Bernardita Cossio
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Bernardita Cossio reacted to PeterH in Warped rims on my porcelain sculptures
Yes, but it may introduce more problems than it solves.
To my untutored eye it looks like firing with a sitter would probably solve your slumping issues.
... but would introduce glazing issues.
The classic bone china solution uses a supported high-fire bisque and an unsupported lower-fire glaze, which creates its own problems.
Bone China https://digitalfire.com/glossary/bone+china
The process is completely different than what a potter would do: Bisque fire, glaze, high fire. Bone china is bisque fired to high fire and then glazed at a very low temperature. Since the porcelain has zero porosity, getting a glaze to stick and dry on it is not easy, the process needed goes well beyond what a normal potter would be willing to do.
PS
Balancing slumping and decoration has a long history. Robert Tichane expressed his surprise when he finally realised that the ancient Chinese cup he regularly drank from had a guilded rim to disguise the lack of glaze on the rim (a result of firing the cup rim-down to minimise slumping).
I'm having difficulty visualising your "handmade leather molds". I assume that they are semi-flexible press-moulds, but am unsure how you extract the bowl from the mould.
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Bernardita Cossio reacted to Min in Warped rims on my porcelain sculptures
The concave then convex side design might also be contributing to it being pulled out of round.
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Bernardita Cossio reacted to Rae Reich in Warped rims on my porcelain sculptures
A thicker rim will hold its shape better, if you can work that into the design/construction.
Q: is it strictly necessary to have a perfectly round rim? The intriguing soft appearance of your sculpture does not, to me, require a perfectly circular rim.
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Bernardita Cossio got a reaction from Rae Reich in Warped rims on my porcelain sculptures
Hi everyone!
I have been struggling with warping rims on my porcelain pieces. I was wondering if you could give me some advice on this matter. To provide some context, I make porcelain pieces using handmade leather molds. The challenge I am facing is keeping the rim in a circular shape, as it warps during the glaze firing process. I am considering firing the pieces at cone 6 to minimize the warping. However, I am also concerned that firing them upside down could cause the body's weight to bend the walls.
Do you have any suggestions or methods I could use to avoid this issue?
