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We get asked a lot about how to fire the Olympic Torchbearer kilns. The information provided here was taken from the Clayart forum. Thank you to everyone who participates in Clayart for their help in providing this information.
I fire to cone 9-10 and (the temperatures) are almost identical top /bottom with only a few degrees difference through most of the firings. I fire smaller/larger wheel thrown, slab built rectangle and combo-built ovals up to about 22" max.
One comment first. You need a dual pyrometer setup. I got a fluke and use the 12" probes with the ceramic protection sleeves. These fit snug in the peep holes and keep the probes from sagging. I don't think it's a fire-able kiln with any success without the dual pyro setup.
I use one probe in top peep and one in bottom. I set a 7,8,9,10 self supporting cone set on a strip of clay just at the end of the probe inside about 9-10". At that distance you can see them good later. I use TWO flames spreaders on two of the four ports. I use a two inch post on each side of the port with a 5" post laying across them and up against the wall. This gives a tiny space against wall but directs most flame out. The other two ports are not tampered with. Bottom shelf is a tad more than 4" above floor ( 1/2" above spreader arrangement 2" post with side-turned post which gives 1 1/2" more height = 3 1/2"). I use two cone six half shelves on floor with 3 1/2" posts supporting the first shelf. Shelves are spaced about 1" apart and usually staggered 90 degrees, although often I can't get that stagger or 1" space depending on sizes of pots I'm doing and it never seemed to make any difference., But, DON'T push them over to touch sides as some might tell you. Touching together ok, but blocking flames up side not helpful!The two biggest keys I found were
Use a baffle shelf at 1 1/2" from inside of top vent. I use an old 1/2 shelf from it that I ruined, or you could use a smaller round/hex shelf if you desire. My ruined 1/2 shelf works fine, but the 1 1/2" setting I found was kind of important. It just doesn't work firing without it and if too close or too far it won't fire even either. I then use a couple small cone six test kiln shelves for adjusting port air outside on top. They aren't really even used until late in firing.
The air adjustments on burners are VERRRYYYY important. Once set, never adjust. Recommendations from the start had me setting them at 1/2" and I had NO reduction whatever I did, blew it's self out when tried, very noisy. Michael suggested 1/4" and THAT was the ticket. I couldn't believe the change. Quiet and reduction achievable. I couldn't believe it.
Now, I fire pretty slow since I have lots of seams in some of my pots and some good sized. Here's how I fire.
I get up about 6am and start pilot to warm up kiln. Just the pilot and it warms up a couple hours to about 180-200 degrees before I turn on a low burner flame. I never go over 250/hr. NEVER. Slow, but I have nothing ruined. I fire until about 2AMish usually. I'd rather fire longer than throw out ruined stuff!
I watch pyrometers until about cone 7 then remove them and use peeps to see cones, in fact, very often I can see top cone pack down through top vent port if my baffle and cone pack position allow me to do it that firing. My middle two ports are always plugged (something I didn't do at first).
Now with the air adjustments turned way down on burners I can now adjust reduction when I want easily with top small shelves across the port and it doesn't blow its self out like it used to. In fact, next firing I'm going to tighten the air adjustments even a little more than the 1/4", maybe one more rotation on threads.
Cones are always easier to see at the top (especially if I can look down inside) and any temp difference in top to bottom is usually with a hotter bottom now, but, cones drop almost identical, and a few times when I just couldn't make out the cones at bottom I used top ones alone and firing was identical. BTW, I use #5 darkness welding goggles I got at a safety store for about $8. They work nicer and more comfortable than the old welding mask I used to use at first. You can also get several kinds of Kevlar gloves and stainless steel thread gloves at these stores if you need them for anything, like wood carving.
I'm satisfied with firings now. I should say that ALL I MAKE are bonsai pots and don't have any fancy glazes that require tricky treatments so I'm not hampered by that, but now I am getting nicer reduction effects on my clays that I need to darken up some. I use quite a few different clays, probably a dozen, and lots of iron, so that in it's self is different than most people choices of only one or two clays.
To reiterate, the three most important things are, flame spreaders, top baffle and air plate adjustment.