Jump to content

Min

Moderators
  • Content Count

    4,125
  • Joined

  • Last visited

Everything posted by Min

  1. Hi Bill, Okay, so I'm just poking around with the EuCalc, I'm using a Mac. I took Sue McLeod's clear from Glazy and plunked it into the calc. Don't know if one would get the same results using Excel? Looks like there is excess alumina and silica that isn't taken into the melt but I could be reading this wrong. I'm heading out early tomorrow a.m. to go wilderness camping, won't have a chance to play with this some more until I get back Sunday night.
  2. There was a recent thread where glaze eutectics was brought up. Stemming from that was a link to an article by Robert Magnuson in the Feb 2018 Ceramics Monthly which contained a link to a eutectic calculator, "EuCal", he created. Magnuson discusses an interesting aspect of eutectics, to quote from the article: "One of the most interesting aspects of eutectics isn’t how they melt, but how they solidify. When a eutectic mixture cools from the molten state, the individual components all stay molten together until they solidify. When they do, a transparent glass is formed. If the molten glaz
  3. A length of sheer pantyhose stretched tight works well as a barrier. Pull it taunt and hold it in place with rubber bands or duct tape on the inside or underside. Doesn't seal off the mold the way plastic film does so some moisture can still escape, clay releases easily from it.
  4. Glad you like the syringe tip Mark!
  5. There was an article a number of years back from Britt about kiln wash, including one that had 1-2% G-200. The recipe came from a ceramic engineer for a company whose kilns had high turbulence. They wanted the wash stuck enough to stay on the shelves, used enough spar to have it so they could scrape it off with a fingernail after firing.
  6. If this kiln is new to you I'ld check the kiln sitter is calibrated properly then put your small cone or bar, (bars are more accurate, cones are somewhat adjustable) and fire to cone 6. (link below on how to do this) It's probably going to take a few firings to learn how your kiln fires. Easy way to get the glaze off the bottom of pots is to wet a piece of thin foam, carpet scrap, or even a few layers of fabric then turn the pot on the wet sponge. Gives you a clean glaze line around the edge. Give them a final pass with a clean sponge. Since you are glaze firing for the first time I'l
  7. Yes, it's one heck of a lot! Expensive stuff to be using at 20%! Having half the recipe made up of borax is really unusual too since borax is water soluble. Could you post a picture of what it looks like when you've got some pots done with it?
  8. When I look at the info for the BIZ BOD is has this: So at cone 10 the absorption is just under 2% (plus or minus 1%), this means that if you fire it to cone 6 the clay will be more absorbent. It's best to use a cone 6 clay fired to cone 6 for functional pots. The clays greatest strength is when it's fired to maturity, not underfired. Plus the absorption will likely be high enough that with use it will soak up water/moisture from doing the washing up which can lead to other issues; pots will get very hot in the microwave as the moisture turns to steam within the clay, glazes are mor
  9. That's a Val Cushing recipe and like Dick said it is complete as ball 30 + borax 50 + tin 20 https://glazy.org/recipes/30484 (There are some test tiles on the link from Alfred with it fired to ^6, looks pretty dry / underfired when used alone.)
  10. Looks like BIZ BOD s a cone 8 -10 clay, are you firing that high?
  11. What's your current schedule and what is the other person's? Is the stoneware a darker bodied one?
  12. Looks like you got a tiny bit of the green in the first picture where the glaze was probably thicker. When you glazed the pot in the second image did you double dip the top part? I'ld make up some tall test tiles, single dip one, double dip another and triple dip a third and see what happens. Count off how many seconds you are dipping them for and make note of that. Test tiles should be roughly the same thickness as your pots, and bisqued to the same cone, so you get the same glaze thickness on the test tiles.
  13. You are better at waxing than I am, I kept getting drips of wax from the brush onto the pots when I did it this way. Find I'm less messy with the cold resist for this.
  14. I've found there is a night and day difference between the different brands of cold wax resist. Sounds like you use one of the good ones. I love Forbes resist, dries fairly quickly and resists really well with no stickiness. The unbranded resist the local ceramics supply place sells pales in comparison; it takes ages to dry and even then it's still a bit sticky and doesn't resist nearly as well as the Forbes. It's the hot waxing process to get the wax line that I find way faster than using cold resist. For most of my work I do a mix of the two, I dip (soy wax) anything that I can then to
  15. Jeremy Willis (professional engineer) has been designing kilns since 1984 for Pottery Supply House / Euclids. He is a managing director of The Pottery Supply House and the manager of Euclid's Elements. Willis's predecessor, Eric Poschmann, has a brother who owns and operates a heat process technologies company by the name of Synergetic Technologies who does work for Pottery Supply House / Euclids. Synergetic has been around for 35 years. Given their decades of experience and qualifications, I would trust they know what they're talking about.
  16. +1 for this. Have a look at some of the commercially made dies, they are tapered downwards like the ones below. I'ld also toss the first few inches of the extrusion if it has a bend or curve to it.
  17. @sushaw and @graybeard, the op hasn't been on the forum for about 3 weeks so I'ld send them a pm. (they will get an email saying they have a message) Looks like the op is in San Bruno, CA.
  18. Get the analysis for any other available talc you can get in Mexico then compare the chemistry to the TexasTalc. There can be quite a difference in talcs, example would be Sierralite talc which is high in alumina compared to Amtalc. Once you have the analysis for what's available to you then it's a question of balancing the 2 analysis's and adjusting the clay formula to match. Welcome to the forum.
  19. Since you are firing so frequently I'ld factor in the time it takes for the kiln to cool also if/when you replace the kilns. I've owned electric kilns that had 2 1/2" walls, 3" walls, 2 1/2" plus 1"fibre and a couple that had 4 1/2" walls, noticeable difference in cooling times. An issue with having insulating boards is if/when you need to change a brick, dealing with the insulation adds to the job. Another factor is the thickness of the lid and the floor. Re ConeArt kilns, I don't know if they all do but the one I have has a section in the middle of the kiln with no elements. There is an elem
  20. Is this a product sold for ceramics or something else? When I think of an activator I think of something, other than the catalyst, that increases the rate of a catalyzed reaction. I can't think of ever seeing a deflocculant that cause pink liquid and foamy bubbles like you have.
  21. You are right! I saw it as handle going upwards. In that case I'ld probably scrap the piece and start again. If the handle is wedged in there there are probably going to be cracks in the clay from being shrunk tightly onto the handle.
  22. It's sounds like a stiff ^6 majolica type glaze might be what you are after. Glazes are like clothes, some will fit and some won't. You will need to test for glaze fit with the claybody you are using. Try doing a search on Glazy or the Digitalfire website or John Britt's Complete Guide to Mid-Range Glazes book, there are lots of sources for recipes, from there it's a question of testing them with your clay, techniques and firing conditions. I know it sounds like a lot of work for a simple question but it does take testing. Welcome to the forum.
  23. Yes, I would do this. Looking at your picture it appears you could take a small pair of scissors and cut the brush off the bristles. Once the bristles are no longer attached to the ferrule most of the bristles could probably be taken out with a pair of tweezers. If there are some still stuck to the clay I wouldn't worry about them, they will burn out.
  24. Okay, so if all you need is a glossy white you could take your recipe and subtract 36 dolomite from it. This is the third recipe in the green boxes I posted above, just replace the F4 with Minspar 200. It looks like it should fire to a durable white gloss at cone 6 with the reduced dolomite. Boron is higher than it needs to be but should still be okay. I would suggest mixing up 100 grams of the base (you don't need the bentonite in there) then adding 8 zircopax, dip a test tile that you have some of your underglaze/slip/oxides on or overtop, depending on how you normally do it. Now add another
  25. Silica and alumina levels are too low with either Minspar 200 or the original F4 I agree with subbing Minspar for the F4 and not using Nepheline Syenite but it still won't make a durable glaze.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.