April 16, 2007

Crying over Burnt Cookies

Not so great of a weekend here. Well, the weekend was ok, but one event put a grumpy cloud over it anyway. I had a kiln misfire and the contents were way over fired. It is several days worth of work lost, as the items are pretty much destroyed and unusable.

Above is a picture of some of the contents. This was a bisque kiln, so it was only intended to go to about cone 04 (about 1900 F) But something happened with the cone (I think one of the cookie ornaments exploded and made the kilnsitter stick) and the kiln never shut off on its own. Today I am regretting not having a timer on my kiln, and also being careless in not manually checking that the kiln shut off when I knew it should have. I went to bed with it on...bad!

So anyway, in the picture above you can see one of the terra cotta bowls that I fire my bisque in on the left. And in the center, there is the same type of bowl after the misfire. It is totally an oozy melted mess, and that shelf is probably ruined. There was also a second bowl full of beads that is ruined too. Also you can see the cookie ornaments, one the way it is supposed to look, and the others overfired. This kiln must have gotten to over 2200 F, I would guess.

The porcelain beads are vitrified and while they didn't stick together like the terra cotta did, I don't think I can really use them for anything. I should really find something to do with them, they are very sturdy actually, just all white and matte. It is too hard to try to glaze them, as the glaze doesn't like to stick to vitrified clay...I have tried in the past. Any suggestions? Paint? sigh

Now I have to buckle down to catch up and redo everything that was lost. So that is my tale of weekend woe and burnt cookies. One of the sad days in the life of a ceramic artist...


  1. Waaahhh! The cookies actually look like a nice chocolate from my view. What about tea staining the white ones? I have no idea about clay so I don't know if that even works. I'm sending you 'catch up' vibes.

  2. The burnt ones are actually a really nice color...they look like the actual clay when it is wet. very chocolatey. Unfortunately the iron in the clay starts to fuse, so most of them are stuck to each other and chip when taken apart :(

    OH! Tea staining might work! Or coffee. The porcelain is pretty non-porous but there may be enough for it to soak up some stain. It feels a bit like ivory or bone. I am going to try that!

  3. Wow, I can't believe the bowl! I would never have thought that could happen! I did the same thing a couple of weeks ago, but with glass. I moved the temp probe out a bit while I situated my shelf, then forgot to put it all the way back in. So you see, it can still happen with a controller! If it makes you feel better, I think you've posted a really important lesson here... thanks!

  4. I'd suggest trying a stain wash, maybe with some corn syrup mixed in to ensure that it sticks to the vitreous porcelain. (Make sure that there's some low-fire frit in the wash) and then fire them again to bisque temp to mature the stain. Then tumble them. Don't worry if a few of them stick a little to each other, the frit bond will be much weaker than the individual beads so they should separate easily and the sharp bits from the chipping will be polished off in the tumbler.

  5. Yeah, the bowl is really funny. Well not ha-ha funny to me. It looks like someone poured brownie mix on my shelf!

    Andi, great suggestions! I really need to play around with that. I should be able to do somehting with these...

  6. Bummer! I fire mine and go to bed, too. So far I'v been very lucky. One time I got up and the big kiln was still on but one of the elements had gone out so it was still trying to reach cone 6. The batch was easily refired after the element was replaced.

    You can reglaze the ones that vitrified. They take a long time to dry, about 3 times as long as a bisqued piece. And they have to be handled gently so the layer of glaze doesn't come off, but it is do-able.

    Oh .. here's a thought ... what about covering them with Art Clay Silver?

    Anyway, thanks for sharing.


  7. Natalie,
    Yeah Metal Clay is the only thing I have used that really works. I have done some glazes that work ok. Maybe I can find a couple that work and just glaze all of these in those colors for stock...you are right though, it does take a long time for it to dry...

  8. Perhaps they will end up being some of your favorite "mistakes" and you won't bear to part with them. :)

  9. I wonder if leaving them in a bowl of crushed blueberries would make them blue? People were always complaining about blueberry pie staining their fake teeth on tv when I was a kid.

    ps: I am so sorry!

  10. Geeez Melanie,
    I'm sorry this happened, but I am wondering can you use Mayco Metallics to salvage them?

  11. Can you do an acid wash to the vitrified ones, to rough up the surface and get them to a point where they'd accept glaze again? I'm thinking the acid paste that glass bead artists use for the frosted effect...

    Sorry about the meltdown... :(