PeterH

Has anybody any idea why there would be barium carbonate in a black glaze? ... on second thought maybe it's to give a velum matt finish. If the barium isn't significantly effecting the colour, and the glaze is already matt, would this minimise the chances of a vinegar test showing anything (even if barium was being leached)?

I vaguely remember Ian Gregory (of fibre kiln fame) making a similar comment during a demonstration -- about being able to fire a kiln-full of freshly thrown pots without trouble. He then immediately said that with somewhat dryer pots this didn't work. The impression I got that there was a brief sweet-spot where this was possible (and then only for a kiln-full of such pots), not that the state of dampness wasn't important. I've no coherent theory to explain/understand this claim. Although its possible that some sort of wicking process draws the water to the surface as the pot dries, and the large number of wet pots in the kiln limits the temperature ramp while there is still surface water to evaporate. Surface drying before firing could prevent such wicking of water to the surface during firing.

This earlier post by @Jeff Longtin may be of interest

Perhaps of mild interest, despite cryptic translation. https://patents.google.com/patent/CN1055278C/en Method for making colour glaze natural leaf figure ceramic product Abstract The present invention discloses a method for making color glaze natural leaf pattern ceramics. Natural leaves or plant leaves are stuck to a blank coated with base glaze after particularly treated, and a layer of surface glaze is coated on the blank. Then, the blank is put in a kiln to be burned to obtain a ceramic finished product. The present invention uses ceramics as a carrier, and natural leaf patterns are burned on the ceramics. The leaf patterns are clear, natural and vivid and have beauty sense and very high appreciation and collection value. The present invention has no particular requirements for conditions of the base glaze, the blank, combusting atmospheres, etc. and has the advantages of simple preparation process and easy operation.

Hang on ... it's still out there. Usable link below A google for TRANSFORMATION_OF_SIX_LEAVES_GLAZE_TO_CONTEMPORARY_CERAMIC_BASES_ON_THE_TAOISM_CHARACTERISTICS filetype:pdf gets me to an Resource not found error page at http://www.sure.su.ac.th/xmlui/bitstream/handle/123456789/20993/DR_FENG_Shanxin.pdf?sequence=1&isAllowed=y Clicking on Go to SURE home get me to the sites home page at http://www.sure.su.ac.th/xmlui/ From there a search for TRANSFORMATION OF SIX LEAVES GLAZE gets me to the pdf at http://www.sure.su.ac.th/xmlui/bitstream/handle/123456789/24111/DR_FENG_Shanxin.pdf?sequence=-1&isAllowed=y I give the search details as it's possible that you may find other items on the site of interest. PS ... and an alternative URL, possibly to the same instance of the file : http://ithesis-ir.su.ac.th/dspace/bitstream/123456789/2977/1/60155902.pdf

Setter is a name for types of kiln furniture which offer some protection against slumping/distortion. https://www.earthwaterfire.com/products/setters/ Ceramic Setters are special items of kiln furniture which, in the ceramic tableware industry, are shaped (generally on their upper surface) to conform with the undersurface of plates and dishes and which serve to support ware and maintain its shape in the kiln during Setters are especially important when firing bone china. https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/Tempting-Transparency# In cases where the bisque firing is much higher than the glaze firing, as is normally when working with the case with bone china (between 2246–2300°F (1230–1260°C)), it’s essential that the clay ware receives the maximum support during the firing process, particularly as most of the movement occurs when the kiln reaches its highest temperature. Due to the high distortion factor encountered with bone china, if the shape is to be controlled, any open form requires a setter of some kind. If the form is circular at the top, it can be placed upside-down on a refractory clay ring, or setter, with an alumina wash to prevent sticking in the firing. If the form is irregular at the top edge an individual setter needs to be made. In simple terms, this is an item that resembles a lid and is cast separately (the preferred making method for bone china). Its function is to contain the top edge, or rim, of a form during firing (figure 10) and is discarded afterward. If the piece has been successfully fired with no distortion, the ware can be glazed and fired at a lower temperature of 1832–1976°F (1000–1080°C), if necessary.

http://www.vincepitelka.com/handoutsinformation /https://www.vincepitelka.com/wp-content/uploads/2019/02/Low-Pressure-Gas-Orifice-Chart.pdf http://www.wardburner.com/

Can somebody point me to an Orton chart which shows the temps for small and self-supporting cones when fired at the same rate? PS The first chart I found gives the (different) cone temps for small cones at a significantly higher firing rate for the small cones. ... this page, while referencing the same Orton charts, implies that small and self-supporting cones operate at the same temps (when heated at the same rate). https://nmclay.com/informational-pages/orton-cone-chart-in-centegrade ... but gives no Orton reference for this

Do you still have access to the clay and wheel at college? If so might be worth trying home clay wedged at home on the college wheel, and vice versa. It might at least remove some variables. ... and carefully consider any differences in body/arms/wheel/chair relationships in the two situations.

Pedantically, as P=V^2/R wouldn't a change from 12v to 16.5v to increase the power by a factor of (16.5/12)^2 = 1.89? I've no idea how much this would change the operational life of the relay though.

Do you mean like this? 3D Printing a Mold for a Slipcasting Mold https://www.instructables.com/3D-Printing-a-Mold-for-a-Mold/ Looks like a viable way of making individual parts of a multi-part mould.

Any help? https://davidneat.wordpress.com/tag/preparing-styrofoam-for-silicone-rubber-covering/

John Britt's summary of kiln wash recipes, with some thoughtful explanations. The Many Layers of Kiln Wash: How to Find the Best Kiln Wash for Your Firing Temperature and Methods https://tinyurl.com/3695jpf2 ... and a deflocculated variant of one of them Self-Leveling Kiln Wash https://jeffcampana.com/self-leveling-kiln-wash/ and https://glazy.org/recipes/42065 PS From the comments section of the self-leveling kiln wash paper John Britt says: October 11, 2010 at 11:21 am Nice Jeff, I believe that is called Lee’s Incredible Kiln Wash” $25.00 a gallon on Etsy, ... although contrast with @Bill Kielb's earlier comment Folks have “speculated” that Lees is zircon based. I am not sure anyone knows it’s actual composition

Another video of a firing, looks like the same pots after glazing and after firing

Eleaceramics seems to be Elea Lelimouzin, ceramicist in Bordeaux, web page https://elea-lelimouzin.com/ Video of a glaze firing. If they are the same pots before & after glazing firing I'm confused.

Suggesting/pointing-out that the talc wouldn't be acting as a flux is one thing. Suggesting that this means that a 50% talc body cannot have a high thermal expansion seems -- on Hansen's evidence -- just plain wrong. If it does have a high thermal expansion then claims that this cannot assist glaze fit seem misguided. Of course, people may have been have been using erroneous arguments to explain why the thermal expansion was high. But disproving those arguments doesn't influence whether or not it actually is high.

Pure speculation, but uniformity of the glaze might indicate the use of a stain ... If the colour was due to an "inert" stain and the embedding glaze matrix did leach: what would leaching tests show? Presumably as the glaze matrix is leached stain particles would become free. But unless the stain itself was attacked by the leaching agent the offending elements would not go into solution, and would not be picked up by "wet" chemical tests on the liquid. Doubt that stain particles have been shown to be safe to ingest. PS The mugs and a Mason stain

You may find this thread by a beta-tester of the (discontinued?) Bartlett Genesis LT-3140 of interest https://tinyurl.com/jtcjby88

Was Max Katz claiming that the talc doesn't increase the thermal expansion (and hence improve glaze fit), if so I'm confused. In https://digitalfire.com/article/low+fire+white+talc+casting+body+recipe

Just for reference https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/In-the-Studio-Make-Your-Own-Kiln-Setters BTW "Start with a 4545-gram batch of the Mullite Setters dry mix (recipe on page 11) and add it to 32 ounces of water" makes more sense when you realise 4545g is close to 10 lb.

Sorry I have no experience with ceramic printers. But if you have only been in contact with enduring images so far sending the printer back to them may not be the optimum move ... Here is the official Ricoh policy on servicing Enduring Images ceramic printers: “The full Ricoh warranty can be found on the Ricoh web site at www.ricoh-usa.com. In summary, Ricoh printers include a standard one year Ricoh warranty including parts and labor. There are 2 exceptions. The Photoconductor Units (PCUs) and the Intermediate Transfer Unit (ITU) are limited to 90 days. For Ricoh printers sold by Enduring Images, the standard Ricoh warranty applies except that there is no warranty at all on the PCUs and ITU. So, within the first year of ownership, Enduring Images customers can expect full warranty repairs on the printer except for any failure of the PCUs and ITU. Those devices will be replaced at the customers expense, or covered by Enduring Images, but there is no Ricoh Warranty of any kind on those components in an Enduring Images ceramic printing system. After the expiration of the one year warranty period, any Ricoh service office or 3rd party Ricoh Authorized Service Provider can repair Enduring Images printers on a T&M basis (at standard rates). Because they are not modified in any way (except the toner) all standard Ricoh repair procedures are applicable.” Sounds simple. The underlying premise is that any part of the printer that contacts ceramic toner cannot be warranted because the result of that contact has not been studied and is unpredictable. For reference, the components that contact the toner are: toner cylinders, toner feed system, photoconductor units (PCUs), image transfer unit (ITU), and fuser assembly. The PCUs and the ITU only get a 90 day warranty from Ricoh, so they are essentially exempt from Ricoh’s warranty too. This is because statistically those are the components that break. But there are some techs and field service offices that will simply walk away from making any repairs if they learn ceramic toner and not Ricoh toner is in the device. Again, rare but call us if this happens. You can minimize any delay in repair if you have an authorized 3rd party service provider near you. They don’t care so much about policy but want to provide good service so that you call them next time and not Ricoh. Find one. They can be your best friend at the worst time. Problems occur when your Ricoh tech has never heard of Enduring Images. If you can avoid discussing ceramic toner then do so, because this will prevent confusion on the part of the service tech. If it never comes up, the service tech will fix the printer like any printer. But if it does come up, and it will if the part is covered in ceramic pigment, you should be prepared to give the tech the statement above. If they have any questions about it have them call us. It is rare that a service tech will care about the toner in the printer unless it is in contact with the component suspected of causing the problem. If the tech deems that the toner is causing the problem, then they can charge for repairs that otherwise would be covered by the one year warranty. After the one year, it no longer matters since all repairs are T&M and why would they care. T&M work is a good gig. So this issue is primarily relevant during the warranty period. Again, call us if it surfaces after the warranty and a tech decides they don’t want to repair a ceramic printer. This is contrary to policy but does happen, and it can take several weeks to resolve the misunderstanding. We generally cover all of this during training, but it looks like we have missed it for a number of customers. We’ll do better in the future and will make sure it is part of training videos. I hope this blog helps everyone else.

@felix3232 My interpretation of your problem is that the decals aren't getting printed right, rather than aren't firing well. Can you confirm this? It may be simpler/more-local than that. Enduring Image printers seem to be re-badged Ricoh printers. The Enduring Image help-desk seems to only handle problems specific to the ceramic pigments used (e.g. firing advice?). They recommend/will-pass-you-over-to the Rocoh help-desk for printer-related support. Which seems to be what the OP might need. And surely Ricoh will have more locally based support staff (if their help-desk cannot resolve the issue). See Preventive or Reactive Ceramic Printer Maintenance? – Part 2 in https://www.ceramicprinting.com/blog/

Stumbled across this, which seems to confirm the point, and offer a mitigation of sorts: to make it into a casting slip add 0.4% Dispex; to attempt a plastic body add 3% bentonite: I have used real bone ash and have not had the smell but I choose synthetic bone ash for it's chemical consistency batch to batch [my emphasis]

@oldlady+ Not saying it's your problem, but damage/misalignment during transit can result in hard to diagnose problems. As I found out with my last (non ceramic) laser printer purchase. PS Eventually found the solution in user feedback on an amazon page of all places. You may find it interesting/amusing. look for Unstoppable Paper Jam notification on first run!!!! >>>>Here is the Solution<<<< in https://www.amazon.co.uk/Xerox-6510-DNI-Phaser/product-reviews/B01N012SZM

Can you say where in the process you are having problems? Digital ceramic print and decal process https://www.facebook.com/watch/?v=455272361928046