PeterH
-
Posts
1,588 -
Joined
-
Last visited
Content Type
Profiles
Events
Forums
Blogs
Gallery
Posts posted by PeterH
-
-
I stumbled across this great posting giving a flavour of the many interactions in a glaze.
-
20 hours ago, kinosfronimos said:
So I've done a Google search, and also a search of this forum, for a list of 'molecular' metal oxides that can be used in glazes.
16 hours ago, kinosfronimos said:(I may have access to a university lab, hence my question)
Best to avoid mentioning 'molecular' metal oxides when talking to chemists, as metal oxides don't form molecules.
PS
Don't think that the details need worry you at the moment, but feel obliged to give a few refs.
Molecules are formed by covalently bonded atoms. Metal oxides form 'ionic crystals'.
https://en.wikipedia.org/wiki/Ionic_crystal
https://en.wikipedia.org/wiki/Covalent_bond
https://en.wikipedia.org/wiki/Ionic_bondingMost glazes are glasses, and the structure becomes both more complex and more random.
-
41 minutes ago, Hyn Patty said:
Have you actually recycled pottery plaster molds in this way, Ann? Or anyone else here? With as difficult and as costly as it can be to get plaster right now, and keeping it out of our landfills, it might be worth trying. But would be nice to hear someone chime in who has actually done it and found it still good quality.
I'm inclined to doubt it, especially for high-quality/fine-detail work like yours.
However these articles suggest that it is possible.
https://www.wikihow.com/Recycle-Plaster-of-Paris
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7276351/ -
+1
Chemical suppliers often sell very pure chemicals. Better to start with pottery suppliers who will supply pure-enough chemicals at significantly lower prices.
You might also want to look at "oxide washes".
Eye candy
https://www.pinterest.co.uk/tiffanie0360/iron-oxide-wash-ceramics/
-
Some previous threads on Mocha
PS Ceramic Arts Network search
https://ceramicartsnetwork.org/search-results?keywords=mocha -
-
-
A little more detail and a tiny cautionary note.
https://shop.brackers.com/magma-miracle-anti-gravity-multipurpose-additive/
MAGMA will dramatically thicken any glaze it is added to. Thinning the glaze to a “normal” consistency will cause very thin coats. MAGMA containing glazes must have more viscosity than typical glazes. MAGMA glazes also take more time to “dry” (the water moves into the bisque slower) after dipping or spraying. If high viscosity glazes will not work for you, and/or slow setting or drying glazes will not work for you, you should not use MAGMA. -
-
It's a problem that has perplexed the scientific community as well.
https://en.wikipedia.org/wiki/Teapot_effect
https://scitechdaily.com/why-teapots-always-drip-scientists-finally-explain-the-teapot-effect/ -
Jordan: what cone/temperature are you firing to?
Kelly: information seems thin on the ground. Continental's web site seems only to say cone 6-10, and mentions both oxidation and reduction.
https://www.continentalclay.com/products.php?cat_id=415&sub_categoryID=255
- Min and Kelly in AK
-
2
-
6 hours ago, Lbauer12 said:
Anyone at all 😆
Ask Sheffield?
PS I'm a bit confused by this:
http://www.potters.org/subject90762.htm
I also tested 4D3BM. I still occasionally use it and find the M^6G glazes fit pretty well.
... I wonder if this was at ^5 or ^6?
I notice that the 4D3MB's shrinkage and absorption is given at ^6. To me this feels odd for a ^5 body.
https://www.sheffield-pottery.com/4D3BM-Dark-Speckled-Stoneware-Moist-Clay-Delivered-p/mc4d3bmfs.htm... and this:
https://glazy.org/recipes/352480
Cone 6 med fire, no hold. Sheffield T6, 4D3BM, 20266 porcelain, Liz's White. 2 dips. S.G = 1.47.... anything of interest here:
-
8 hours ago, Pahi said:
I can’t open the book attachment above. Link says it’s been removed. Does someone have one they can scan and send to me? I’m happy to pay.
Johnny's "embedded" link didn't work for everybody, but it did work for many people (including me). At the time I posted an non-embedded version of the link which should work for everybody. (Both forms of the link still work for me.)
PS Note the mention of an optional "reversing plug" on the 5th page. If your wheel doesn't have this fitted maybe reversing these leads would work. (Probably best to start a specific thread for advice on this?)
PPS Also see http://www.potters.org/subject53032.htm
wheel direction reversal question -
> One way to manage the stinky mold is to stick a couple pieces of copper wire (or use a copper container) in the slip and water (or hang Copper Pennies). Most molds don't like copper.
Just to point out that the amount of copper in "copper" coins has dropped over the years, and it's bioavailability has probably dropped even more. However a more recent shift has been towards base-metal coins electroplated with copper. Where the limited copper should be highly bioavailable again.
http://www.americanplatingcompany.com/copper-in-a-penny/
The first change came in 1856 when the “Flying Eagle” scent started production with of 88% copper. In 1864, after the Civil War, the design changed again with a 95% copper 5% zinc make-up. Finally, in 1982, the coin would evolve into its modern form of only 5% copper and 95% zinc. The modern penny has the least amount of copper with a small 2.5% copper plating and a 97.5% zinc base.https://en.wikipedia.org/wiki/Penny_(British_decimal_coin)
The coin was originally minted in bronze (composition 97% copper, 2.5% zinc, 0.5% tin) between 1971 and September 1992. However, increasing world metal prices necessitated a change of composition. Since 1992, the coins are minted in steel and electroplated in copper, making them magnetic.- rdroza, Kelly in AK and Rae Reich
-
3
-
On 6/4/2024 at 11:06 PM, Hulk said:
Paragon Industries has a wiring diagram and parts identification .pdf for models A-99, A99B, A100B on their website; pick it from here:
Kiln Wiring Diagrams | Paragon Industries LP (paragonweb.com)I'm not seeing a timer there, however, see "...kiln sitter (not shown)" under item 22.
Is the timer motor part of the kiln sitter? If so, please ID the sitter make and model, and, if possible, supply an image?As Tom said, the timer is probably part of a kiln sitter, perhaps one of these:
http://www.fireright.com/docs/kilnsitter/lt3andk.pdfIf you can confirm that it is indeed part of a kiln sitter -- and tell us the make/model (preferably with a photo) -- somebody will be able to suggest a supplier.
For an idea of price, picking a random make and model of kiln-sitter I quickly found:
https://www.theceramicshop.com/product/7940/kiln-sitter-timer-motor/
...assuming that it is the motor that you are afterPS PM'ed as OP hasn't visited since posting the question.
-
Thinking about how the initial wiring overheated both infinite switched (≫15amps per switch) and didn't trip the 30amp breaker(s).
I suspect that the two element were in parallel across 120volts giving about 2*(120v/10Ω)=24amps. Rather than two elements in series across 240v giving about 240v/(10Ω+10Ω)=12amps.
Emphasising Bill's point that you will now only need the neutral connection for wiring the pilot lights, not for any connections to the elements.
-
-
What size breaker do you have installed?
-
Might it be worth trying (atmospheric) reduction in a saggar?
PS As it's porcelain perhaps aluminium foil saggars aren't suitable:
-
1 hour ago, Kelly in AK said:
No trickery here, just a very strong magnet.
For clarity, I assume you are talking about Neodymium magnets.
I remember my shock when I first met them, they are qualitative different from traditional magnets aren't they. But quite cheap and freely available on ebay etc.
H&S warning. When swallowed they can seriously damage the stomach (especially by pinching the stomach wall between them). So keep them well away from children.
https://rcem.ac.uk/wp-content/uploads/2021/10/RCEM_BPC_Ingestion_of_Super_Strong_Magnets_in_Children_170521.pdf -
A few refs on how local reduction in glazes seems to work. I'm inclined to feel that the mechanisms don't apply to local reduction of (most?) bodies.
I suspect that silicon carbide needs to be in really intimate contact with whatever it's reducing. Usually this seams to mean in contact with the liquid glaze.
BTW the mesh-size of the silicon carbide can also affect the results. In general pottery suppliers usually sell a coarse mesh.
An interesting paper on copper reds, which covers a wide range of local reduction issues.
https://tomturnerporcelain.glazy.org/downloads/CopperRed_35DE.pdf- Min and Froufrouis
-
2
-
16 hours ago, Dick White said:
The files are just one long list of the status of the firing every 30 seconds. They are in .csv format, which is one of the formats that the usual spreadsheet suspects (Microsoft Excel, Open Office Libre, Apple Numbers) can open. Once the list is open in the spreadsheet, you can look for unusual events, or do some calculations on the actual temperature changes over 1 or 5 or 10 minute intervals to compare to what was programed. And if you want to get fancy, use the graphing capability of the spreadsheet to draw a picture of the temperatures over the duration of the firing.
I think this is a graph of one (or should that be a smooth graph based on the data in one)
-
10 hours ago, Mudfish1 said:
Hi Folks! Does anyone have experience with the glazes in Tichane's "Celedon Blues" book?
I am working with his 5-3-2 recipe (50% feldspar, 30% silica, 20% whiting), which settles out and pancakes rather spectacularly.
Does anyone have advice about additives that won't mess up the final blue celedon color?
From a position of complete ignorance ... you might be interested in looking at the approach used in 5321.1
https://www.derekau.net/blog/2015/01/19/blue-celadon-glazes
Celadon Blues ...
The “532.1” formula contains 50 parts feldspar, 30 parts silica, 20 parts limestone, and 1 part iron oxide. The “5321.1” formula is the same but adds 10 parts kaolin. The type of kaolin added greatly affects the color of the glaze, for blue celadons a kaolin very low in titania such as Grolleg or New Zealand Halloysite is required.https://digitalfire.com/material/kaolin
Kaolins are employed in glaze recipes to keep the silica, feldspar, frit and other particles from settling out (the surface chemistry of the particles and their interaction with water are responsible for this behavior). At the same time the oxide chemistry of kaolin makes it the primary source of alumina oxide for glazes. -
From the two names in your picture:
Have you tried contacting Kilns & Furnaces Ltd?
https://www.kilns.co.uk/
https://www.kilns.co.uk/contact-us...and Pottery Supply House
https://psh.ca/pages/firecraft-kilns
On November 4th, 2004 Pottery Supply House acquired the assets of Firecraft kilns. We will be pleased to assist you with any equipment or supply requirements.
Kiln blowing transformer with new elements
in Equipment Use and Repair
Posted
What was the rating of the transformer(s)?