Interesting pot damage from silicon carbide removal?
Posted: Fri Jan 20, 2023 11:52 pm
These images are from a fully handmade modern pot sold as xiaomeiyao zhuni which I recently received and returned prior to use due to the depicted damage.
Apparently this was caused by the silicon carbide paste they commonly apply to the rim of the pot to prevent the lid from sticking during firing, which may have gotten moist in this case and thus stuck to the clay in this area, and then a bit of clay was taken off the pot when they removed this anti stick compound after firing.
I am surprised that the above mishap, if this extremely strong moisture bonding is a plausible cause, would take off such a thin surface layer and reveal such a porous layer of a different colour and texture underneath. I was able to scratch it a bit dusty with a tooth pick. The provided explanation for the difference in appearance is the temperature variation between the surface layer and the clay underneath.
The first thing I noticed when opening the pot was that it had tiny glitter particles inside, which I have never before seen in a pot, and which came from the exposed section that would also sparkle in the light due to these embedded particles. I am not sure if this could be a common mineral in the clay, however, the sparkles were far more frequent and smaller than the usual mica spots visible on the clay surface here and there. The clay on the pot exterior was a fine mesh with very few mica spots of the usual appearance. The ring of the pot was in line with expectations for the clay type and wall thickness.
Here is a shot of the inside out of the sunlight (glitter washed out already) as a reference.
Since I don't have any chipped or broken xiaomeiyao pots, I have not personally seen freshly exposed post firing inside layers of this type of pot. I assumed the clay to be vitrified evenly, perhaps with a darker colour due to a lack of oxygen, but not to be as light and porous as this.
Has anyone come across such a defect, or can provide more insight?
Apparently this was caused by the silicon carbide paste they commonly apply to the rim of the pot to prevent the lid from sticking during firing, which may have gotten moist in this case and thus stuck to the clay in this area, and then a bit of clay was taken off the pot when they removed this anti stick compound after firing.
I am surprised that the above mishap, if this extremely strong moisture bonding is a plausible cause, would take off such a thin surface layer and reveal such a porous layer of a different colour and texture underneath. I was able to scratch it a bit dusty with a tooth pick. The provided explanation for the difference in appearance is the temperature variation between the surface layer and the clay underneath.
The first thing I noticed when opening the pot was that it had tiny glitter particles inside, which I have never before seen in a pot, and which came from the exposed section that would also sparkle in the light due to these embedded particles. I am not sure if this could be a common mineral in the clay, however, the sparkles were far more frequent and smaller than the usual mica spots visible on the clay surface here and there. The clay on the pot exterior was a fine mesh with very few mica spots of the usual appearance. The ring of the pot was in line with expectations for the clay type and wall thickness.
Here is a shot of the inside out of the sunlight (glitter washed out already) as a reference.
Since I don't have any chipped or broken xiaomeiyao pots, I have not personally seen freshly exposed post firing inside layers of this type of pot. I assumed the clay to be vitrified evenly, perhaps with a darker colour due to a lack of oxygen, but not to be as light and porous as this.
Has anyone come across such a defect, or can provide more insight?