Rae Reich

Generally, pouring all the water over all the dry can result in a lump of dry stuck to the bottom of the bucket which is a bit harder to mix in - @Kelly in AK’s solution is another instance of patience doing the work while we do something else.

We call that color ‘snot red 

Generally, pouring all the water over all the dry can result in a lump of dry stuck to the bottom of the bucket which is a bit harder to mix in - @Kelly in AK’s solution is another instance of patience doing the work while we do something else.

A thought I’ll share: As soon as I get the powder into the water bucket I put the lid on and go do something else for a while. It lets things get hydrated before mixing, but mostly I do it to reduce dust in the air. 

It’s a regular occurrence, as @Min said. I have done it many times. I have two experiences worth sharing here though. One is that a person who does workshops where I live asked that no porcelain be glazed and fired the same day because she had something blow up in a workshop. The second is in my wood kiln I had a freshly glazed piece blow up, it was near the bag wall and made of fine grained clay, porcelain like. If it wasn’t my piece and I hadn’t glazed myself I wouldn’t have believed it. I would have chalked it up to someone glazing greenware. I’d never seen a piece of bisque ware explode and haven’t since.

Every group raku firing I have seen does this. Usually freshly glazed pieces are placed on top of the raku kiln to warm up while the kiln is firing, taken off the top of the kiln before it's opened up then put in as the kiln by one person while another is unloading the kiln.

Another technique some use  for later is to mix up a copper red glaze for reduction and place samples throughout the kiln to see just how well you reduce and maintain it. This oxblood color goes ugly green / grey pretty quickly with any sneaky oxygen infiltration. It teaches the importance of keeping the kiln in full reduction top to bottom while providing a way to map the reduction performance within the kiln. Only a handful of metals are significantly affected by reduction btw.
 

Hi Neil;
I always thought if you get a flame out the top, it meant that you had a reducing atmosphere in the kiln?
Good idea on the clay color, when I do a real firing I will know how much reduction I got. I use a lovely iron-rich stoneware clay that gets nicely buff colored when it's reduced.
Richard

I've taken to using the web between the pointer finger and the next finger to compress lips. No extra reaching!
 
best,
Pres

A credit card, pinking shears, and some nice gloopy slip did this. 

Old credit cards make good bench-scrapers and ribs. They can be cut into any profile  needed for shaping and trimming pots, smoothing seams and surfaces. Notching the edges of the card will give you many kinds of texture possibilities. 

Hi and welcome to the forum.
Somewhere to start might be looking at Terra Sig with added materials such as salt, soda ash, oxides and stain and borax. Washes would be another avenue to experiment with. . Also have a look at Mary Fox’s work where she uses lithium carb plus copper for a dry surface. (on some of her lowfire sculptural work)
This articles from Pottery Making Illustrated might be a good place to start for alternative surfaces. It’s behind a paywall but you can access 3 free articles a month.
https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/In-the-Studio-Washes-and-Patinas#
Perry’s wash recipes are for cone 10, for lower firing adding flux would probably be necessary for some of them. Also, firing in oxidation rather than reduction will make a difference with some of them.
http://shambhalapottery.blogspot.com/2013/03/happy-st-paddys-day.html
Pit firing would be another avenue to explore.
 
 
 
 

@Retxy How much of what we're seeing is rusted metal vs old clay? If it's all metal, then the metal is in really bad condition and I wouldn't touch it. If we're looking at a bunch of clay on the surface and the metal underneath is still decent then I think sandblasting is probably the best way to go. Do not put any sort of coatings on the auger or in the hopper. They won't survive. Just leave the interior raw. Paint the exterior if you want to.

I just found a place nearby that can both sandblast and powder coat but if cheaper alternatives exist, I welcome them. Thanks!

Old credit cards make good bench-scrapers and ribs. They can be cut into any profile  needed for shaping and trimming pots, smoothing seams and surfaces. Notching the edges of the card will give you many kinds of texture possibilities. 

Old credit cards make good bench-scrapers and ribs. They can be cut into any profile  needed for shaping and trimming pots, smoothing seams and surfaces. Notching the edges of the card will give you many kinds of texture possibilities. 

Friends! I am happy to report a successful Cone 10+ firing in my mystery kiln! I have attached a picture of my cone packs at every level, with Cone 7, 8, 9, and 10 from left to right in each cone pack. Top of the kiln hit a hard Cone 10, and the bottom of the kiln just liquified all the cones. To fully liquify the Cone 10 like that, I am guessing I might have reached Cone 12+ on the bottom? Hard to be sure.
First, using no damper, I fired the kiln up to about 2100 F by having my gas pressure as high as it would go with no standing flame from the vent. I wanted to see how hot I could get with an oxidizing atmosphere. If I avoided any standing flame from the vent, the kiln seemed to stall at around 2100 F. 
Then I slowly adjusted my gas pressure upwards and used the pyrometer to simply make sure that kiln temperature was increasing. I started to get a small standing flame from the vent, but I ignored it. I just watched the pyrometer. Every time the kiln stalled, I increased the gas just a bit. It was a painstaking process, but by making tiny adjustments to the gas pressure, I was able to hit a max temp of 2303 F based on my pyrometer. Less gas would make the temp start to drop. More gas would make the temp start to drop. So with no damper, I had found the optimal gas flow rate to maximize kiln temp.
Note that at this point of maximum temp, I had a significant standing flame coming out of the vent (see picture). That means my kiln reached peak temp with enough gas flow to have significant reduction going on. This surprised me - I had assumed having extra unburned gas flowing through the kiln would cool things down, but the data was clear - I reached peak temp with a nice standing flame from the vent. 
I then did some experiments to test out the effect of a damper. Keeping the kiln stalled at that peak of 2303 F, I slid the damper on just a fraction of an inch. That made the temp drop. If I slid the damper on more, that just made the temp drop more.
I took off the damper and got back to 2303 F, and then tried sliding on the damper while simultaneously decreasing gas pressure. I assumed I would be able to play with more damper/less gas and maintain the peak temp, but it didn't work that way. The damper made the temp drop. Deceasing the gas made the temp drop. I could not find a combination of more damper/less gas that reached my peak of 2303 F - every combination of conditions was cooler. 
So that part of controlling the kiln is still a mystery. I blew past Cone 10 with no damper and a significant reducing flame coming from the vent. Any use of a damper made the kiln cooler no matter what else I did.
Given my results and what I described, I would appreciate thoughts on how to play with that damper/gas flow combination of factors.
In the meantime, I can certainly get this little kiln to Cone 10 temp just by adjusting the gas flow!
Thank you to everyone that's been reading my posts and giving me excellent ideas and suggestions on what to do.
 
 
 

If you can’t get proper pottery plaster for a reclaim slab, you can lay an old sheet over wire racking and lay thick slurry out on that to dry. 

Since you have a deadline, it may be impossible to remake the piece in time. In that case, I would go ahead and fire the piece. Those cracks are not likely to expand to the point of destruction unless additional stress is put on it during the firing. You may need to accept the modifications to your piece as part of the process, maybe even emphasizing stress lines with glaze or coloration to incorporate them - an “I meant to do that” approach 
If there’s a possibility of completing a new piece in time (using and improving on what you have learned so far) I recommend that you make two or three at the same time as insurance, or at least the greater likelihood, of a piece completed as you envisioned. And maybe you’ll have a series! 

I have used  kiln posts on their sides frequently.  Sometimes the side measurement gives you just the right height that you need.  No Problem.  Lin

No offense intended - I agree with you.  Some folks in our community studio thought it was an issue (which I thought sounded off base), and I just wanted to make sure.   

You do know this all predates 'manufacturers', right?  People have been using kilns and kiln furniture for thousands of years and reusing the same basic materials to do so.  But if in doubt just call your kiln manufacturer.  You don't have to take our word for it.

Yep!  Position them ANY way you like.  I often use them on their sides to stilt pieces up off the bottom of my kiln if my equine sculptures are on bases.  Without airflow, the larger bases in direct contact with the kiln floor can retain a LOT of heat where as the slim legs above may cool too fast and cause the pieces to break.  You may also stack your kiln posts to 'build' walls.  I also have an assortment of other kiln furniture that was given to me but here's a really sweet tip.
You can buy materials to MAKE YOU OWN custom kiln furniture and stilts.   I've done this in some cases where I really need special shapes and then added various thickness of Kanthal wire to run up into pour holes or whatever for especially delicate pieces that would other wise fall over during firing.  Or you can skip the specialty materials if you need one use supports custom fitted to ware by making 'setters' instead that can shrink with your pieces, such as used with porcelain bodies.
Anyway, I digress.  No harm at all in utilizing your kiln furniture turned this way and that, or stacked.  I've even used bits of broken shelves that were given to me for nothing and busted them up to the shapes and sizes I needed.  You can even get or make  'kiln beads' that you can box to form customized supports and nestle ware down into.

It's not just a knob. It's specific to the Sitter, as it has a piece on it that triggers the shutoff. Google 'kiln sitter timer knob' for sources.

Thanks! Your maintenance manual here https://aakilns.com.au/pdf/Duncan_Kiln_Service_Manual.pdf but if you have never fired a manual kiln, there are some steps to learn and detailed in the operating manual below.
This is a 24 amp kiln and the manufacture specifies 30 amp breaker, 40 amps is too large per the manufacture and North American Code.so this should really be protected with a 30 amp breaker Page 58 of 75 in the maintenance manual, bottom right corner of the electrical drawing show amperage, wire size and breaker 
This is a manual kiln that requires the safety countdown timer be set for some period greater than the time it will take to fire. So if the firing is expected to take 8 hours, the timer must be set to something greater such as 9 hours. It is for safety and if it is on or reaches zero your kiln will shut off. Did you set the timer for something greater than zero when you tested? The kiln sitter to be activated  using an appropriate cone and then arming it by depressing the plunger  Page 7 and Page 28 -33 Did you place a cone in the sittter and depress the plunger? Finally the two knobs are turned up gradually throughout the firing (they are know as infinite switches )such as two hours on low, two hours on medium and finally to high until the kiln sitter shuts off the kiln. Page 21 - 24 The manual above provides maintenance for all the components, operating this kiln is better described here https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/LX851_Duncan_Energy_Saver_Owner_Manual.pdf
Last note, this kiln is rated to cone 8 if firing to cone 6 routinely you will get a moderate number of cone 6 firings before the elements will need replacement. Cone 10 rated kilns provide considerably more firings before element replacement when routinely fired to cone 6. The maintenance manual has element resistance measurements listed. If the elements have risen by 10% in resistance, it’s time for replacement to make cone 6 temperatures.