PeterH

Don't think anybody has mentioned applying excess wash and then sponging it off to emphasise texture yet.

Do @Bill Kielb's tests first. PF is a controller display DCT 600 manual https://paragonweb.com/wp-content/uploads/IM-126-DTC-600C-DTC-600-Instructions-1.pdf My naive interpretation is that it could just be "finger trouble" Or else it requires working through a list of probable causes. See p1 To Begin, display IdLE p1 The Safety Switch p4 Controller Displays PF. PS I find a fuse resistance of 4.2ohms difficult to credit, they are designed to be near zero resistance or open circuit! Two possible explanations are: 1) The resistance is really zero but there is some in-circuit corrosion whose resistance is also being measured (cleaning contacts and measuring out-of-circuit reduces the chance of this). 2) The measurement was taken with a meter not really up to the job (especially a poorly-calibrated analogue meter on a scale intended to read much higher resistances). ... Although when I've been in this position I asked myself "is the fuse open-circuit" rather than "what is the resistance of this fuse". Not open-circuit => fuse not blown (usually).

Just to emphasise that the "height" of your final mould can more than the "height" of your cottle boards. Not least because it may be easier to create multi-part moulds this way.

That doesn't seem consistent with the figures in http://www.skutt.com/pdf/service_manual/11_4.pdf OTOH the wiring diagram https://skutt.com/images/KMT714-W_8510.pdf shows one element across the L1/N split and two elements in parallel across the L2/N split. If the socket is fed from a split-phase supply these voltages are 120V (if the socket is fed from a 3-phase supply they are 108V). If all three elements are 11.7 ohms this gives power consumptions of 3,692W & 2,990W (close to the published figures of 3,600W & 3,000W). I can find no combination of 11.4 & 5.7 ohm elements which gives comparable power consumptions.

Confused thread about the two versions of the kiln Although Mop (a UK resident) seems to be talking about 13 & 16 amp 230v versions, rather than the 208 & 240v US versions. Anyway, the UK versions have max cones of 8 & 10, which will effect the element lives when firing high. What cone do you glaze-fire at? The US versions (which both have the same element resistances but different voltage feeds) look like they have similar differences in power -- and presumably max cone rating. PS Slightly surprised to see the UK classified as 230v rather than 240v, but I was forgetting about the great non-standardisation. The voltage used throughout Europe (including the UK) has been harmonised since January 2003 at a nominal 230v 50 Hz (formerly 240V in UK, 220V in the rest of Europe) but this does not mean there has been a real change in the supply.

Minor insight in PS, the rest is just cut & paste of potentially relevant facts. Looks like DIAG is used to indicate the kiln's diagnostic tests, which include VOLT. https://skutt.com/skutt-resources/troubleshooting/diagnostic-tests/ Specification sheet https://skutt.com/pdf/service_manual/km_kiln_specs.pdf ... which seems a little economical with the truth. - Will fire with 240V or 208V power. - should never be fired on a 240V supply without first installing a full set of 240V elements. Wiring diagram (without element resistances) https://skutt.com/images/KMT714-W_8510.pdf BTW the element resistances for 240v & 208v might be the same! PS It might be interesting to use the AMPS feature in the dIAG (if fitted)? Am I right in thinking that the current resistances of the elements are given by VOLT/AMPS(1), VOLT/AMPS(2) & VOLT/AMPS(3)? http://www.skutt.com/pdf/service_manual/11_4.pdf

Pure & Simple suggest https://cdn.shopify.com/s/files/1/1130/0194/files/INSTRUCTIONS_2021.1.pdf?v=1609298598

Thread on pancake opening ...

Would adding an "inert" stain to the commercial glaze serve your purpose? I suspect stains consisting of spinel pigments would be suitably inert, although obviously check the small-print. For example Mason 6600 best black 6600 https://www.masoncolor.com/ceramic-stains/blacks/6600-best-black). reference notes https://www.masoncolor.com/reference-guide >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>^^^^ Don't know how serious the advice "Use only as a body stain" is. For example https://www.scarva.com/en/gb/Mason-Stains-By-Mason-Color-6600-Best-Black-Stain/m-2170.aspx Our range of Mason colours with over 60 ceramic stains can be used in a wide variety of cost-effective applications. All stains in this revolutionary new colour system contain NO LEAD and can be used as glaze stains ...

- If there is iron in the recipe I would strongly suspect that it's there to alter the redox chemistry. - OTOH from what I've read tin increases the solubility of metallic copper in the glaze - aiding the formation of copper colloids/nanoparticles. Suitable redox conditions are necessary but not sufficient for this. [Digitalfire points out that lead, bismuth and zinc may also act as solvents.] - Although orchestrating things to end up with suitably dispersed nanoparticles of the right size at the right time ( in the cooled glaze) remains elusive. And there may well be several different redox/solubility paths to achieve this. It's worth noticing that the formation of copper ruby glass seems far better understood/managed. Probably because controlling the redox chemistry of a covered vat of glass is far easier than maintaining the redox chemistry of a thin film of glaze in contact with a changing kiln atmosphere. There are also a lot fewer variables to play with when experimenting. Most readers stop here, long ramble follows Substituting iron for tin I'm reluctant to comment on this, but it's a fair question so here goes. - Beside it's redox properties tin can be used to increase the solubility of metallic copper, and also to act as a colloidal protector of colloidal copper. Iron provide some redox properties, but non of the colloidal-enhancing./protective ones. - Several of the recipes in https://puttgarden.com/crystal/friends/tom-turner/9-9-09/cu-red-tc/art0003.htm contain red iron oxide. Interestingly the two with the lowest tin levels contain iron. - If you try any experiments I'd start substituting atom-for-atom. Confirm with wiki, but molar masses are SnO2=150.7 & Fe2O3=159.7 so for atom-for-atom use about half the weight of red iron oxide. - Personally I might try adding iron to an existing recipe first, and see what happens. Tin seems to be involved in keeping a lot of balls in the air https://digitalfire.com/article/copper+red+glazes In terms of composition, the glaze needs to be able to support the solution of Cu. To achieve this it needs to have things in it that are friendly to the presence of metal. The best of these is PbO - I can hear the gasps of horror now. Yes, that Godzilla of the Elements. Bismuth is another good option in some glazes, Zn helps and there is, of course, tin (Sn). Sn does a couple things. First it improves the solubility of Cu. Metals, per se, aren't really very soluble in glaze and if you can't get the metal dissolved, it can't very well be precipitated in any organized fashion. Second, on cooling, Cu tends to attract Sn atoms from the glaze. These atoms sort of "coat" the crystals as they are developed and thus serves to control their size by limiting the attachment of further Cu atoms to the crystal. This behavior is that of a protective colloid and it is of great advantage. Because if the crystals get big, the glaze turns "livery" looking, and the doughnut remains elusive. Third, to the extent that Sn has limited solubility in SiO2 or B2O3 based glassy material, it probably also serves to provide nuclei on which the coloring crystals can grow. Tin oxide is added to all practical non-lead Cu red glazes in amount way beyond what's necessary to promote good solution of Cu in the glaze - many compositions contain up to 4-wt%. Of course, if there's too much tin it doesn't all dissolve -- causing opacity. This may or may not be desirable. Tin is volatile at high temperatures and a lot of it leaves the very thin glaze film by evaporation. Compensating this evaporation is important to how much tin will remain dissolved in the glaze. This explains the large amounts of SnO2 in many reported glaze compositions. Some kilns have turbulent atmospheres and a larger amount of evaporation would be anticipated in these circumstances. In glassmaking, if you melt in a covered pot, in which evaporation is not an issue (in most cases), the amounts of SnO2 required seldom exceed 2 wt%. If you use too little Sn to promote the solution, Cu will precipitate on the spot with dreadful results. This is one of the reasons that application of the glaze is so important and why really thin films often fail to develop a nice red - when red color forms at all in a tin depleted glaze, it often has the color of liver instead of a crisp red. The amount of Cu necessary to develop a good red depends on how much of it can be dissolved. This depends on how much the glaze would dissolve on its own and how much this is improved by the presence of Sn. Many pottery glazes contain what I feel is a lot of Cu-oxide in the batch, but that's just an opinion. The best reds always contain the least amount of Cu. Reduction is the critical step in producing a nice Cu red. Note that some of the tin in the glaze can be lost by evaporation (especially high-fire & gas?) . By reducing evaporation you may be able to reduce the tin in the recipe without needing to substitute. Maybe some of the ideas here (to reduce the loss of copper) might also reduce the loss of tin? https://puttgarden.com/crystal/friends/tom-turner/9-9-09/cu-red-tc/art0003.htm One must be able to apply a red glaze fairly thickly so it can make it through the higher fire reduction periods without dissipating its copper content. There are all sorts of simple methods one can use to ease this problem: Brush on iron oxide over the glaze. This will help seal the surface at high temperature. Brush a thin solution of copper slip under the glaze. This will produce a barrier to hold in the copper. Fire the pot in a sagger that has copper carbonate brushed on the inside of it. This works to keep the copper gasses flashing back on the pot. Put a clear, slightly lower-firing glaze over the base red glaze. This acts in manner similar to the iron oxide but allows more color to come through. Add a small amount of silicon carbide powder to the glaze. This creates an internal reduction that dissipates less rapidly.

Nice discussion on copper/tin interactions in Copper Red Glazes https://digitalfire.com/article/copper+red+glazes Well worth reading the whole page, but the highlight is perhaps Sn does a couple things. First it improves the solubility of Cu. Metals, per se, aren't really very soluble in glaze and if you can't get the metal dissolved, it can't very well be precipitated in any organized fashion. Second, on cooling, Cu tends to attract Sn atoms from the glaze. These atoms sort of "coat" the crystals as they are developed and thus serves to control their size by limiting the attachment of further Cu atoms to the crystal. This behavior is that of a protective colloid and it is of great advantage. Because if the crystals get big, the glaze turns "livery" looking, and the doughnut remains elusive. Third, to the extent that Sn has limited solubility in SiO2 or B2O3 based glassy material, it probably also serves to provide nuclei on which the coloring crystals can grow. Tin oxide is added to all practical non-lead Cu red glazes in amount way beyond what's necessary to promote good solution of Cu in the glaze - many compositions contain up to 4-wt%. Of course, if there's too much tin it doesn't all dissolve -- causing opacity. This may or may not be desirable. Also of possible interest The Dual Mechanisms of Tin Oxide in Copper Red Glazes https://glazy.org/posts/168150

Only hand-waving, but I expect the importance of tin (and iron) in some copper glazes is because all three elements have variable valencies; and in the right circumstances can help redox reactions move copper from Cu(II) to Cu(I) or even Cu(0) -- and/or buffer it against oxidation once it's in the desired state. There is also Weyl's point that the presence of tin increases the solubility of metallic copper in a glass (or glaze), which can be important in obtaining colloidal copper particles. Woldemar A. Weyl Coloured Glasses has some interesting thoughts on the colouring mechanisms in glasses. Not cheap, but if you can borrow it on an interlibrary loan ...

I see that you are in Iran. Can you give us some idea of the materials you already have, and those you can get from your suppliers? Here are two handouts from a reputable source, using ingredients readily available in the USA. STA Decorating Slip https://www.vincepitelka.com/wp-content/uploads/2016/03/STA-Decorating-Slip.pdf Table and Explanation of Slip and Engobe Composition https://www.vincepitelka.com/wp-content/uploads/2016/03/Slip-Recipe-Chart.pd @YanaAsh Can you comment on the availability of suitable products/suppliers in Iran?

Change this search to your location & currency. Cheapest 2nd hand here is £232! https://tinyurl.com/2p4k2jst Does your country have an inter-loan library system? I've no idea if the sign-up ebook services or are real or scam., but a google for ash glazes phil rogers pdf turns up http://infinity.wecabrio.com/080198243X-ash-glazes.pdf ... and a thesis by somebody else on glazy https://wiki.glazy.org/uploads/default/original/1X/085b890dabdd507a348fdcc09e4247b954029145.pdf Posts for wood ash on glazy at https://glazy.org/?keywords=wood ash ... including a Stull Chart

I doubt it, but am not in a position to know. However you would only be using it to seal the unglazed edge of the collar, which would presumably not be in contact with the soil. Minimising any opportunity to leach.

Perhaps relevant: Outdoor Weather Resistant Ceramics https://digitalfire.com/article/outdoor+weather+resistant+ceramics This is a common sealer available at a hardware store. I have dipped the terra cotta tile and it has dried. The surface of the dipped portion is smoother and has a slight sheen. That is the price paid for sealing the matrix against freeze-thaw spalling.

You can find your kilns part number from the info on https://paragonweb.com/support/kiln-wiring-diagrams/ If you then enter the p/n into the pages search field it will give you its kiln wiring diagram. This should show you the "as new" resistances of your elements. PS If you post your p/n it will help the experts customise their answers.

Sorry, I meant there was unlikely to be a major flux-based "chromatic influence" for Celedons towards the golden metallic effect the paper was seeking. In this project, a kind of glaze that resembles metal glaze with golden color, simple color and no obvious luster

Yes, I intended the picture as an example of the effects of an applied leaf, and a mulberry leaf in particular. I was suggesting that the paper I was discussing seemed to start by looking at the traditional leaf-based way of obtaining an image and then thought: hey what if you used leaf-ash (or its chemical equivalent) as a "local surface additive". And the paper expands on the idea (I thought overglaze was less of a mouthful than "local surface additive"). Thanks for the thoughtful contribution and very interesting reference on colouring mechanisms. PS I find it interesting that the paper applied to technique to Celedons. Which I suspect would be less likely to be "chromatically influenced" by things like local flux changes than Tenmokos.

An interesting spin-off? I welcome others interpretation of this paper (pity it doesn't have a pictures) Research on the New Woodleaf Glaze in Celadon https://www.scitepress.org/Papers/2019/85615/85615.pdf The image on a good leaf bowl is notable both for its fidelity and its colour. https://www.yuyinghuang.com/shop/mulberry-leaf-tenmoku-teabowl This paper thinks of the leaf as a way of applying an over-glaze image to the pot. It starts by analysing the mulberry leaf ash as it is heated, and comes up with a glaze formula: Any thoughts on the colouring mechanism? And is it a property of the overglaze alone, or a reaction with the base-glaze? It then considers the use of this overglaze which it uses with a celedon base-glaze. Combine with celadon's mud glaze to make no less than 6 sets of test pieces, (I'm not sure if it is applied it as an overglaze, or mixed it with the celedon.) ... and then looks at the effect of firing temperature. Pity there is no pictures. PS It would be interesting to know the analysis of the ash of other leaves traditionally used for leaf bowls.

222 page thesis TRANSFORMATION OF SIX LEAVES GLAZE TO CONTEMPORARY CERAMIC BASES ON THE TAOISM CHARACTERISTICS https://tinyurl.com/4a48pyky In the research process, 768 glaze recipes have been tried. A total of more than 600 kilns have been fired, and more than 20,000 pieces of products have been fired. In the early stages there were a high probability of failures. However, the rate of finished products finally increased from 2% to 80%

木の葉天目茶碗 (Konoha Tenmoku bowl) https://www.teaforum.org/viewtopic.php?t=1863 http://www.tokorozawaclub.com/HP/okachan/konohatenmokutyawan.htm Seems to be some how-to pages (scroll past the first tiny ones) Sample pix I now appreciate John Britt's comment about removing them with a magnet better.

No process info. Young Chinese girls revive, innovate 1,200-year-old porcelain leaf cup making techniques http://en.people.cn/n3/2021/0113/c90000-9808774.html

One line of thought The quest for the illusive leaf bowl: John Britt describes his search for an ancient technique. https://tinyurl.com/7bfmn6fc ... with the intriguing content Then, while on Facebook, a Japanese woman named Mia Ishiguro (no relation to Munemaro) noticed that I was researching the leaf bowl and having trouble, so she sent me the symbols for 'leaf bowl' in Japanese. ([TEXT NOT REPRODUCIBLE IN ASCII]) I copied and pasted these symbols into Google and found a lot of information, unfortunately written in Japanese, which I cannot read but, being a visual learner, I decided to click 'Images' and voila--thousands of images of the leaf bowl instantly appeared. I started to click the links and many connected to museums and historic books, while others led to blogs of people who, like me, wanted to figure it out. Several others led to newspaper articles allegedly describing the technique. I was excited, saved these articles and printed them out. Although I could not read them, I could deduce what was being done by the pictures. Today Google will translate text for you but not images and some of these were photos of newspaper articles. Nevertheless, this gave me some excellent techniques to try. Google translate gave leaf-bowl => リーフボウル Which sadly gives lots of images of leaf-shaped bowls! Printer friendly version at https://www.thefreelibrary.com/_/print/PrintArticle.aspx?id=372884215 The article appeared in print (no idea about the Japanese symbol) Ceramics Technical ISSN:1324-4175 Issue:38 Page Range:84-88 First Page:84 Last Page:88 John also sold an ebook containing this and other articles, don't know if it's still available. Not here, but some photos https://tinyurl.com/mvmnu3xf Guarded praise from J Baymore ... PS An historic example at https://www.britishmuseum.org/collection/object/A_1973-0726-279 PS Google translate into Chinese (traditional) gave leaf bowl => 葉碗 A google search for images then gave a few hits, the first of which was https://m.fei123.com/10000/4218.shtml

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