Moon Jar shaped vase from lowfire clay that "the bottom cracked and lost large pieces" that you glazed with lowfire commercial glaze.  Piece went on to be sold and the customer requested a saucer for it which you will make from a new bag of the same lowfire clay, then after glaze firing rub some black mason stain/frit into the texture, wipe down and refire. You will be firing the saucer(s) in "a very big kiln pretty much completely empty several times for this". Is this correct? 
Reason I thought making a cone 6 saucer was a viable choice was twofold, firstly to avoid needing to do a separate firing for the saucer(s) "I’ll be using a very big kiln pretty much completely empty several times for this." Secondly by using a vitrified low absorption cone 6 clay you negate the need for stilting the saucer and glazing it in entirety to ensure it won't weep. I'm assuming that since your customer is using the pot as a planter and is asking for a saucer for it they will be using it as a functional pot and this will be important. Yes, there is some work with getting a glaze match or complimentary glaze colour. This would be my plan B.
How much did the bag of lowfire clay cost? What is the cost of firing your kiln several times pretty much completely empty? Have you tried your lowfire glaze at cone 6 to see if it might work?
Quite honestly I would take the bag of clay and make the customer a new pot that doesn't have the damage the first one sustained during bisque firing. This would be my Plan A. I acknowledge that sculptural work can often have repairs made and those skilled in Kinsugi can enhance a broken pot but from my experience making pots for 30+ years selling a pot with damage such as you described might not be the best idea for what is essentially a functional pot. I can't recall ever seeing a Moon Jar with a saucer as it would distract from the profile of the piece. 
As far as I can tell everyone who made a comment about not caring to do custom work is making functional pots. Yes, there can be sculptural aspects to a Moon Jar shaped vase being used for a planter but it's still a functional pot. For the context of this discussion it is a valid comment. I actually started a separate thread here asking about taking on custom work, as someone making sculptural work your comments would expand the dialogue there if you care to post your thoughts there to add to the depth and breadth of the discussion.
Nobody has said yes to your question because nobody has had success with this method or hasn't tried it. I don't think it would work.

I so agree with you @LeeU.
Time is money too, and hours spent re-hydrating is time I could be doing much more interesting things.  Problem is, I have some discontinued glazes that I love !

Mongoose, Parrot fish,Rainbow Wrase cleaner fish
 

The layout is on beach sand for a background-its an ocean thing .-Worked well for this layout before computers 

I hate rehydrating glaze or reclaiming dried clay. If I catch it early before it accumulates, I'm OK with doing it in small doses--but once the dried glaze/clay began to pile up, I donated it to a ceramics student & a hobby potter who don't mind doing the work to bring it back to life.  I lost the money but considered it a small donation for a good cause and then bought fresh. 

no, you have some  dry clay stuck on the walls inside the tube.   that creates a ragged lump that forces the damp clay to shape itself around the lump.   if you keep pugging,  and use a little water as you insert the clay, it will start to look like a normal straight pug.  normally,  twice is nice for making the clay exactly the way you want it but when you have this situation, you are gathering tiny hard bits of that dry clay in the middle of the pug. 
keep on and keep calm, it will eventually work its way out.  you might cut the chunks through and feel for small hard lumps now instead of finding them in your thrown walls.  there are no rules saying the first pug of the clay is enough.  it is your very strong  machine, make it do what you want.

@larathompson288, many of the Velvets can go to cone 10 without loosing their vibrancy. Useful set of images here that shows the Velvets, each fired to cone 05 on the left, cone 5 in the middle and cone 10 on the right. (Orton cone chart that Bill linked will give you the temperatures for each of those) Super important to test the underglazes with the glaze you will be using them with as there can be colour shifts depending on the chemistry of the covering glaze. Many people use a zinc free clear as a covering glaze.
You mentioned using a stoneware for the plates, what is the recommended firing temperature or cone for it? For dinnerware you want the clay to be as mature as possible for both strength and vitrification. Are you firing stoneware to earthenware temperature? (like cone 05)
 

It’s not the last hour, you fire at the rate of 60c PER HOUR for the last 100c so that will take a little more than 1 hour and a half (1:40 actually). With respect to cones, they are made of glaze and calibrated to show accumulated heat work which happens mostly in the last 100c This is where glaze mostly matures. Silica and alumina without flux don’t like to really melt below about 1600c flux helps things melt. The question becomes when?
Because cones are glaze and glaze melts as a result of fluxes lowering the melting point and time and temperature affects accumulated work, cones more accurately show when a glaze is mature. Because they are made of glaze and calibrated to bend at their cone value.
Think of it a little like cooking, if you leave your pizza in the oven and ignore time and cook it for 30 minutes more than the instruction, it’s probably well over done. Time and rate combine as something called heatwork. Cones are made of glaze and indicate accumulated heatwork on a glaze.
Here is an interesting thought, if I reach 1031c and hold or soak for thirty minutes I now drive this from cone 05 to likely two cones higher in accumulated work or cone 03. Time And temperature affect glaze maturity.
So to answer your last question, cones indicate what happens in about the last 1h40m of the firing, which is the most important part of the firing with respect to maturity.

Speaking of copying  I long ago in another clay universe was a partner in a press mold ceramic pin and magnet  business we (the two of us which at that time was a girlfriend whom we spent 10 or so years together)
This business was concived as business that could fit in a very small space as the kiln was the only large item. We made the originals from clay and I made press molds and she glazed them. We used a small airbrush and very small compressor for glazing. We marketed zoos and aquariums from BC Canada to Hawaii  to the New England aquarium  and all in-between Places like the San Deigo zoo , Montery Aquarium buildt in 1984. Most of the marketing was personal as we went there and talked to them (Hawaii and BC) east coast was all on the phone and via mail.
I was alaways into fish from diving with them. My brother did the color layup master (a cibachrome) for us (he was a Art Professor at UCSB in Santa Barbara  and did cibachrome all the time back then) and had access to color equipment . Once I had a master I had a company print the color layouts
I have a few left even though this was all over 40 years ago-just a layout no price lists anymore. The  business was good for about 5-7 years and we moved on to other projects. I still have tons of pinbacks and magnets
 Now to the copyright  part of this story
At this time I was doing shows in the west coast callled harvest festivals in the late 70s early 80s and many clay folks where making ceramic pins I learned from them about copyrights.
We choose trhe cheaper copyright  path that many where taking and that is stamp the backs with the copyright logo  on pin backs and hope folks respected that. It worked and we never had any infringement that we know of. Her is that master cibachrome and final  color sales brochure. I still have a few magnets on the fridge of the more durable forms. We had 20 formscan you name them all? My guess is there are a few most do not know
The business was called Coruba Pins named from this rare rum label that I once enjoyed drinking -not much of a dinker past 40 years now.
Man I have done a lot with clay -most of this I had forgotten until this write up.
 

HAPPY POTS
i had a venco  without a vacuum and got a bailey with vacuum later.  i believe that the bailey has a cap for your vaccum area that will fit.   the one you show seems too big for that venco.   contact jim bailey with your measurements to see it his will fit.   you should be able to just buy that cap with it's own gasket attached.    ask him about the meter attached to the top of yours. 
just call on a telephone and talk to him, do not send emails.  they really do not work for this kind of info.

Bisque fix fires out white a pretty Bright white. So if it brown clay it will be very visible. If you want a product that blends in better vis wise  use high fire mender which you mix with your own clay for the best color match

Two suggestions from Anglian Potters - NFU and https://www.a-n.co.uk/about/insurance/

spot on. denice!    IFa beginner has found this forum, they have at least found a lot of information that is in the very first section.   start with the glossary.   learn the proper terms for what you want to ask about.   learning to read starts with the alphabet, the glossary has that alphabet for you.   get some old books, the 70s was a time publishers did a good job with what became textbooks.   yes, things they made might not be what you want to make but the basics is what you need and that is covered.
there are posts on here about " What is on your bookshelf?"   if you can find that original question, you will have quite a good list to start with.   see how things are DONE!  ignore the final results that would be something you would never make..     remember you are learning a skill.     do you think those fabulous figure skaters started out throwing or being thrown many feet in the air without seeing a description of how it is done?
and do not ever mistake cone 06 for cone 6!!!   now, go to the glossary and look up what a cone is.
 

I think trying to learn pottery without proper education is like the people who think they can rebuild a house without any experience or training  in the trades.   Plumbers, electrician and carpenters have gone to school and spent years of training ,  the same goes for potters.   I wouldn't dream of telling my electrician that I can wire my own kiln because I watched a couple of video's.  I have even had a few people asked me if they spent a couple of hours in my studio they could learn how to make tile  they way I do.   The first thing someone told me to do when I decided to get serious about clay was to buy some books they recommended and study them.   That was 50 years ago and they are extremely out of date now but I am sure there has to be some books out there that would be a good start for a aspiring potter.    Denice

I'm coming at this question from one of the things I made a mistake with when starting out. I had taken some ceramics classes as a kid and loved it, fast forward a number of years and after my fourth child I had some postpartum depression and needed to get out of the house. Local rec center had pottery classes which I signed up for without knowing anything about the instructor. Big mistake! No end of things the instructor did incorrectly (including sieving a bucket of glaze materials dry, in the class and with no ventilation system or masks). I was the only new person in the class, everyone else had taken classes with the previous instructor who was great but was no longer working there, they all just used the class time to work on the wheel or handbuilding but didn't glaze anything.  New instructor had no knowledge of the glazes and gave very little instruction on how to throw pots. It was very discouraging to say the least. 
Back to the question of the week, if I were starting again I would vet the sources I'm getting info / techniques from. Really not helpful to watch someone throw a pot or give advice if they don't know what they are doing.
Oh, and one other thing, don't cat lick your pots. 

Simply posting a link to another thread isn't a question.
The first link is to a quiz on kiln design terminology. The answers are in the first post in that thread! But the answers can also be deduced from the majority guesses given in the replies.
The second link is to a survey request on "sustainability in your ceramics practice" that doesn't seem to have generated a significant number of replies (probably because it was far too open-ended). Hard to see what the question could be.
This thread is about "dishwasher and microwave safe pottery".