indianlotus

Thank you, thats good to know! Do you think an immersion blender would work instead of using a sieve? And candling /slow bisque?

Thanks! Yes the plaster was atleast 5 years old, and despite leaving it for weeks in the summer to cure, it's still very soft and i can scratch bits off with a fingernail easily. I found some chips on the edges of the bat so i'm sure it was plaster that got into the clay. I have about 4 bags of reclaimed clay that could be contaminated and I don't want to use this to make anything important in case of pop outs. I've heard it's unlikely that they would cause explosions in the kiln but rather just cracks and chips after the piece has been fired, sometimes after months even? I've also heard that if the plaster specs are small enough it won't cause a problem, and thought about putting the slaked clay through an 80 mesh sieve before reclaiming? Would using an immersion blender also work in the same way? I'll put the soft plaster bat inside of a pillowcase until I have chance to make a better one. I'm thinking i'll just use the reclaimed clay as an excuse to make myself something, and for test tiles and bisque moulds.

Thanks for your reply. Could old plaster be the cause of this? I borrowed it from a potter friend but she said it was about 5 years old. I'm also worried about all my reclaimed clay, is there a way to remove the plaster from the reclaim? If i slake it down and use a fine mesh sieve?

Hello I hope someone might be able to help with this: I've been using a plaster bat to reclaim clay and when I flip the clay over there are some tiny specs of plaster stuck to the clay. I scrape these off and dispose of them. But I am really worried now that my clay might be contaminated with plaster. I was trimming a pot earlier, and came across a small hard white lump maybe 3x3mm. I poked it out and disposed of this and finished the pot. Is it possible this could be anything else or is it likely to be plaster? I never saw any pieces of plaster this big stuck to the clay after reclaiming on the bat. I'm unsure what to do about my recent batch of pots, whether to fire them or not, and what to do about the reclaim. And going forward if it's worth removing plaster from the studio, or if it's likely that my plaster bat just didn't set right (it was a few years old potters plaster)? Many thanks!