Yeah, the yarn burns away. And yes, I had to glaze it, it was earthenware and very fragile. I did do a knitting porcelain square as well, which I left unglazed. Still very fragile, but more structural integrity than the earthenware. I'd like to try the hyperbolic growth in porcelain, too, but I figured it was better to stick with earthenware for the first attempt. It's a complicated enough shape as is without trying to factor in the greater warping that'd happen with porcelain. <_<
It's just amazing! I wanna try it and I will. So you firing twice? Firstly in biscuit and secondly to glaze it, or you firing at once? Also does it have matter what kind of yarn do you use? And did you make small trips so the hot air can go , or it's not necessary? Lot of questions, but I wanna make it good..
Yeah, I fired twice. First was one was pretty slow - I ramped to 100 Celsius at 10 degrees inc per hour, and the let it soak at that temp for an hour, just to be sure that everything in the middle of the 'sculpture' was dry. Then ramped to 200 degrees at 30 degrees inc per hour, then to 600 celsius at 70 degrees per hour (at this point you might get quite a lot of smoke coming out <_<) and then fast-ramped up to 1100. I used a cheap, crappy acrylic yarn, because wool is way more expensive, but I guess if you can afford it wool is preferable. Acrylic yarn will let off a lot of nasty black smoke, and stink the place out. I crocheted the growth quite loosely with a hook larger than was recommended for that yarn thickness, so there were lots of holes for the hot air to circulate.
Also: hyperbolic growths eat up a lot of yarn, and have a massive surface area, so they'll soak up a lot of slip, too. It makes them quite heavy. When I dipped other knitted shapes in slip I had no problem at all with smoke coming out of the kiln, but with the hyperbolic shape smoke was pouring out the top quite alarmingly. I presume this is just because the hyperbolic shape just uses so much more yarn.
Thank you very much for that good explanation! I definitely going to use your method to create something. I am going to take all your advices and suggestions. Thanks again and looking forward to see new art from you! Good luck!