ABlanc

Thank you! Based on the error message, it might be the relays which we are checking now, or it the kiln was loaded way too bottom heavy. Elements are all good thankfully. Once we get that sorted we will just give it another go - I had just wondered if I needed to reglaze or fire differently the second time since the pieces already fired at 800 degrees for awhile, but I am just overthinking it.

The kiln gods frowned on me last night. My Cone 6 glaze firing errored out and the kiln only got up to 828F degrees before stopping and cooling back down. The pieces look fine - like unfired glazed pieces but the surface looks a little "cooked" or "toasted". Good to just fix the kiln and give it another go? Or did something happen chemistry wise to the glaze hanging out at 800F that I should take note of before refiring? Thanks in advance!

This was what I was worried would be the ultimate answer. I say that because we really want to use our low fire glaze and also have the clay fire to a buff color, not white.

Flat with sand and right side up, meaning the back with the "walls" is on the shelf.

Meaning is it or meaning it should be? These are hand formed out of slabs.

Here are some pics of another similar piece with post bisque firing crack that runs on the front and then continuously up the back (I marked alongside in yellow so you can see better) Just the wrong clay for the job perhaps?

Those spirals, wow, interesting how you can really see them there. We like the crazing and the reason we are under firing is because we like the color of this clear low fire glaze paired with the creamy color of the B mix. And the B mix is just always available. We did order some with grog to test out, still waiting for it. Definitely not a toilet seat lol. It’s a wall sconce or will be. It’s about about 12 inches in length and only sits off the all about an inch. The back side “walls” are for hiding LEDs/horse hair - see pic. Those walls are slab strips cut and attached to the back. Here is pic of similar sized finished piece. Our success rate (I.e. no cracks) has been dismal with these pieces. They either crack like this or have hairline cracks after bisque.

We are doing a ramp up and down during firing - we have other work that is for sure cracking due to dunting so we added a ramp down on everything. I will check if the glaze edge is rounded over when back in the studio tomorrow. We certainly have other pieces that are just like this in design - large flat wall hanging pieces - that are coming out of bisque with hair line fractures. This particular piece didn’t appear to have any cracks after bisque though. We are not wedging this kind of flat slab work out of the bag. That is interesting to think about. One thought I had was if it was somehow due to the clay being high fire and the glaze being low fire and the mismatch of that. The clay is thus being under fired. Also B mix might just not be the best choice for large flat surfaces? Okay! Back to tearing my hair out!

Is there a doctor in the house? (Wish my first post was not about cracks!) The details: B Mix with clear glaze, no cracks after bisque on this particular piece, happened after glaze firing. However, other similar pieces in design have come out of bisque with hair line fractures. There was plenty of drying time and no visible cracking while drying with any of the pieces. Any ideas?