It's time for the monthly attempt to make a ceramics/sculpture/clay thread.
Here are some buttholes I made out of ceramics.
pls stop being degenerate, what would bubbe think?
They aren't intended to look like anything. I just stumbled on a particular way of folding clay. A lot of the time this method creates an invaginated, butthole like shape that I enjoyed. Clay is cheap so I made a lot of them.
That's what I plan to do with them. First I tried to mount them on the wall in various configurations but in the end I arranged them in a circular pattern on the floor. I left my camera in my studio with pictures. These were just ones I took with my phone.
hey gang, ill dump some of my stuff to spice up this thread.
You might consider buying some underglaze pencils if you interested at all in drawing on porcelain. It's what I've been doing for a while and I like it quite a bit.
not need to buy them i make em myself along with glaze pencils.
plus for that series it was mostly conceptual and i did not want to draw on the porcelain.
I've never been able to get the ration of undergrlaze and binder right. They're either too hard or they leave behind a dust that doesn't like to stay put and is easily smudged or is blown off the work in the gas kiln.
Naked. Adding clear glaze will make some of the dunderglaze diffuse into the glaze making it rather blurry. If you take the drawing up to cone 6 or 7 the underglaze will vitrify to the porcelain. I even run them through the dishwasher when they get dirty.
Here's an early example when I was just learning how to draw. It didn't get all that blurry and I kind of like the look but I've had to throw out pieces that were ruined because of it.
nioce, i like the platter shape.
do you do vessels too?
Rarely. I did all the plates and cups for my wedding with the idea that the guests would take their's home as the wedding gift but I don't really do it for fun or profit or anything like that.
worth a try imo.
i have some images of extreme over firing of terracotta somewhere, shit bubbles and warps like crazy, great fun.
1350 was top temp and floated for 3 hours there. with a VERY long cooling.
i tried higher but it would always glass over. but at this temp terracotta gets a metallic like sheen almost.
Just uniform. i had
to make 100 sets. I was just churning them out. >>2378895
Overfireing porcelain won't do that. It will slowly flatten out and cause thick cracks around the edges. If it cracks all the way through the pieces won't fit together. It's not like dunting where you can just use epoxy to fit the pieces back together.
I don't have any of the cups left but I do have some extra plates. They're very basic with a simple iron boron glaze.
Yeah we are and we just bought a house in Seattle so I don't have a studio currently since I need to get an ellectrician in here to do some rewiring. We go to couples counceling pre-emptively since we're both trauma survivors and don't want to fall into bad patterns of behavior with out the tools to work on them. We were together for 5 years before getting hitched so we had some ideas about what to work on and it seems to be working. We can probably stop going soon.
Here's an example of that type of cracking that I'm talking about. Since a slab has no real structure to hold it together like a cup, the edges heat up way faster than the middle. Porcelain shrinks a lot as it's fired. The edges shrink before the center and the weakest part will crack to relieve the tension around the edge. I've tried a lot to prevent this and drying the slab between to pieces of drywall helps to relieve any bound in stress during the drying process but it'll still crack on occasion even if I slow the bisque or glaze fire way down to 2 day ramp up.
You need to make your slabs with paper clay. I don't recommend rolling out or throwing them conventionally, either. I'd mix up a batch of pclay slip, pour it out on a big, extremely flat plaster bat, and screed it to the thickness you want with 2 shims and a metal rule. Then, take a rubber rib or squeegee to it as it starts to firm up to get the surface you desire. When you dry it between drywall boards, never lift the slab by hand. Only flip it onto the board a la large thrown platter. It must never know anything but flatness. Hell, I wouldn't even cut it to size until bone dry with shears, lest that introduce any warp.
Firing speed seems good, but I hope you're brushing some alumina hydrate wax on the back, or liberally dusting the shelf with alumina. Those bitches gotta slide. Don't fuck with kiln wash. Kiln wash is gay, and for noobs. Investing in one advancer (silicon carbide) shelf for firing your super flat shit would be a good idea. Never, ever let a drop of water touch those shelves. As far as eliminating the uneven edge heating issue, I would dam up a low wall up ifb's around the slabs. This does work, both for ceramic slabs, and glass plates.
I can look up some pulp to slip ratios and fiber lengths for ultra thin slabs if you give a shit.
It's what the slabs are made of. The 2ft by 2ft surface area is just an extreme, flat surface area for a clay with porcelain's shrink rate. it's great for sculpture. You can do a lot and even bond completely bone dry pieces of paper clay together with a little paper clay slip. It's just bulks at making very large slabs. Believe me, I've done now 10 years of research and experimentation. I've asked master potters from all over the US and Japan and they all tell me to use smaller slabs. One recommended getting a hydraulic press and try compressing leather hard clay into slabs with tons of pressure rather than paddling and rolling. I've yet to try that because of the prohibitive cost and my lack of welding skill to modify a press.
I tried going through my old notes but I can't find the book with my old notes but I can't find my old experimentations. All I remember is that the colorants are iron oxide, manganese dioxide and cobalt carbonate.
I think I was using cmc gum as the binder. I found that the recipes that require firing were rather worthless as they were too powdery for long, multiday drawings as they smudge too easily.
So you have or have not made a slab by screeding pclay slip? Are you dusting it with cornstarch to allow it to slide during wet to dry shrinkage? Have you rolled out draft-blocking coils to surround the slab between the drywall boards? Have you put weights on the boards? Do you flip the boards? What is the maturing temperature of your clay? What are you firing it to? Were all of these slabs made by rolling plastic clay? Tell me precisely what this body is, and why you are using it. Nothing is impossible. I do "impossible" things with clay.
I'm not against it and I've tried it and it works well enough but not any better than paper clay. It worked best as as letting get leather hard and then moving it to a slab of drywall and covering it to another peice of drywall and taping it around the edges. Letting it dry on a plaster wedging table still causes uneven drying. But letting regular old paper clay dry between drywall produces the same result.
The problem that I've still encountered is the uneven heating in the kiln as the edges head far faster than the center. The problem is when it goes through the quartz inversion it's expanding unevenly and then at around cone 4 when it starts to shrink it shrinks unevenly. I've tried a lot to counter this but will little success. very slow fires just cause the temp to go up and down as the temperature in the kiln isn't completely even and the temperature is monitored at only one point in the center of the kiln. I tried firing it on top of kaowool with a layer of wool on top and tucked over the edges think that the insulating layers would cause more even heating but it doesn't seem to. I've tried placing kiln posts around the edge of the slabs so it's not in a line of sight of the elements but that actually has worse results because I think the top is still heating faster bottom. I've then tried firing on little ballmill marbles so the bottom would heat faster than the top but that yeilds the same results as just firing it normally. I've tried firing them standing straight up between kiln bricks but slumping becomes a problem and it tends to crack between the bricks because of uneven heating.
I'm not trying to just be a negative nancy I've just done a lot of work and survivability still sits around 65 percent.
I see why a lot of people I've talked to have laughed when I asked for advice.
I am compelled by difficult problems. Answer my questions about what clay you're using, and why. What I'm specifically after is what is the look and feel of the finished piece you want. What dimensions, what physical properties?
I'm using a grolleg paper clay for it's high translucency. The clay has a glow beneath the drawing once it's been fired to maturity. I have better luck with just plain white stoneware paper clay and use it but I still temp fate with the grolleg. I'm using slabs that are 24 inches by 24 inches square which is about the dimension of my kiln. Once mid fired it's about 22 inch x 22 inches. The next thing I'm going to try is wedges that go from the upper corner to the lower corner out of soft brick and try firing diagonally but I'm probably go to burn out my elements doing that with the hot spots it'll create.
Ok, I understand. What are you using for the drawings, and at what stage are putting them on the slabs? I had a couple ideas, but they're dependent on your drawing process.
Grolleg paper clay rolled into slabs? If yes, are you doing it by hand, or are you using a slab roller?
Not sure you're going to burn out the elements firing a shelf diagonally, so long as you're not resting anything against an element. Do I have that right? I'd just be sure the bottom of the shelf rests at the floor of the side with the thermocouple, so it's reading the open space. The kiln doesn't give a shit if it's a really open stack. That said, I don't see how it'll work any better than flat to reduce warpage.
I'm doing a combination a paddling by hand a rolling by hand. I bisque to 2000 degrees F because the clay is too soft at 1800 F and the underglaze pencils actually start to etch into the clay when drawing.
Firing diagonally will heat the bottom as well as the top more evenly. Or at least it's with a shot. I'm experimenting with the idea that uneven too and bottom heating may cause some of the cracking.
Not ideal, but you do what you gotta do.
Anyway, I'm going to assume you're using a cone 6 body, and you're firing it to cone 6 after the bisque firing.
It struck me that warpage is not your problem so much as the cracking. when during the firing do you believe the edges sometimes crack? Are you absolutely certain that the porcelain isn't sticking just a little bit and not sliding as it shrinks? Or that there isn't a little bit of jaggedness where a crack begins? Are you resting the slabs on a bed of alumina hydrate?
As for warpage? Ha, fire hotter. Fire to cone 7. Or cone 8. Test it out on a slab you haven't invested surface drawing on. If you fire it hot enough, it will fire flat. It will flatten out. But you must have a perfectly flat non-stick surface. I'd strap on a respirator, lay down a 1/8" bed of aluminda hydrate powder, skreed perfectly flat with shims, and put the slab on that. It can curl up all it wants, but it will lay back down fired hotter, and it will not stick.
I'm skeptical about the cause of your cracks being solely the effect of the uneven heat distribution on the upward ramp, but I'm not in the mood to write a long ass speech about why. I honestly do think the root cause is in the condition of the raw edges and possible sticking. The heat is only the exasperating factor. But do try firing hotter.
No, I've decided why you're getting cracks. Your slabs are not perfectly flat to begin with at bone dry. Or they curl up from clay memory from the hand rolling, or the uneven thickness. then they curl up a tiny bit more as the chemically bonded water fires out, and they crack under their own weight. How to address this?
I cut the drywall to the approximate dimensions of the slab and tape the edges completel and rest it on 3 wood rails.I have a fan going to keep air circulating and I flip the board every day. Any more when they're wet you start to deform the slab. The slabs are perfectly flat and I mean perfectly. They're I've run a metal yard stick over it and it's completely uniform. Uneven drying was the first thing I tried to solve and it helped a lot. The other thing that helped was making them very thin, like 1/8th an inch thick. This helps with the uneven heating from top to bottom as well as the exterior drying before the interior.
also they're completely uniform in thickness. Also I'm going to try an old sculpting trick trick next. I'm going prick a million holes in the back like I used to do with my life sized figurative sculptures. This allows the peice to survive more flexing when drying an firing. I might even trying finding a honey comb texture that I can roll into the back which might work better. I just hope that at mid fire the pattern won't be visible in the front of the piece due to the translucency of the porcelain.
Nah, the pinprick thing is to give accidental air pockets/excessively thick areas a steam pressure escape route so they don't blow out in an uncontrolled way and ruin the piece. Damage is mitigated to a tiny pinhole. Honeycomb texture is usually used on the reverse of thick glass to relieve annealing stresses, and to lighten it. For architectural ceramics, it will give strength and reduce weight, but it's not going to help much here on such a lightweight scale.
I believe you that your slabs are flat when bone dry. I wouldn't dry them so quickly, but I'm glad you are able to.
So they're still curling up in the kiln. Why? There are only two possibilities: clay memory from the rolling, and uneven heating. Well, actually... bone dry paper clay flexes a little bit. There's an off chance they're getting bent ever so slightly during the loading. But, hey, before I go any further, have you tested the flatness of the slabs after the bisque firing? This would rule out the bending during loading.
Also, I am getting disappointed in you that you have not acknowledged my solution of over firing by 1 to 2 cones in the final firing. This is your warpage solution. Fucker can do al the curling up it wants, but at cone 7-8 it will lay back down, cracks or not.
Meanwhile, I'm thinking that the way to stop the curling in the first place is to weigh down the corners or edges with slices of softbrick. The bricks can just go for a 2" ride with the piece as it slides across the alumina substrate.
holes do that also but they can also allow for greater degree of flexing during firing before it will crack. If you look at the holes through a microscope after firing they'll be a little flattened. They can relieve some stress when the piece warping. This is how it also helps sculptures that have uneven thickness survive the fire process.
Guys which book is the best to learn clay modeling?
Are these recommended?
What is best book on the subject you have found?
Interesting. I'm going to consult some nerds. It is logical that a tubular micro-lattice structure would do this during the distortions of shrinkage. I have used small circular holes drilled at the ends of hairline cracks as a stopgap measure. However, if we were to take this concept further... paper fibers also introduce this tubular lattice structure. Would it not be advantageous, as well as more attractive to the surface to simply add more (and/or) longer fibers into the clay recipe?
from what I understand that's how paperclay works. Akio Takamori actually puts small strips of fishing line in his clay bodies for similar reasons. He prefers it to paper clay because p-clay isn't particularly plastic while the nylon thread clay is.
is there anything like... a list of hand positions on the wheel? I took a year off between my first semester and second semester of ceramics and i can't make a 6 inch cylinder to save my life right now. my hands are especially confused when it comes to raising the wall. any help?
Where do you find your cylinders are going wrong? How do you usually hold your hands? I usually encourage people to start by keeping both hands at 3 o'clock, left hand middle and index fingers slightly curled, the pressure being put on the pads/sides of the fingertips with the left forearm as close to vertical as possible with the elbow at 90º. The right hand's fingers curled into a C, pressure on the fingertips of the middle/index/ring fingers about 1/2 cm below the inside fingers. If you take your left thumb and press it against the heel of your right palm, with your left elbow raised up and make a little clamp with both hands, that's pretty close to what's most effective for short cylinders. Just remember to keep your upper body bent forward, and leaning to the right-hand side of the wheel so you can keep your eyes on your outside hands. After you get comfortable again pulling with your hands bridged together, practice keeping your fingertips opposite each other without bridging the hands via left thumb.
If you're not getting any height, your fingers are not opposite each other, or you're not squeezing hard enough. You'll know when you're squeezing too hard, because you'll torque the wall, or rip it in half. If you're getting bowls, you're spinning too fast, or not keeping your eye on the right hand. The right hand dominates. It lifts and pushes toward the center of the wheel to overcome the centrifugal forces.
If you tell me what's happening, I'll tell you what you're doing wrong. Everybody eventually develops a slightly unique grip, but the physics are always the same.
Couldn´t find it on ebay
Bought these 3 instead.
Once they reach my country I will scan them and send them to the book thread guy.
Does anyone here on ic knows how can I reach him/her?
His technical ability is mind boggling but his work is just simple third order simulacra and the most boring take on the subject. Like the matrix or the Truman Show, he seems to take the hypothesis of simulation as irrefutable fact and turns around and presents it as simply as a visible phantasm.