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Showing results for tags 'shrinkage'.
I’m interested in doing more. I had an instructor who could help me, but he’s since left the studio where I take classes, and none of the current instructors do it and can troubleshoot for me. The studio DOES still have the slip trailing and decorating slip, though, in both white stoneware (screened to remove grog) and in Porcelain. For the most part, I’ll be doing it on top of white stoneware from Standard, which has some grog in it. 13% shrinkage rate. I was watching a video of a noted potter who does a lot of it, and bought a henna application kit that she recommended, that came with 16 different tips. (The Xiem kit that the studio had seemed to be perpetually clogged or dirty, so I figured I’d better buy my own.) I imagine most of them I can’t use for slip trailing, but some of them look like the ones that came in the studio Xiem kit. She also mentioned using a deflocculant to get a smoother flow. Looking at the local pottery place website, they list Darvan # 811 and Sodium Silicate. Question 1: Which deflocculant is better for slip trailing? I know that Sodium Silicate has other decorating uses, like that surface crackle effect; but that has not been done at this studio since that first instructor left. How do you know how much deflocculant to add? Someone told me also that it goes bad quickly. Do deflocculants have any other uses? Question 2: If I do porcelain slip trailing on top of white stoneware, do I need to worry about different shrinkage rates? Or should I stick with using white stoneware slip on top of white stoneware? The studio white stoneware is more of a creamy color rather than white, so I thought the porcelain might show up better under a glaze. They are all within one % point of each other. I don’t know the porcelain # offhand, but I can find out. I also use Standard 266 Dark Brown, shrinkage rate 12.5%, which I’m testing applying porcelain slip onto in layers with a brush, then smoothing with a rib, to get certain glaze colors to (hopefully) work out better. I’ve tried white stoneware slip on this, but I’m finding it harder to get it smooth. Maybe deflocculant is something I should add to the slip for this use as well. Thanks for your help!
I search on the forum but did not find an answer to this. It possible to brush porcelain slip on white stoneware (on leather hard, like Hakeme, but covering the body completely), or would the shrinkage difference cause the porcelain to flake off? Thanks a lot! Lucia
Hi ...... Have been working on a porcelain hand built box I now just have to attach the top piece But whilst working the piece has shrunk considerably Not sure how to continue Do I cut the top piece to fit the shrinkage Or leave as is and then sand down Thank you Nicky