missholly Posted December 14, 2010 Report Share Posted December 14, 2010 hi everyone. super duper newbie here. i have a cone 6 clay. i thought you were supposed to bisque it at cone 6. im told to bisque it at cone 05? i dont understand that. Link to comment Share on other sites More sharing options...
Seasoned Warrior Posted December 14, 2010 Report Share Posted December 14, 2010 hi everyone. super duper newbie here. i have a cone 6 clay. i thought you were supposed to bisque it at cone 6. im told to bisque it at cone 05? i dont understand that. Hi missholly: You certainly have a season-appropriate name . Welcome aboard. It has been my experience that the cone number of a clay is the point at which the clay body vitirfies. I have no idea why it was suggested that you should bisque fire it at cone 5. I've bisqued and fired at cone 6 and have been happy with the results. I am sure that if there is a reason to fire at cone 5 that someone here with more experience than I will come on and explalin. One of the things I like about this forum is that there really are highlevel expeets in just about any subject related to pottery. Regards, Charles Link to comment Share on other sites More sharing options...
Chris Campbell Posted December 14, 2010 Report Share Posted December 14, 2010 Seasoned warrior is right that the Cone range number on the clay is the temperature where it is mature or vitrifies. I was taught the reason for bisque firing at anywhere between Cone 010 and Cone 04 was to get rid of impurities and gases that could affect the outcome of your higher glaze firing. Bisque firing should be slow. A recommended temperature to bisque at is often in the clay catalog information section. However, as you will learn with pottery ... it all depends on the next thing you want to do. Not everyone bisques to the same temperature and many don't bisque fire at all. There are glaze recipes formatted to be used on dry clay then once fired. Many people once fire because they don't glaze at all Others once fire because the final product is non functional, so perfect fit is not crucial. Porcelain people fire high first, then low fire glazes. Some bisque fire at a medium rate, others swear it has to be super slow. Most bisque between Cone 04 to Cone 08 depending on how porous they want the results. The more porous the clay the more glaze it holds and if you do raku or pit firing, some will swear all those extra nooks and crannies produce more vivid results. I hope I did not over answer and just muddy the waters! Link to comment Share on other sites More sharing options...
missholly Posted December 16, 2010 Author Report Share Posted December 16, 2010 hi charles, hi chris. yes, this is my time of year! thank you so much for the responses. so, my understanding is: if the clay is a cone 6, you fire it at cone 6. im using laguna clay wc-609 (which is a cone 6) and amaco velvet underglazes. the recommended cone for the glazes is the same cone as the clay. (im hoping to once fire as much as possible) but not only did my ceramics teacher tell me to fire to a cone 05, the clay tech at laguna said so also. Link to comment Share on other sites More sharing options...
Chris Campbell Posted December 16, 2010 Report Share Posted December 16, 2010 I think you need to clarify what you are doing before we can give you a good answer. What are you planning to make with this clay? First, Velvet Underglazes are not glazes ... They are colors that can be used under glazes, thus the name. They fire successfully from Cone 05 all the way to Cone 6 and some above that to Cone 10 . You don't always need to glaze over them unless you are making functional ware. If you are only firing your Cone 6 clay to Cone 05 it will be fragile and NOT to be used for food or drink. Without a glaze it won't be a food safe surface and will seep liquid. You don't always have to fire the clay to maturity if you are making non-functional wares but if you are making dish ware you need to fire to maturity and match the glaze to the clay for a proper fit. By proper fit I mean there so be no cracks, shivers, crackles, bare spots, etc. Link to comment Share on other sites More sharing options...
missholly Posted December 16, 2010 Author Report Share Posted December 16, 2010 right now im just doing brocade art tiles. i have a kiln full of bone dry tiles painted with the velvet underglazes. i was hoping to just once fire. some will stay matte, some i will glaze. from the answer i just got from the clay tech, i should fire the underglazed tiles to a 04/05. and if i want to glaze them, would i have to glaze/fire to cone 6? or could i just underglaze/glaze in one shot and fire to 04/05? geesh i feel stupid!! i hope im not being a pain in the butt!! Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 16, 2010 Report Share Posted December 16, 2010 Read the label on the underglazes. WHat is their maturing temperature? If they go to ^6 you could once fire them with out a glaze. If you wanted to glaze them without testing how to for a once fired glaze, them bisque fire them to ^05 or so. Glaze fire them to ^6. It depends on the products temperature. Some underglazes will go to ^6 and some won't. Marcia Link to comment Share on other sites More sharing options...
Chris Campbell Posted December 17, 2010 Report Share Posted December 17, 2010 You are just new and excited to see what happens ... not stupid or a pain in the butt. Fire those tiles unglazed to Cone 05 or 06. I would not glaze any of them until you know if you even like the results. Unglazed means you can keep working on them and fire again if you are not happy. I would also make a test tile with all of your colors on it. Glaze half of it and leave the other half plain. That way you will see the results without risking all the work you put into the good tiles. If you are planning on making more tiles you might want to ask yourself why you are even using a Cone 6 clay ... There are clays that mature at lower temps. Link to comment Share on other sites More sharing options...
Seasoned Warrior Posted December 17, 2010 Report Share Posted December 17, 2010 right now im just doing brocade art tiles. i have a kiln full of bone dry tiles painted with the velvet underglazes. i was hoping to just once fire. some will stay matte, some i will glaze. from the answer i just got from the clay tech, i should fire the underglazed tiles to a 04/05. and if i want to glaze them, would i have to glaze/fire to cone 6? or could i just underglaze/glaze in one shot and fire to 04/05? geesh i feel stupid!! i hope im not being a pain in the butt!! Don't feel stupid and you certainly aren't a pain. Everyone goes through a bit of stress with any new concept. I have a philosophy with clay that others may not agree with but in my opinion it is really hard to screw up clay. I've had stuff that has come out of the so radically different than what I expected but it was always a learning experience. I belive clay is one of the most forgiving of mediums to work in. Chris suggested a test tile and I think that is a great suggestion. I like to test and I test allkinds of things. I test for shrinkage in different clays and I test glazes, I like to vary components or add components or mess with the ratiios just to see what happens, in fact it's rare that I don't have a few test coupons in almost all of my firings. One thing I have done since I was very young was to keep diaries of the things I do and list all the variables. I frequently refer to my diaries and have them cataloged so I can refer back to them. Ceramic arts are an interesting journey, relax and have fun with it! Best regarrds, Charles Link to comment Share on other sites More sharing options...
Guest Sherman Posted December 18, 2010 Report Share Posted December 18, 2010 miss holly, As others have recommended, testing is a great idea with any new endeavor in ceramics, whether your new or have been at it for years. It's just something we all get accustomed to doing on a regular basis. Chris' suggestion for testing your color and glaze combos is a really good one. One of the best reasons for bisque firing the underglazes is to set them so that they will not bleed into the glaze you apply over top. If the underglaze and glaze were both unfired and you took them both up to maturing temperature, they would have a tendency to mix a bit. If you have any nice clean edges in your designs, they could blur or become fuzzy. Test both ways, and see what works best for you. The other great reason to bisque (IMO) is to avoid potential glaze problems later when all that organic material in the clay needs to burn off. If you did not bisque fire, the only place for those gases and organics to go is through the glaze layer, which can cause pinholes and other odd bubbling defects. It's not guaranteed, of course, but it's a risk worth testing for. The sooner you embrace the idea of testing all the time, the more you'll learn, and the sooner you'll be making the work you envision. Welcome---and happy testing! Sherman Link to comment Share on other sites More sharing options...
missholly Posted December 21, 2010 Author Report Share Posted December 21, 2010 i feel soo much better now! thank you everyone SO much for all of your thoughts. i feel 100% confident about the situation, and hopefully i can fire in the next few days. this is the first art that ive fallen in love with. i cant get enough. i hope that one day ill know enough to help someone else out! thank you again!! Link to comment Share on other sites More sharing options...
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