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blackthorn

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Everything posted by blackthorn

  1. I have also been using mylar sheets on a Cricut. https://www.amazon.com/dp/B089W3Q5X4/?coliid=I3FTUFDEJF3F8G&colid=JTV78ROEQ2AV&ref_=lv_ov_lig_dp_it&th=1 These are 12"x24" but they also sell 12"x12". Tyvek is easier to cut by hand but mylar can also be cut by hand and pretty easily if you use something like a wood burning tool or even a soldering iron.
  2. From what I found in my research on slumping glass onto ceramic substrates: Fire the kiln to a temperature between 1200 to 1300°F (648.9 to 704.4°C), keeping an eye on the glass through the peephole. The glass will begin softening and turn glossy when the temperature nears 1000°F (537.7°C) and start slumping as it nears 1200°F (648.9°C). Sadly, I think this is much higher that the silver in Liquid Light can endure but have yet to confirm this. It will likely dissapate above 1000ºF. It's on my list to test but will require dedicated kiln time at the school and we're in the middle of a term with students scrambling like ferrets to have their work fired. Still, sounds interesting and I'll pursue it as time permits.
  3. Just finished two days of pugging many hundred pounds of clay for the students this coming term. Imagining now having to Zoom the classes.  Again.

    1. Mark C.

      Mark C.

      clay keeps well

    2. blackthorn

      blackthorn

      I'm certain some of this was soaking in those buckets for almost a decade.

  4. From earlier today. This will bisque to a light toasty brown. Any higher and it will dissipate completely.
  5. I'm also interested in spraying glaze and slip. Here are a few links that I've found helpful: https://www.youtube.com/watch?v=4btURLgFOzQ https://www.youtube.com/watch?v=L0jS2U6PPCE https://www.youtube.com/watch?v=1LiZ7V7CNTE https://www.facebook.com/watch/?v=1474038826090633 Tom @Hulk is right about the spray gun. Geil sells a good one for something around $40 US dollars.
  6. @PeterH To your points 1 and 5 - I posted images of some of my recent tests earlier in this thread. To your point 2 - I've found this to be true of fully vitrified stoneware and porcelain, so I coated it with a combination of equal parts of Whiting, Gesso and water. It remains stable long enough to allow for exposure, processing and firing if it done within a day or two. I haven't tried it yet but I'm also going to spray paint flat white, sand and repeat a few times, on a fully fired slab to see if it allows cyanotype to not bead up. Gum or gelatin will bond to the painted and sanded surface.
  7. Reading just about any book on Ceramics will provide info on pigments that are used, and the better ones will describe the behavior of most at varying temperatures. Since we know that: "Glass melting is performed at temperatures between 700°C and 800 °C which correspond to an optimized value of the viscosity for glass refining and shaping", we can surmise that firing an exposed and processed sheet of glass will begin to flux at temps nearing that. Experimentation would be essential to see 1) How high is high enough to completely bond with the surface image; 2) How high is too high, which would result in partial or complete distortion of the image, ala Salvador Dali; 3) If it's even possible to sufficiently melt the glass without it bonding to whatever cookie or shelving it's resting on during the firing.
  8. I'd never stack any glazed pieces during firing to any temperature. It sounds like your trying to save on space/time with this technique, right? I have an awful lot of slab work and I bite the bullet and use lots of shelves and short risers. Another question might be, would you do it for some of your own work that you really cared about successfully firing. That's my thought. Best of luck.
  9. I purchased my supply of Potassium Dichromate from Bostick and Sullivan but a quick Google search will turn a dozen more places, like another of my favorites: The Photographer's Formulary. Here's a link to Bostick and Sullivan: https://www.bostick-sullivan.com/cart/3/109/ Yes, it's toxic. Maybe more so than Cobalt and perhaps Barium but handle with good and sensible care and you'll be ok. ps. Some low fire glazes actually call for Potassium Dichro. Just saying.
  10. Absolutely Peter. Iron, Cobalt, Manganese all can be and are used as pigment in gelatin or gum dichro printing. The ONLY thing one has to watch out for it the amount used. I can attest to the fact that if too much of any of these is used then the emulsion becomes to opaque, like parts of the negative and blocks the exposure. So much of the emulsion simply washes away after exposure. Less is more with both oxides and Mason Stains and interestingly enough, that includes Mason Stain White, which I've used with film positives on dark clay bodies, instead of a film negative. But, @jsmoove, your point about testing is, of course, correct. I'm still doing that. I've found many ways how not to make these processes work. I have no experience with glass work but admire the process. There are only so many hours for me and that's another rabbit hole in which I could easily get lost.
  11. Thank you! I've attached the schedule from the Geil Electric here.
  12. I often use Aardvark Black Mountain, but it's ^10 and requires a lengthy and slow bisque or it will definitely bloat. Otherwise it looks wonderful, like your Midnight Black. No idea if a ^6 Black Mountain exists.
  13. Mark's comment on eating Fair food and getting ill reminded me of the time I got food poisoning and my wife had to do the tear down and packing all by herself as I writhed, sweating in agony. Subsequently I planned my fasts around events and just drank tea and water. Two or three days was not a struggle. Not a very exciting response to the original question I suppose but there it is. I'm extremely unlikely to eat street vendor food from any location ever again.
  14. Ok. Like you, one of my goals is to create an absolute permanent image, and, as it happens for my part, to make it on ceramic. While I like the cyanotype process, my next project involves the other video link I posted - Carbon Transfer. What I'm doing is creating the emulsion of Potassium Dichromate, Mason Stain and Gelatin. I pour that on Yupo and let it dry in full dark. After dry, I get the enlarged negative of choice and expose it. I've also prepared a bisqued slab coated with a mix of gesso and Whiting which is then coated with gelatin and hardener. The exposed Yupo/gelatin substrate is sandwiched with that slab and set in a tray of hot water until the gelatin releases from the Yupo and adheres to the slab. Yupo is peeled away and washing continues melting away all the unexposed gelatin leaving the exposed (hardened) image. Now it's such a thin coat of gelatin that during firing, as it melts, the actual image suffers minimal distortion. One down side is getting an image onto something thrown or more dimensional than a slab. Of course the absolute major challenge is to find an image that integrates into that form and not just having an image on it for the sake of having an image. I'll post an image of then when successful.
  15. Thank you Min! It's actually in my front yard pretending to be just that, along with some fossils I made just for that purpose.
  16. As for the cyanide gas release during the firing, yes, the kiln is outdoors and well away from any human traffic. Even so, the amount of hydrogen cyanide is really quite small given the coverage of the pieces you see above. As you say, you want to render your image permanent on the glass. Firing is both unnecessary and most likely ruinous. In order to use glass as an initial substrate like the fellow in the link below the glass has to be of reasonable thickness to allow for handling as well as support of the image. That would make it at the very least 1/16th of in inch thick. Regardless of how the image is affixed to the glass when is fired that image will most likely go all Salvador Dali and become unrecognizable. Could be interesting but it's a grand toss up. As you mentioned wanting to commit your artwork to glass specifically, so here are some links to two fellows doing just that. Keep in mind that their works are finished pieces and would never survive a firing at any temp. And your point about the Liquid Light is true, given the melting point of Silver Nitrate is something you can accomplish in your household oven, right around 450º F. There are a few ways to render a permanent image on high or low fired ceramic surface but to the very best of my knowledge they don't involve an initial glass substrate. Then again, I could be wrong. Here are ways to render images on glass pretty permanently - without firing: Cyanotype on glass: Carbon Transfer Printing on Glass:
  17. @jsmoove My background is also in photography and my projects of late have revolved around getting a stable photographic image on ^10 ceramics. I've not tried any glass work but am having plenty of success with a handful of techniques, most of which involve direct contact exposure with a large format negative. I've previously posted a few imageson the forum here so won't take up additional space re-posting those but the ones here are more recent takes on the two most successful techniques: cyanotype and gum bichromate. Cyanotype is lovely, both unfired and fired. Although it's main light sensitive constituent is iron, the iron is fugitive at higher temps. I've not yet tested it's high limit but at bisque it comes off a nice toasty brown. The gum bichromate is just like the paper print process though instead of watercolor pigment typically used, I mix mason stains or Manganese Dioxide with either Gerstley Borate, Frit 3124 or some clear glaze recipe as a binder. So far all of my tests are on slabs but I'm constructing an exposure unit that will allow for 360 degree exposure for taller thrown work. I know it's a bit off topic from the ground glass rod query in the op but it does speak to the process of fixing true photographic images onto a ceramic substrate. There are a couple of other processes I'm exploring but the results have been a bit weak so far, but still have some possibilities. Happy to discuss if you're interested.
  18. We have a couple of dozen of these at the local college and I'm in the process of buying another dozen. As for cleaning off glaze drips, it's much easier than the older shelves. My friend is a crystal glaze enthusiast and he takes pretty good precautions for the runny mess at the bottoms. However while I was unloading the kiln I noticed that two pots got away from him. With mild dread I anticipated a major clean up or damage shelving, but no. With 30 seconds of scrubbing with a hand grinder the shelf was back in service. I do take extra care to keep them well covered when not in use. Rainfall here in the desert is minimal but we still keep them safe and dry. Covering with trash bags in the kiln storage area works just fine. My friend is 86 and even when I can't load his work he can easily handle these shelves. In that respect they are definitely worth the extra cost they go for.
  19. The acrylic is definitely repelling the glaze. I use acrylic or gesso frequently as a resist on both green ware and bisque. Everything Babs says is perfect and will solve your problem. And welcome to the forum. Lots and lots of useful information here and many experience crafts people as well.
  20. After reading the lively posts on thiamant's vent topic I'm thinking I don't need any venting on mine since it's located outside on a 3 sided patio. Right?
  21. Thanks for the helpful info and you're right, a grand is not cheap. Like Mark said, it's also a bit overkill. I do like the idea of the Olympic Electrositter. Something I may look into when I've spent some more time firing this unit.
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