Helena1

@Min yes i will probably have to at least try it to see if it helps! Thanks

@Roberta12 ive also had problems with chartreuse which is an shame because I really love that color! But it’s also been happening with amethyst, turqouise, blue, orange, maroon… to mention a few. Since it’s happening so much I feel like it’s some overall problem that I don’t see. I will also try to fire higher and be more aware of the texture of the underglaze, stir it more frequently and use the gum solution when I get a hold of it. But it’s a very bad feeling not being able to pinpoint the fault! If one piece shivers I feel like more might do it as well with time @Rae Reich thank you, I will go on and try this as well. I started bisque fire higher than the glaze because I read this in a mayco spreadsheet about shivering. If I use a commercial brush on clay it’s not hard to adhere the glaze, but maybe you have a point in this is only making the bond worse because I feel like all my experiment is only leading to more shivering… some of my pieces get fired 3 times now and maybe it’s just a waste of time as well as the bonding part! @neilestrick they all fire to be mature/vitrified at a higher cone. Unfortunately my supplier don’t have much to offer for a more low fired clay. They offer earthenware without chamotte, i would prefer it with since I hand build a lot. I read somewhere that earthenware don’t really mature anyway so I thought it wouldn’t make a difference to use stoneware. I am also reluctant to earthenware because of the damage it could do to the kiln if I get it wrong :S I have seen the underglaze shiver off bisque in some pieces as well, when I was trying to apply UG in Leatherhard stage. But some of these pieces where using a commercial slip from another brand as well so that was for sure part of the problem. But it seems to be continuing still as my latest shivering piece didn’t have the engobe. I painted it white though, using the white UG from amaco, and added more colors after bisque. It probably came out to thick, but I feel like I’m not sure about this either as I feel like I have always been painting underglaze somewhat heavy since i started using them.

Hi! Thank you so much. i am making sculptural work, so it’s non functional. Here is an image showing underglaze amaco sea glass shivering off a piece fired to 1044/cone 05 and the clay used. https://www.we.no/produkt/65502114/hvit-leire-1000-1300-10kg-25-chamotte-0-0-2mm The yellow piece is also treated with amaco velvets. It’s a different clay body, https://www.we.no/produkt/65502101/snohvit-leire-1000-1280-10kg-uten-chamotte I link the clay however they might not give a lot of information, maybe there is more about them on the package. Since they can be fired up to 1300 C according to the package maybe their maturing point would be around cone 10.

Hi I have, since one year ago, gotten an extreme problem with underglaze and engobe shivering off my pieces. I don’t know how to troubleshoot the problem. I am using mainly amaco but also some spectrum underglaze, as well as mayco stroke and coat. I started off in 2021 buying amaco VUG. When the colors did not come out so vivid, I realized I need to fire lower. I used stoneware clay fired 08 for bisque and cone 1-3 for glaze. I use transparent glaze and I paint my ware after bisque. I have always sponged or painted my ware with slip made from some leftover clay from the same clay. 1 year ago, I started experimenting with adding kaolin to the slip to make it whiter. I also started firing lower, sometimes as low as 05. This is where my problem with shivering began. I was advised to drop the slip, paint only with the underglaze. I was also advised to change glaze and/or clay. I have tried 3 different white clays, and multiple transparent glazes. I am mostly firing cone 04 but was also advised to go higher. I experimented with firing bisque higher than glaze firing, which led me to starting to bisque my work higher and also making 2 bisque fires before glaze because I thought maybe this could somehow help with the shrinking. Now I am wondering if it is making things worse? I once refired one of a piece that had been glaze fired to cone 04 first up to cone 5 and noticed today the piece is shivering in edges. (I was using transparent glaze with wide ranges) Even when I went back to firing cone 1-3 like I had done before when all of this started, still some of my pieces shiver immediately after I take it out of glaze fire. One piece I tried only painting with engobe and it shivered as well. I also experienced shivering immiedately after bisque fire upon trying to paint on leather hard instead of bisque. This was however also when using a slip before so maybe it got a little bit thick with everything. I contacted amaco support advising me to use gum solution in the underglazes, as some of them were bought more than 2 years ago, I was also advised to used only distilled water which I have never done and I have mixed water directly into the jars when they seemed to be getting dry. I don’t know the outcome of the gum solution yet as I haven’t done any glaze firings. I know I might apply the underglazes a bit thick. However, I was certainly doing the same application 3 years ago and none of these pieces has shivered. I am working with ceramics a lot producing many pieces so the whole situation is very devastating for me and I don’t know what to do! Before I was doing basically everything the same and not experience shivering once, now it’s everywhere I look! Can someone help me think of something I haven’t thought of yet?