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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.

Thank you everyone for all the replies! This is amazing. I've not found people elsewhere this helpful, you folks know your stuff. Kelly! I'm overjoyed to see another bone china piece that seems to have a touch of green in it! I was a little unsure at first, the plate you linked is possibly porcelain, and could be glazed green, but the Narumi piece has a green band around the footring where thick, but a yellow body. I did some digging and I found some 1980s bone china of theirs online with a distinct green tint that matches mine very closely. Super exciting, you must have done some serious googling. I will say green is not common at all, nothing I have that wasn't made by me is green, nor has anyone else's that I've checked. It is clearly out there though. I'm put at ease seeing it in something made professionally, it can't be a sign of fault. It must just be some arcane material interaction. It couldn't be iron, as all other bone china would have iron in similar amounts. My bone china has only slightly less iron on average than vintage English bone china (they entirely use nzk now I'm told), so I'd imagine I'd see similar results if iron were the culprit. That leads me to look at differences, I use Veegum T and don't use Cornish stone or a sub. It must be something in either of those. I've already tested real bone ash vs TCP, both giving greens, so that isn't it. My mind zeros in on the Cornish stone, I can't be sure of much else, but I can be sure that Narumi wouldn't import Cornish stone, they'd find another flux. As they produced ware with that green as far back as the 80's, whatever it is needs to be available back then. That possibly rules out Veegum T, but maybe other refined Smectites were available? As min points out those contain magnesium, that could be it, and is easy to test for! In my work, I've been playing with combinations of frits, soda spars, and silica in the 25% of the recipe that would have been Cornish stone. Min, I will absolutely test your suggestions, but you don't need to ship me any materials. That is too kind, but I share space with a long running large production studio (also where I work), odds are I can dig some vintage stuff up in there and work something out. I'll get the sub on my spring order. For Peter, yes I can confirm I've tested it in many lighting conditions. I use neodymium a bit and have lots of lights to show it off, made that test easy. Thanks everyone, I've got some serious testing to do now. I'll check back frequently!

If there's still any liquid in them, you might be able to use them but, in my experience, re-hydrating dried out acrylics doesn't work.

I recently had a house fire and many small containers of acrylic paint were subjected to severe heat but not directly burned. Will they be salvageable? Thanks Katiethepaintinglady

To give back to the thread, I just had great success adding 4% Veegum T ($$$) and 0.5% CMC gum to my LF clear and then gelled it further with a touch of epsom salts. The result is a bucket with about the worst rheology possible, unworkable by all rights. However, I dipped a couple pots through the glaze, shook them a bit, and got really good even application. It dried well without any cracking. I tested layering and that worked great too! I won't get a chance to fire for a bit, but thickness is good so I can't imagine how it could go wrong from here. Up to you if ease of application is worth the VeeGum T tax.

Just curious...why low-fire earthen ware rather than mid-fire stoneware?

I too have experienced the same issue with white clay firing yellow -ish under clear glaze. Ugh, so frustrating. While I'm not using Standard's white slip I do work with their white earthenware (STD 105). I recently discovered that same document from Standard (https://cdn.shopify.com/s/files/1/0039/8177/0841/files/105-LFW_Glaze_Rec.pdf?v=1674848426) and find it interesting. I've been using Mayco/Duncan PB001 which is on the list as compatible (crystal clear at cone 04) but it wasn't for me. That said... I did test the Spectrum 700 and was happier with the results. The clay is definitely whiter under that clear glaze. I bisque and glaze to 04.

Pack the middle the tightest. Have you tried just using the cone 08 preprogrammed firing schedule?

Test the element resistance, it's the best way to know for sure. But with 15 minutes longer and 75 firings they're probably still good. Resistance per section for 240V1P should be about 14.45 ohms.

@neilestricke23T cone 5.5, Slow glaze slow bisque Yes, we have a meter. I have not measured. Glaze firings, 15 minutes.

What model kiln is this? Serial number? What cone are you glaze firing to? What schedule do you usually use for glaze firings? Do you have a meter so you can measure the resistance of the elements? https://hotkilns.com/test-resistance-ez How much longer are the firings taking?

I have elements and TCs on hand, but I have held off changing them. You can see why from the photo. As expensive as elements are, I have hesitated. The reason they have different firings on them is because there was an issue with the top element. I had glaze on it and it burned out. So I changed just those 2 top elements. The top 2 elements have 73 firings, the bottom elements have 62 The kiln is still running, bisque firings are not extended, glaze firings are a little longer. What would you all do? Change them all out? I can't seem to flip the photo. Sorry.

Still using "SE 13 1/4 Inch Stackable Classifier Gold Prospecting Pan" for sieving glazes. I'd bought an 80 and 100 mesh. They fit a five-gallon bucket. Looks like the price has almost doubled since 2018 (I'm seeing just over $30 each now). I'm encouraging flow with my rubber gloved hand. The sieve rinses clean easily. For small/test batches, I'm still using this smaller unit, which I'd put together for screening glaze at the JC Ceramic Lab (when I was taking classes there) using 100 mesh stainless steel screen (I still have a few square feet of screen!), a plumbing collar, a section of black pipe that fits in the collar, and some glue. Almost as easy to make several, so I did, and gave the extras away... Still using US Balance 2000g (it will go a bit over 2000g before erroring out) scale (~$26, today, about the same as six years ago). I thought it a reasonable compromise between inexpensive and sufficient to the tasks. The 2000 gram limit means more than one step for some glaze ingredients.

At 800 degrees, the glaze particles have not begun to sinter, they are just a little toasty. Fix the kiln and refire.