Kelsey Sowell Posted September 3, 2023 Report Share Posted September 3, 2023 Hello all! Newbie potter here. I've had some pieces sitting in damp boxes for... many months now! And while a few pieces have the requisite mold, my pieces thrown with local porcelain, Clay Art Center Mac 6, are growing this strange flaky crust. Does anyone know what this could be? Will it be a problem after bisque firing? Can I wipe it off and still use underglaze before firing? Thanks so much! Quote Link to comment Share on other sites More sharing options...
Min Posted September 4, 2023 Report Share Posted September 4, 2023 Hi Kelsey and welcome to the forum! I'ld ask the clay manager at Tacoma Clay Art Center about this. I'll pm you her email address, she might be able to help. Let us know if she can explain it, it's interesting. Kelsey Sowell and Roberta12 2 Quote Link to comment Share on other sites More sharing options...
Kelsey Sowell Posted September 4, 2023 Author Report Share Posted September 4, 2023 Great suggestion! They're so smart and knowledgeable at CAC, don't know why I didn't think to ask them! Quote Link to comment Share on other sites More sharing options...
Jeff Longtin Posted September 4, 2023 Report Share Posted September 4, 2023 Oddly, this looks like the kind of flakes you sometime see on old plaster molds used in slip casting. I wonder if a deflocculant type of substance, barium, soda ash, or sodium silicate, got mixed into this clay body by mistake? Callie Beller Diesel and Kelsey Sowell 2 Quote Link to comment Share on other sites More sharing options...
neilestrick Posted September 5, 2023 Report Share Posted September 5, 2023 Could be solubles coming out since it has sat for so long. Callie Beller Diesel and Kelsey Sowell 2 Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 5, 2023 Report Share Posted September 5, 2023 Assuming the damp box started out with water in it, it could simply be a magnified form of efflorescence of some soluble salt as the water seeped into the pot and then evaporated from it.. Kelsey Sowell 1 Quote Link to comment Share on other sites More sharing options...
Min Posted September 5, 2023 Report Share Posted September 5, 2023 I recall an issue about 15 years ago that some friends had with clay from CAC, turned out it was from the water used in the clay production. Maybe it's this again? Kelsey Sowell 1 Quote Link to comment Share on other sites More sharing options...
Kelsey Sowell Posted October 17, 2023 Author Report Share Posted October 17, 2023 On 9/4/2023 at 4:36 PM, Jeff Longtin said: Oddly, this looks like the kind of flakes you sometime see on old plaster molds used in slip casting. I wonder if a deflocculant type of substance, barium, soda ash, or sodium silicate, got mixed into this clay body by mistake? Oh interesting. I absolutely need to give CAC a call and see if they've had any other strangeness with their Mac 6. Thank you! Quote Link to comment Share on other sites More sharing options...
Kelsey Sowell Posted October 17, 2023 Author Report Share Posted October 17, 2023 On 9/5/2023 at 9:41 AM, Min said: I recall an issue about 15 years ago that some friends had with clay from CAC, turned out it was from the water used in the clay production. Maybe it's this again? Oh wow really? Do you happen to know any other details regarding the water issue? Thank you! Quote Link to comment Share on other sites More sharing options...
Min Posted October 17, 2023 Report Share Posted October 17, 2023 16 hours ago, Kelsey Sowell said: Oh wow really? Do you happen to know any other details regarding the water issue? Thank you! Don't know how long the current clay tech has been there, she might know what happened. CAC is under different ownership since this happened so not sure if the current owner, Quinn, would know either. All I heard was it was put down to being the water. Quote Link to comment Share on other sites More sharing options...
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