Elu Ceramics Posted May 8, 2017 Report Share Posted May 8, 2017 Hi there, can anyone help, I am currently working with a new underglaze which i paint on with a brush, then dip glaze after, (no hardening on fire usually needed) I am getting these indented lines which look like brush hairs on the finished product. surely the brush hair would be burned off, if so why is it leaving a line where the hair was? And why dont i have this issue with other underglazes? does anyone else's paintbrushes leave behind hairs? thanks. Candice. Link to comment Share on other sites More sharing options...
LeeU Posted May 8, 2017 Report Share Posted May 8, 2017 A picture might help if you could post one. Brushes may occasionally leave hairs when they are old or (usually) of poor quality to begin with, but I've never seen any evidence after firing. Link to comment Share on other sites More sharing options...
oldlady Posted May 9, 2017 Report Share Posted May 9, 2017 yes, i have some very old brushes and made the mistake of keeping them where bright sunlight can reach them for a long time. the last time i used one of the hake brushes, it left so much hair on the pot that there were many, many white lines in the slip after firing. the hair was stuck in the slip and was burned off. then i realized it was from the 1980s. duh............. Link to comment Share on other sites More sharing options...
Elu Ceramics Posted May 9, 2017 Author Report Share Posted May 9, 2017 thanks for your reply, I attached two photos, hope you can see them, I have always used the brushes and never had these problems before, i imagine they just get burned up? so was wondering if it could be the new underglaze? Link to comment Share on other sites More sharing options...
bciskepottery Posted May 9, 2017 Report Share Posted May 9, 2017 Glaze compression. If the brush hairs were on the surface of the glaze, they would likely burn off during firing. But, they are trapped between the underglaze and your clear glaze. So, even as the hair burns out, the glaze shrinks/compresses during firing to the shape/texture of what is below it . . . Could be the brush is getting old. Check for loose brush hairs before underglazing. Check for lost hairs before applying the glaze. Or, apply the underglaze to greenware and let the bisque burn out any hairs. Link to comment Share on other sites More sharing options...
Elu Ceramics Posted May 11, 2017 Author Report Share Posted May 11, 2017 thanks for the info, is it possible to apply the underglaze to greenware? thought it may get a bit heavy and collapse? never done it before but would like to give it a try. thank you! Link to comment Share on other sites More sharing options...
oldlady Posted May 11, 2017 Report Share Posted May 11, 2017 yes, there is another south african potter here on the forum. you should talk to each other, she has been through a lot of the kinds of questions you have now. i think her name here is Andrea B. she lives in Johannesburg. i thought she was in cape town, but maybe you can share ideas and possibly shipping charges if you need things not available locally. Link to comment Share on other sites More sharing options...
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