Noodles Posted January 17, 2021 Report Share Posted January 17, 2021 Hello, I just want a bit of a sanity check here on what might be the issue. These are hand formed pieces and I am painting them with slip on greenware, then bisque firing. After that the usual glaze and fire. Hansen 20 x 5 is the clear. These little cracks don’t appear after bisque, just after glaze firing, my guess is something is happening between the slip during glaze firing but I will let you all advise ..... attached are pics of a few pieces, the third pic shows where I was able to pick off a piece of the clear. https://www.dropbox.com/s/hx5wsnrw8so6zo8/Photo Jan 17%2C 1 35 34 PM.jpg?dl=0 https://www.dropbox.com/s/quvsgt88tbevuer/Photo Jan 17%2C 1 36 11 PM.jpg?dl=0 https://www.dropbox.com/s/nz304m033abtjws/Photo Jan 17%2C 1 53 56 PM.jpg?dl=0 Link to comment Share on other sites More sharing options...
Mark C. Posted January 17, 2021 Report Share Posted January 17, 2021 The 1st two photos appear to be in the main clay body not the slip layer-the middle photo shot is a classic non compression crack in bottom.I think the photos 1 &2 are clay body compression issues The last shot maybe a slip issue as it looks like it jumped off at some point Link to comment Share on other sites More sharing options...
liambesaw Posted January 17, 2021 Report Share Posted January 17, 2021 Looks like your slip, glaze and clay body all have a fit issue. Address one at a time. What slip are you using and what clay body. Hansen 20x5 is fairly high expansion, so should not shiver on anything. Link to comment Share on other sites More sharing options...
Noodles Posted January 17, 2021 Author Report Share Posted January 17, 2021 Ok, would uneven drying also be a possibility versus compression? The body is G-Mix 6 from Georgies.com, the slip was 35 Silica/30 EPK/35 Ball(Hickory). Thanks! Link to comment Share on other sites More sharing options...
Min Posted January 18, 2021 Report Share Posted January 18, 2021 18 minutes ago, Noodles said: the slip was 35 Silica/30 EPK/35 Ball(Hickory) Need to have some flux in the slip. Silica, kaolin and ball clay alone isn't going to work. Link to comment Share on other sites More sharing options...
liambesaw Posted January 18, 2021 Report Share Posted January 18, 2021 Ding ding ding! That slip has no way of attaching itself to cone 6 clay. Think of it as a loosely fitting glove on your clay. Link to comment Share on other sites More sharing options...
Noodles Posted January 18, 2021 Author Report Share Posted January 18, 2021 Ahhh ok...silly me :p I got that recipe when researching doing dipped Buncheong slips......thanks guys! Link to comment Share on other sites More sharing options...
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