Neither Jim nor I came anywhere near saying something like that (above) to you. I'm sorry if you felt that way, but that was perfectly sound and useful advice given the nature of what you described. And it was not stated in a particulary negative way either. Sometimes really good advice is not what you want to hear. Being "under the gun" and doing something that you've never done before on the basis of some untested recommendations from books or forums or friends is akin to going to Vegas and "letting it ride on red 22".
The prudent thing to do research / listen to the advice.... and then TEST before commiting to something that matters. The phrase "under the gun" you used says it mattered. But some pople DO go to Vegas and play roulette.....so to each his or her own. All any of us here can do from afar is try to help. It is up to the individual to accept or reject the ideas presented.
I too often see students getting ready for their senior thesis shows suddenly decide to try something new on some pieces slated for the show with no time left to re-make the work if the firing does not work out well. Sometimes that Vegas roulette wheel favors them,...... most times not. Drives me nuts when I see them do this. But they usually learn from the mistake .
The reason that the "It depends" answer to everything about ceramics is always correct, is that there are a HUGE number of variables that we are manipulating/controlling throughout the process. Many of those variables affect the results. Many of those variables are critical to the results. Miss one detail in giving the "advice"..... and the results will not be what one expects. So taking in advice and then testing is THE way to get the ends you want.
In a field like medicine, it would be very difficult for a skilled physician to diagnose and accurately treat a patient utilizing this medium as a means to gather information. Lacking test data....... it is far more likely that he/she would not hit the bullseye a lot of the time. Taking an air transport type aircraft (737) that had an incapacitated pilot, and talking down to a landing even an experienced private license pilot by a pilot on the ground is not an easy taske and would bne very likely not to end well. It is no differnt for ceramics.
Yes.... there was a four letter word involved........ TEST.
On to the new questions................
Typically the kiln sitter is not the way to control the shutting off of the kiln at the end of the firing... although it seems to have become that to many people. It is really best as a "fail safe" device to shut off the kiln if neither the computerized controller (if there is one) nor the potter has shut off the kiln when it was suppoese to be shut off (via watching witness cones). The cone that is placed in the sitter prongs is then selected as a slightly HIGHER cone than the one to which the firing is intended to go. It prevents the kiln from "running away" too badly on the firing. It is another piece of the redundency that the kiln sitter with a firing duration timer provides.
So you should be able to soak at the end of the firing easily, because the kiln is not being shut off by the sitter.
And remember that cones do not measure temperature..... they measure heat work. What we care about is the effects on the ceramic chemistry provided by the application of heat energy. We can (within reason) get the same effects on the chemsirty by firing over a longer time to a lower temperature that we do firing over a shorter time to a higher temperature. That is indicated on the cone charts when you notice that the cone end point termpetures listed there are in columns organized by "rate of climb".
So a "soak" at a particular temperature will result in cones further melting. (It affects the ceramic chemistry the same way.... which is what cones are for.) So if you wait until cone 08 is tip to base ("down"), and then soak at whatever temperature is indicated on the pyrometer, you can expect that cone 07 will also be heading down soon. A soak should be happening before the end point cone is reached......... and should be bringing the firing TO the desired end point cone.
As to WHY someone might (effectively) decide TO soak.............
Remember, if you do a soak and you don't NEED to do that... you are simply wasting time and energy (hence, money).
Soaking can allow the temperature in the kiln to even out. Thermal lag in the various areas of density of the kiln's load will sometimes (often) result in varied heat penetration into the load. This allows the firing to become more even.
Soaking can give more time for certain chemical reactions to take place if they were not given appropriate time before that.
As to what is often known as "candling"..................
This is often a practice that is using the kiln not to "fire" the work, but as a drying unit. (Industry often uses unit that are called "driers".) The purpose is simply to make sure that the last of the water of formation has been driven off before you go above 212 F and any water present turns to steam. A tiny bit of water turns instantly to a large volume of steam... and we all know what that does if it happens within the walls of a clay object.
Another reason for possibly "candling" comes from fuel fired kilns of an older generation. The draft on a fuel fired kiln is determined to a very large extent on the temperature of the effluent exiting the exit flues at the top (for updraft) or the top of the chimney (for crossdraft of downdraft). Draft circulation on fuel kilns also has the impact of circulating the hot gase evenly throughout the kiln, thereby assuring even firing. So candling was used to help get the gases exiting the kiln hot enough to establish a draft patern that was appropriate to getting that particular kiln to fire well (as in "evenly"). On wood fueled kilns it was important to get the draft to flow well to get any primary air supply so that larger amounts of wod could be burned to advance the temperature.
So this aspect has no real application to an electric fired kiln. And it has little application to a forced air gas or oil kiln where the draft is established by mechanical means (the blower(s).
If I say "don't candle".......and your ware is wet.... you are not going to be happy. If I say don't soak, and your ware is a high carbon content clay and your electric kiln has poor ventilation system... you are not going to be happy. If I say "always candle" and your kiln does not need that..... you are wasting time and money. And so on.
When I do consulting work for kiln or ceramic technical clients, I ask more questions of them than they ask of me. It is exactly like being a doctor and trying to accurately diagnose something realatively complex. The doctor is going to recommend some testing before reaching the final diagnosis and treatment.
Hope that stuff helps.
This discussion is very relevant for me, in fact I was planning on posting a query today about soaking.
I have an "Old Lady" Paragon electric kiln, one I call Old Lady because an old lady had it sitting in her garage for years and years and it's really old. I bought it nearly two years ago and, knowing nothing about what I was doing, commenced to learn to make pottery and use the kiln. For about a year she worked just fine, then the element connectors needed to be replaced, which I did, and the bricks needed to be patched, which I did. I got a pyrometer to monitor temperature inside the kiln--a real steep learning curve! I was happy with my works. Then my ^6 glazes stopped looking pretty and I noticed the temperature inside the kiln dropped 400 degrees in the first hour after the kiln sitter tripped. Those in the forum recommended performing a soak by re-setting the kiln sitter; I found how to do this exactly in a book on electric kiln firing whose name escapes me now. It didn't give exact details, so for my last glaze load I stayed by the kiln, waited until the sitter tripped and immediately turned the kiln back on, set the temperature to medium and set the timer for 4 hours. The glazes in this load, with this test, were gorgeous. The temperature dropped 200 degrees in 4 hours, so it was essentially successful. (I think.)
My question is: Does this soak--if it is that--make sense? Is it better to leave the temp at high and shut it off at a certain period of time or could this result in overfiring? It seems like the latter is true. I know someone will say--if it worked, it worked, and continue doing it that way, but I would like some opinions from you experienced potters out there. Is 4 hours too long? I have a nice big load nearly ready to fire this Saturday.