clay lover Posted October 23, 2014 Report Share Posted October 23, 2014 I'm trying to replicate a piece I saw done in a you tube video, and the presenter was using low fire clay. I work in stone ware and it seemed to me watching that the low fire was really rubbery, and he worked it really thin. When I rolled out slabs with my cone 6 clay I had a lot of trouble folding and stretching the clay like the presenter did. I do a good bit of hand building, but not this folding process. Is low fire clay more bendy? Link to comment Share on other sites More sharing options...
bciskepottery Posted October 23, 2014 Report Share Posted October 23, 2014 The low fire clay was probably grogless; your stoneware clay likely has grog. So, you are comparing apples and oranges in terms of clay bodies. You can find stonewares with no grog which should make the folding process more comparable. Another factor is keeping the clay moist while being manipulated. The will be some differences due to firing temperatures. Low fire shrinks less and will likely hold the shape more; stoneware fires higher, shrinks more, and could result in some distortion/warping -- hard to tell without seeing the form in question. Link to comment Share on other sites More sharing options...
oldlady Posted October 23, 2014 Report Share Posted October 23, 2014 the other problem could be that you are folding the clay when it is too thick. how thick is your slab? how dry is it when you are ready to fold it? have you left it sitting while working on something else for "just a minute"? it takes a while to figure out this stuff. try several thicknesses to achieve what you want as far as shape and see which will give enough to fold without tearing or be too thick to fold at all. Link to comment Share on other sites More sharing options...
neilestrick Posted October 24, 2014 Report Share Posted October 24, 2014 The temperature range of the clay is a non-issue. It all depends on what's in the clay body. Link to comment Share on other sites More sharing options...
Chris Campbell Posted October 24, 2014 Report Share Posted October 24, 2014 I agree with Neil ... It's what is in the clay. You want a very forgiving elastic clay for this type of building. A short clay of any type is going to crack. Ask your supplier for the most forgiving, elastic and versatile clay body they have. Link to comment Share on other sites More sharing options...
neilestrick Posted October 24, 2014 Report Share Posted October 24, 2014 One of the problems some people have hand building with low fire white clays is that they dry out quickly due to the fact that they have a relatively low percentage of clay in them compared to most clay bodies. I hear this complaint from teachers all the time. And they really aren't happy with the Texas talc everyone is using now. Link to comment Share on other sites More sharing options...
clay lover Posted October 24, 2014 Author Report Share Posted October 24, 2014 Chris, is what you are describing what a good throwing body is? More elastic? I chose the best throwing body I have, but I don't know about the grog. It is Redstone, From Highwater. very happy to stand up tall and get thin. Link to comment Share on other sites More sharing options...
bciskepottery Posted October 24, 2014 Report Share Posted October 24, 2014 I chose the best throwing body I have, but I don't know about the grog. It is Redstone, From Highwater. very happy to stand up tall and get thin. Highwater's description of Redstone: "This is a rich, reddish brown body with a lot of character, warmth and excellent working properties. Use for hand & wheel work. 6% fine kyanite." So, it may not be the smoothest body. Kyanite has good thermal shock properties. Link to comment Share on other sites More sharing options...
Benzine Posted October 24, 2014 Report Share Posted October 24, 2014 Neil, I've been using a low fire white, in my class, for ten years, and haven't had a problem with it. It dries about how I need it. Sometimes, I do wish it would dry a bit faster. That way I wouldn't have students twiddling their thumbs, leading me to ask what they are doing. Their answer, "Well my slabs have to dry..." It helps if you imagine a stereotypical teenage voice, when reading that phrase. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted October 24, 2014 Report Share Posted October 24, 2014 Neil is right about the temperature being irrelevant to the properties of the clay. That is like asking if a red sweater is warmer than a blue one. Hand building really doesn't address your needs either. Read the properties of the clays from your supplier. Call their customer support and talk to a tech. and tell them what you are looking for in a ^6 clay. Suppliers are all over the country. Find one close to you to work with. Marcia Link to comment Share on other sites More sharing options...
clay lover Posted October 24, 2014 Author Report Share Posted October 24, 2014 I will check the properties of the clays I have on hand, and have another go at it with the clay that has no words like grog, or tooth, or mulite or kyanite. see how it goes. This infor explains how the presenter was so casual about his joining process. If there is little shrinkage, there is little stress on joining, right? Other properties of low fire are.......? as different from stoneware. Link to comment Share on other sites More sharing options...
clay lover Posted October 24, 2014 Author Report Share Posted October 24, 2014 OK, went to Highwater and Tucker clay info sites. I have some Tucker Mid Smooth Stone that says 'no grog or fireclay" but has 14.5% shrinkage. Of the Highwater clays I have, Ellen Buff says "3% mullite,12% shrinkage ", Brownstone has "3% fine grog" with 11% shrinkage and the Redstone I used lists " 6% kyanite with 10% shrinkage." No info is given on grit size. Is kyanite more /less an issue for me than mullite? From this, I am assuming that as far as stoneware goes, the less grog, the more shrinkage. So shrinkage will work against me after the piece is made, but less grog will help me get it put together. Is this right? Does this info make the Tucker Mid Smooth Stone the best bet of the clays I have on hand? Link to comment Share on other sites More sharing options...
bciskepottery Posted October 24, 2014 Report Share Posted October 24, 2014 Can you post a link to the video so we can get an idea of the form and process? Link to comment Share on other sites More sharing options...
clay lover Posted October 25, 2014 Author Report Share Posted October 25, 2014 it's only a simple shallow tray form but has edges made from 3" wide strips of clay that are fastened to the side, then rolled out over the sidewall and back around to fasten again to the outside of the wall, leaving a hollow, round edging that looks like puffy fabric. On my 2nd try, I rolled the initial slab much thinner, and worked wetter with better results. I will try the lower grog clay tomorrow. perhaps 3rd time will work out the rest of the bugs. Thanks for the clay advice. Link to comment Share on other sites More sharing options...
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