AWPottery Posted March 2, 2014 Report Share Posted March 2, 2014 First off... thanks to everyone who has been helping me with all these naked raku questions I have been posting. Okay, so a few days ago we did our first naked raku firing.... My results posed these questions so far 1) On pots that I used white terra sig I noticed that they turned more of a gray and black instead of a white and black? Anyone have any suggestions on why this is? My thoughts were maybe because instead of using porcelain clay I used stoneware? Or perhaps I put to much newspaper in the trashcan when reducing? 2) I also did some pots with red terra sig and we fired one of them. Afterwards when I was cleaning it off, it completely wiped off the black crackle lines, basically just leaving me with the original pot of red terra sig. What could have caused this? Again this pot was stoneware, but I also fired this piece to cone 04 instead of 09 unlike the others. Or could it have something to do with the color? Thoughts? B/c if possible I would like to try firing it again if it could work. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 2, 2014 Report Share Posted March 2, 2014 what temperature was your bisque firing? Marcia Link to comment Share on other sites More sharing options...
AWPottery Posted March 2, 2014 Author Report Share Posted March 2, 2014 Marcia.... for the first pot to question one which was terra sig'd white I bisque the pot to 09 like you suggested for the second pot to question two it was bisque to 04 (the red terra sig'd one) b/c it was done b/4 I knew it was better to fire the terra sig'd pieces to a lower temp Link to comment Share on other sites More sharing options...
AWPottery Posted March 2, 2014 Author Report Share Posted March 2, 2014 Or did you mean what temp was the naked raku firing? B/c we fired that to 1500 degrees Link to comment Share on other sites More sharing options...
AWPottery Posted March 2, 2014 Author Report Share Posted March 2, 2014 Anyone? Ideas? Link to comment Share on other sites More sharing options...
ayjay Posted March 3, 2014 Report Share Posted March 3, 2014 Anyone? Ideas? I can't help much, but I doubt it's too much newspaper: when I've done it they go into a dustbin full of sawdust and shavings and get covered with more of the same before a lid goes on for about 20 minutes. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2014 Report Share Posted March 3, 2014 #2Bisque firing temperature. I wondered if the bisque was high for the terra sig. So the red sig may have sealed at 04 and not accepted the carbon. #1reading Linda and Charlie Rigg's directions, their fire their naked raku to 1450. Marcia Link to comment Share on other sites More sharing options...
PeterH Posted March 3, 2014 Report Share Posted March 3, 2014 AWPottery, Are you using one or two part slip? 1) On pots that I used white terra sig I noticed that they turned more of a gray and black instead of a white and black? Anyone have any suggestions on why this is? My thoughts were maybe because instead of using porcelain clay I used stoneware? Or perhaps I put to much newspaper in the trashcan when reducing? In my experience the grey happens when the refractory coat of a 2-part slip is too thin or porous (or the glaze not fully melting). Or the slip might be starting to peel off, so the smoke is getting under it. 2) I also did some pots with red terra sig and we fired one of them. Afterwards when I was cleaning it off, it completely wiped off the black crackle lines, basically just leaving me with the original pot of red terra sig. What could have caused this? Again this pot was stoneware, but I also fired this piece to cone 04 instead of 09 unlike the others. Or could it have something to do with the color? Thoughts? B/c if possible I would like to try firing it again if it could work. I would fire again without any slip. If the black still wipes off, then the pot or t-sig is insufficiently porous to accept smoke (if the foot of the pot has no t-sig, you can see how the body reacted). Even if you cannot use the pot for naked raku, you can still refire with glazes. If you do get a good black, you can reslip and try for naked raku again (putting the first failure down to innapropriate temperatures?). Regards, Peter Link to comment Share on other sites More sharing options...
AWPottery Posted March 3, 2014 Author Report Share Posted March 3, 2014 Peter, 1) This was a 2 part slip. It was put on fairly thick. However,, a few pieces did peel off so perhaps that could be it. 2) On this pot (the red t-sig) it is interesting what you suggested because I did put red t-sig on the body of the pot but left a small top portion w/out t-sig and it did accept the smoke so the rim of the pot is black, but on the body of the pot where it was t-sig the smoke completely came off. Link to comment Share on other sites More sharing options...
PeterH Posted March 3, 2014 Report Share Posted March 3, 2014 AWPottery, 1) This was a 2 part slip. It was put on fairly thick. However,, a few pieces did peel off so perhaps that could be it. For a 2-part slip the main purpose of the 1st layer is to stop the 2nd (glaze) layer sticking to the pot, so it doesn’t need to be too thick. A bit of food colouring in the 1st layer helps to make sure that you get full coverage coats of both layers over the entire pot. I think I've had grey "whites" with very thin pots (the smoke going though the pot from the inside). However unless you cast your pieces they are unlikely to be this thin, if they are, glaze them internally. 2) On this pot (the red t-sig) it is interesting what you suggested because I did put red t-sig on the body of the pot but left a small top portion w/out t-sig and it did accept the smoke so the rim of the pot is black, but on the body of the pot where it was t-sig the smoke completely came off. That does sound like you overfired your t-sig. Regards, Peter PS You can mix naked and glazed raku on the same pot if you separate the different areas with a thin line of copydex (a thick-ish latex glue), this leaves you with a blackish line between the regions. Remember to peel off the glue before firing. Even just naked rake + plain crackle (same glaze) looks surprisingly good. Copydex is the only way I've found to avoid trouble with the 2nd glaze layer of the naked rake touching the pot at the edge, and sticking permanently. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2014 Report Share Posted March 3, 2014 That is what I thought too.The terra sig sealed at 04 bisque. Marcia Link to comment Share on other sites More sharing options...
AWPottery Posted March 3, 2014 Author Report Share Posted March 3, 2014 Peter, thanks for answering my questions Cool tidbit about doing naked raku and regular raku together! Marcia, thanks for answering me as well. You've always been helpful. Link to comment Share on other sites More sharing options...
PeterH Posted March 4, 2014 Report Share Posted March 4, 2014 AWPottery. Copydex is the only way I've found to avoid trouble with the 2nd glaze layer of the naked rake touching the pot at the edge, and sticking permanently. Must try to engage mind before typing. I've tried things like wax resist and they didn't work. You can of course use masking tape and peel before firing. Depends if you want straight edges or a less formal effect. I've always had problems trying to get thin lines with masking tape. Regards, Peter Link to comment Share on other sites More sharing options...
AWPottery Posted March 4, 2014 Author Report Share Posted March 4, 2014 Peter- you mentioned doing naked raku and regular raku on the same pot. I like this idea, but what temp are you firing these pieces then? B/c were I take the classes they are firing the naked raku at 1500 and the raku pieces at 1800. How would this work? Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 4, 2014 Report Share Posted March 4, 2014 I use latex for peeling away images in Raku. I thin it a little. Do some more reading. David Roberts, Wally Asselbergh, Linda and Charlie Riggs, are among my favorite at this technique. http://www.mudfire.com/wally-asselberghs-workshop-20101023.htm David Roberts large piece are sanded with a diamond pad and have a wonderful feel to the surface. Marcia Link to comment Share on other sites More sharing options...
PeterH Posted March 4, 2014 Report Share Posted March 4, 2014 AWPottery, Peter- you mentioned doing naked raku and regular raku on the same pot. I like this idea, but what temp are you firing these pieces then? B/c were I take the classes they are firing the naked raku at 1500 and the raku pieces at 1800. How would this work? At the raku firings I go to they fire everything at about 1030C. So I have to formulate things for this temperature. Do you have 1800F glazes available to you (including a crackle)? Do you mix any of your own? Do you mix your own bottom-slip for the 2-part raku? Regards, Peter Link to comment Share on other sites More sharing options...
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