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When we produce a ceramic material that allows "light" to pass through that material we are working with a "glass" even though us potters call the material a clay body or a glaze. Todays "Ceramic-Tech-Today" article: Colored glass: From alchemy to empirical chemical design https://ceramics.org/ceramic-tech-today/education/colored-glass-from-alchemy-to-empirical-chemical-design/ has some useful information and background that might help determining why the bone-china pots show a color when seen in a light source. Remember that the source of the "light" is also an important variable. LT

It's my zero3 fritware clay, kiln is just a 40 litre rust bucket. I would go with the cone program as it may dynamically alter the firing depending on how it keeps up with the rate of climb. Do skutt controllers do that?

How fast did you fire it? Is it still sitting on the garage floor, if the floor is concrete you could have a uneven firing. The concrete is cold and will keep the bottom of the kiln colder. I understand that this is a small kiln, small kilns have to be set up correctly. I had one in front of a window but had to keep the window closed. It could really slow the firing and cool it down to fast. Small kilns already have a problem with fast cooling. Denice

After looking at the manual posted in the other thread this controller seems a bit weird. T1 is the time taken to get to the NEXT temperature not the C1 temperature. That seems backwards to any controller I have programmed. C1 0020c, T1 0030m C2 0100c, T2 0030m C3 0100c, T3 0600m C4 1140c T4 0100m C5 1240c T5 0000m C6 0020c That should go from room temp to 100c in 30min and hold at 100c for 30min. Then it takes 10 hours to get to 1140c (you could speed that part up) and then up to 1240c in 100m (60c/h)

Are you bisque firing first?

An image of the piece, err, pieces could help - character of the break, how thick/thin the ware, etc. What clay(s) are you using? About how long does it take to achieve 1240C? From peak, how long does it take to cool to room temperature?

It's not about temperature, it's about heatwork, which is what cones measure. Setting it at 950C doesn't necessarily mean cone 08. It depends on the rate of climb of the final 100C degrees. If it's not hitting the cone, then it could be due to the rate of the final ramp, or simply that the system needs to be calibrated. You can do a thermocouple offset which will affect all temperatures, or a cone offset to change the final temp of a specific cone. Using the pre-programmed firing schedule (I'd use Medium speed) will give you a better idea of how accurately the system is firing compared to a custom schedule.

Thanks for your reply. Not having any problems with the pots but rather feel that its not achieving the desired bisque of 950'C - trying to keep everything consistent so I know how the glazes will behave when applying and during the firing

Thanks for your message. I am going to try the preloaded cone 08 bisque firing next.

Thanks Neil, this was my next thing to try

That is a pretty low bisque...250°c/hr ìs very aggressive, what type of kiln is it? What clay body? I thought cone017 was for enamel work..

This is my first time firing my mug in a kiln (I use Mid fire clay) I used these segment: C1 (160c) 60min C2 (500c) skip C3 ( 1240c) 20 min C4 (room temperature) Each time I use my kiln my mug breaks Do you have any advice?

I tried firing it today at 1240c but my mug broke I put the Kiln in my garage and it is on a ceramic floor

I make terra sig regularly with my local clay and follow something similar to @Magnolia Mud Research’s post. I don’t go to great lengths to extract any remaining “finest particles” from the dregs. I played with that a bit but found it was counterproductive. Letting it slake a few hours then mixing it really well gets the all good stuff in suspension. I’m sure this is derived from Vince Pitelka or maybe Pete Pinnell, but it’s what I go with: 1 quart water to 1 pound of clay. 2.5 grams deflocculant per pound of clay. My deflocculant is half soda ash/half sodium silicate.

I came to the conclusion that low fire materials just didn't work for me for items needing to hold liquid..especially over time, and if given/sold to other people. It meant spending a fair amount of time (and a definate loss of money) learning how to make the chemistry/glaze ingredients/porosity etc. all working in conjunction. Mid-fire (or high) fire claybodies and glazes were way more likely to result in the desired maturity & glaze fit. I used low fire more for decorative ware that is not subject to freezing temps, no oven/microwave/grill, no liquids or wet food (like a tray for pretzels is OK) , or not something that will get lots of handling (depending on the object and it's purpose). ALso did a fair amount of reading, taking a course/class (today it is videos), to learn the basics before spending on trail & error.

I'm voting iron as well. I think that also accounts for the pinkish tint in low fire bisque pieces. If we were able to have a slab that thick of our clear glazes we would also see it to varying degrees. Window glass is also green for that reason. It look pretty darn clear when we look through it, but if you put some paint on it you'll see just how much color it really has. They make super clear glass, of course, but it's expensive. If I remember correctly they call it Water White glass. Standard plate glass and such is quite green. I worked for a glass shop for a few years after grad school, and we would occasionally have to replace opaque colored glass panels on buildings that were no longer available from the original supplier, so we just had to paint the backsides. Getting an accurate color match was nearly impossible due to the tinting effect of the green. You couldn't just have the paint color matched to the old panel.

I have a sieve that fits a 5 gal bucket, I bought it about 40 years ago. A few years ago the screen started break along the edges, so I went to the supply store and the same screen had a flimsy plastic body on it. My old screen has a heavy plastic body, my husband sealed the screen in with a waterproof adhesive. It isn't very pretty but it works and I have a really small sieve for test glazes. Denice

It's rate to just above cone 6, which means it'll only get to cone 6 maybe 50 times max before the elements need to be changed. Probably a lot less than that given the quality of the elements they are likely using. So to get any sort of real life from the elements you'll probably want to limit this to cone 2 at the most. Really we consider cone 6 kilns to be best suited for low fire work. I would definitely check to see if you can even get replacement elements for it. It appears to be on angle iron legs, but they're not very tall. Most kilns have 8" legs, so this kiln is on the short side and it should definitely need to be placed on something fireproof. If it were mine, I wold put it higher up on some bricks to give more air flow under it, with a fireproof floor below.

@neilestrick Could you comment on a couple of points. - 1) The kiln is rated at a maximum temperature of 1,240°C/2,264°F. What is a sensible firing temperature to give reasonable element lifetimes? 2) Fire safety. The manual states: Please only put this kiln on a heat-resistant worktop such as a metal stand, stones or ceramic tiles. Please note that the worktop should be very stable and be able to hold up to 30 kg of weight in total, for your safety. A photo in this advert shows the use of short legs/bricks. https://www.amazon.co.uk/Top-Loaded-programmable-Pottery-Projects-Beginners/dp/B0BZ53RXKM I assume that anything like this should be on a very fireproof/heat-resistant surface. PS @Moza Where are you intending to place the kiln while firing?

The studio that I am looking into that could possibly fire pottery for me in my town only does low fire clays and glazes. There aren't a lot of options in my town for firing pottery so looking into all my options.

Is it frustrating because it is causing problems or just because you would like the cones to read the same numbers? If it's the second I wouldn't worry about it. Neither of those schedules you have posted are aggressive. For me 100c per hour is slow, 200c fast and 250c is aggressive. I bisque to cone 016/017 (that's a guess, I have never put a cone in a bisque kiln) in 4 hours doing 20 min to 100c, hold for 20 min, then ramp at 250c an hour up to 800c and hold for 20 min. You can see the kiln drop to under 250c an hour while it struggles from 500-600c as chemical water is lost but it catches back up to 250c and hour after that.

I use a talisman at work, and while it’s great for 10 gallon batches of glaze, it would be wildly impractical in my home studio. The cleanup of the brushes is a pain. I have a smaller sieve that sits in a 5 gallon pail at home, and I use a large round sash brush to push the glaze through. It works pretty fast and cleans up very easily.

your kiln manufacturer has a long history of getting the best out of it's kilns and providing simple controls for users. why do you think your program is necessary and better than theirs? and what is special about cone 09? yours is the first post to mention it in all the years i have read almost every post. are you glazing some special way that requires your bisque so soft? once you fix the loading as suggested, just try what Neil, who is a kiln specialist and dealer, suggests.

Hi Brian_Ire, welcome to the Forum! We did a pit firing in Wheel I and Wheel II classes, no ferric chloride was used - just pit fire with some smelly biscuits added to the fire*. The wares came out interesting black, orange, yellow, and baked brown colors... This article has a long paragraph on ferric chloride safety, and another paragraph on Raku safety: Natured Inspired Firing (ceramicartsnetwork.org) Check back, perhaps others with ferric chloride experience will respond... *horses having passed since the last high tide!

Hi All hope all goes well. I am beginner potter and am mad to try out a small pit firing. I have made up some terra sig and have it bisque fired on some pieces and it seems to have worked. I have also gathered some natural materials to try add to the surface in a saggar to see what colours I can get from them. My question is re ferric chloride. I am seeing that mentioned a lot as used in firings. Do you have to add ferric chloride to the surface, when doing a pit firing, or will you still get colours on the terra sig piece without it? Thanks inadvance.