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  2. hitchmss

    Ceramic Table Legs

    I had not thought of it in terms of ceramic coatings! That would be an effective way to treat the steel legs! The filling of the wood surfaces's voids though...
  3. tinbucket

    Glaze Chemisty Education

    In the meantime, you can read these sources online which I have found to be very helpful. The first two links are articles written by Matt Katz and others. UMF may seem very difficult to understand at first but once you understand the general concepts it will be very helpful in your glaze formulation. I recommend looking at Glazy.org, especially the calculator function. Glazy is great because it tells you what oxides (silica, alumina, sodium, calcium, etc.) and how much of each is being contributed by the glaze materials. The calculator allows you to adjust material amounts and see how the chemistry changes in real time. It can all be very overwhelming but the more you read the more you will understand and have control over your glazes. https://www.ceramicmaterialsworkshop.com/reports--publications.html https://ceramicartsnetwork.org/wp-content/uploads/2008/10/TF_BoroninGlazes_0912.pdf http://help.glazy.org/concepts/analysis/#unity-molecular-formula-umf https://digitalfire.com/4sight/troubleshooting/index.html If you are more of a visual learner, it may be helpful to do a Currie grid test of a glaze you like. More information on that can be found below: https://wiki.glazy.org/t/currie-grids/183
  4. Oh ya I recall these-I forgot about them. Very nice-maybe I should order some out of porcelain from you?Couple 100??only kidding
  5. Today
  6. Mark C.

    Bisque firing help please

    Use a soft vacuum brush to clean out the small blown up bisque ware from the elemnts -they need to be clean or a crevice tool but do not touch the element with that hard plastic tool end. The element damage very easily . But they need to be clean of exploded pieces to be fired again. dry your work more and go slower with heat.
  7. Fred I got that east /west screwed up as I was sitting on the couch with a cup of hot coffee in a bone chilling 70 degree dining room. I shoulkd know better as my Brother published a book called East west back in the late 80s.I have a copy-its an art book only a small run made.
  8. Many thanks everyone! I greatly appreciate all your advice on how to best calculate things. I will do some test pieces and see how it goes. :)
  9. Bev77

    Bisque firing help please

    Thank you so much for your answers. I will definitely take your advice and try this method.
  10. liambesaw

    Ceramic Table Legs

    I was thinking he meant like cast iron enameling
  11. hitchmss

    Bisque firing help please

    Agree with Liam; pots exploding are almost exclusively caused by moisture converting into steam, expanding rapidly, and blowing the pot up. Water converts to steam at 212* F, and expands 1600 times its volume, that's a LOT of expansion! Even when my pots are nice and dry, and I dont have super thick to thin areas which could hold moisture differently, I will generally hold the kiln at 210* for about 30 mins or so, to make sure all the physical moisture has been driven off, before I could potentially convert it to steam. With manual kilns (switches and kiln sitter, not control panel and thermocouple) when you turn a switch to a heat setting, it will provide a constant amount of heat at that setting. That amount of heat MAY be too much given some circumstances. Its common, with manual kilns, to leave the lid propped 1-2", and only turn the bottom switch on LOW for a few hours, or even overnight. Heat rises, and the bottom elements will warm the work up top too, the lid being open allows heat to escape, and not get above that 212* point. The lid can then be closed, give the kiln/work some time to adjust to the lid being closed (1-2 hours) and then turn all elements to low, 2 hours later all to MED, 2 hours later, all to HIGH until done. 1-3 weeks may be your issue; unless I am running a dehumidifier, or sitting pots in front of a heat source, even my very thin walled pots are rarely ready to fire 1 week after making(Ohio, dampish climate). 90% of the moisture may be gone, but they are not ready. Use the back of your hand, or hold a pot to your cheek (both skin surfaces which are more adept to telling temp differences than the rough insides of your hands) to check for "coldness". If you have a heat source in your studio, you can always stick pots in front of that, before firing, to allow them to dry out further. It takes time and practice to learn when pots are "good to go". If they are varying colors of "dryness" then they definitely are NOT ready to fire. It COULD be a technical issue with your kiln (im thinking something silly, like maybe the dial for a switch is improperly aligned (showing low, but it actually means HIGH)), but with manual kilns there's not a whole lot to fail to cause rapid heating issues. Id do one switch at low for a while with lid cracked, then all switches to low at a later point. This should fix your issues.
  12. C.Banks

    Ceramic Table Legs

    or its close cousin hypertufa
  13. Fred Sweet

    Ceramic Table Legs

    Dado- + to what hitchmss says. Do a search internet search for epoxy river tables. You’ll find plenty to look at for ideas. Added benefits include less experimental time, proven technology, clear and opaque material availability, ease of construction, and encasing the metal legs doable, and able to be done without the need for equipment and skill sets which may not be available onsite. Fred
  14. hitchmss

    Ceramic Table Legs

    Not sure what you mean by "ultramarine" ceramics. Are you meaning the color, or a specific clay body. If the latter, I am unfamiliar with this. Heres the issues I see; you want to encase the steel in ceramic. You're not gonna want to fire them both together because the clay will shrink and break around the steel as it fires. Likewise, your pretty piece of steel will now have oxidized greatly, and cleaning it up will be a major PITA. If you fire the ceramic seperate from the steel and want to join them after the fact, you will have to find the proper material to join the steel/ceramic; you will also have to calculate very precisely the shrinkage, so that the clay will have a snug, but not too snug fit, after the firing, to the steel, and still have enough room for your adhesive of choice. Of course, you could always make the ceramic much larger, and fill the cavity with an adhesive, but may not be the look you like. If the clay warps during the making or firing, your pieces may not fit at all. Second, if you are counting on the steel being the structural supporting member, this means that the ceramic can't be load bearing (and shouldnt be, lest someone sits on your table, and chips a foot/leg), and if it cant be load bearing, then it cant go all the way to the bottom of your steel member, meaning you will have exposed steel somewhere. Unless you hide it with some kind of cover/plate. There are plenty of kilns which are big enough to fire what you want; most "hobby" potters have kilns which are big enough to fire this. Industrial kilns are big enough to drive buses into them. Not sure about the access over in the UK but there should be plenty of community studios with kilns large enough. Air dry clays could withstand a certain amount of moisture from expected use/spills, so in that sense it will survive better than water based clays, however they are not nearly as durable. They also shrink (not sure exactly how much), so you will have gaps as the clay dries. As well, there is no way to "glaze" them, as you'd have to heat them. Paints/enamels would work, but may not be the finish you want (durability wise). All in all, Im not sure why you'd want to use ceramic at all. The material doesnt shine in situations like this, and doesnt provide any better surface than what you could achieve using other methods. Id sand your steel legs to the perfect finish, and then paint them with auto body paints which will have a TON of color choices, and are very durable. The surface you can achieve will be as glossy/durable as any glaze (likely in some cases more durable) will be. For filling the voids in your table's wood, I would use an epoxy resin; there are a number of manufacturers of resins, and lots of "models" of resins, which have their own benefits over others. They can be tinted with a lot of materials, even encapsulating larger materials that are "mixed" into the resin. Their shrinkage rates are barely noticeable on a scale like you're working. I know a number of artists who use this method to make table tops. The wood surface and resin can be planed at the same time, so you can have a perfectly consistent surface. The resin can be sanded for a frosted look, or polished for a clear as glass look, painted for color................. There are a number of "furniture" items which have been made from ceramic, but with your proposed project, I dont see the benefit, and in reality, poses more challenges, especially if you dont have much experience with clay. Just a question, why use ceramic at all? You have a reasoning I assume?
  15. liambesaw

    Bisque firing help please

    Either the pots were thick and had moisture trapped, or they got too hot too fast, or what is more likely is both. Even heating is important, especially if there are thick or damp pieces inside, so maybe a piece next to the elements was thicker and blew.
  16. Hello, I acquired an old used Duncan kiln w/kiln sitter. I never used a kiln before and my first bisque fire went great. My second not so much. I had quite a few pots explode. I did some research and thought I found out this happened because the pots were not dry enough. So today I was going to fire low for an extra two hours and within 30 minutes I heard a pot explode. Everything that was in the kiln sat drying from 1 to 3 weeks and were not "cool" to the touch. Can someone please tell me what I am doing wrong before I ruin anything else.
  17. Magnolia Mud Research

    Advice - How to fit cork lids for canisters?

    for a while I was making jugs that were plugged with corks. I finally settled on one cork and wrapped the cork with masking tape (the blue stuff) to create a tool to make the correct hole size. Took several tries to get the number of layers needed for my clay body, but the 'tool' works fine. the 'tool' solved both the size of the hole and the angle of the taper right for the corks I wanted to use. For larger corks the idea should also work. LT
  18. Tyler Miller

    Ceramic Table Legs

    The material you are looking for is concrete. Cheap, castable, available in every country on Earth, and sets without firing.
  19. Hello everyone, I would like to have a chunky table made which consists of four ceramic table legs and a wood on top. The table legs (W200mmxD200mmxH700mm) can be a rectangular steel hollow section (200 x 200 mm, 700 mm in height) that then gets encased in ultramarine glazed ceramic. I worked with kilns when I was an architectural student, but now am curious to see if there are techniques or ways of doing these legs without firing them, as I am not sure any kiln could take that big size. I live in UK and can get decent raw materials, but the project is in Croatia and I am not sure if they have kilns in the vicinity of the house. Second question, the table top would be made of ragged shaped planks that would naturally leave gaps between each plank as the wood curves in and out. I would like to pour ultramarine ceramic into these gaps, but again I won't be able to fire these free-formed ceramic stitches in the kiln as the wood would burn. Can I do anything with air drying ceramic mixture, is there anything like that? and then glaze it with some other solution on top? I appreciate all your suggestions and tips. Thank you and all the best, Dado
  20. I've found that one of the greatest benefits of working at cone 6, regardless of what type of kiln you use, is the abundance of commercial glaze products. If I need a certain color to use as an accent for a special order I can just buy a pint. Or if one of my students wants a glaze color that I don't have, they can buy their own. My students are happier knowing that they aren't limited to the glazes I provide in the studio. I would totally explore cone 6 reduction if I had a gas kiln. I've seen some nice work coming from that, and the fuel savings are huge compared to cone 10.
  21. liambesaw

    Hardening of glaze

    I meant as part of the recipe. Some people say percent but that's a misnomer because recipes don't often add up to 100%. If you use the word part instead it makes sense.
  22. Grace london

    Hardening of glaze

    Ah OK, so there is no way around this issue then...
  23. Glaze takes up a surprising amount of space in a hole, especially because cork tapers don't leave a lot of wiggle room. 1/16" makes a huge difference in how deep the cork sits. It would be smart to make a couple test pieces to be sure.
  24. Grace london

    Hardening of glaze

    This is an old test tile, but you can see the matt surface and they all flow and blush together...
  25. Min

    Hardening of glaze

    It will still make crystals even if mixed thicker. Sieve them out then microwave them with a bit of the glaze slurry then when they are melted stir the heated slurry back into the glaze bucket.
  26. Grace london

    Hardening of glaze

    I use it for sculpture Min, though I've been told it was safe. It's a beautiful low matt satin that I have found perfect for my decoration, quite reluctant to change as it works so nicely for me. Nothing missing. Perhaps if I make it thicker it might not form cystals?? Thanks
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