Friday, December 26, 2014

Stilts

I've fired several kiln loads of work over the past few weeks. These loads have consisted mostly of small pieces with no base and therefore no logical ending place for the glaze. When I apply glaze on all sides, I need to stilt each piece so that the glaze won't melt and stick the piece to the shelf. 

stilted pieces in the kiln after firing

Most of my shelves have kiln wash on them, meaning they've been coated with a layer of material that keeps glaze from sticking to the shelf. If I were to get glaze on the bottom of a piece, the glaze would melt, stick to the kiln wash and later lift off the shelf easily with a bit of kiln wash on the bottom.
checking the fit of the stilt before loading into the kiln

If I put glaze on the bottom of a piece that is loaded on an un "washed" shelf, the glaze will melt, sticking the piece to the shelf. Removing the will take a bit more effort, and may result in part of the piece sticking to the shelf and breaking away from the piece, or vise versa. Glaze on an unwashed shelf usually results in damage to the piece or the shelf.

four point metal "jacks" stilts and a variety of ceramic stilts with metal points

To prevent damage to the piece from kiln wash and to prevent damage to my unwashed shelf, I load these small, bottomless pieces on stilts. I have a wide array of stilts, including metal pointed stilts with three or four prongs and some four-pointed metal stilts that look a bit like jacks. I can arrange pieces so that they each have a stilt or two or three. More points of contact between the stilt points and the piece makes the piece more stable and less likely to tip off the stilt during loading or firing.

the white spot is where the glaze melted to the shelf after this piece rolled of its stilt during firing or loading

After firing, the glaze has melted, but, assuming the glaze hasn't run down past the point of the stilt, the metal leaves a tiny hole in the glaze that is more or less invisible. If you look carefully at "China" dishes that have a shiny surface inside and on the foot, you can see three or four tiny holes in the glaze on the bottom. These holes are the marks of the stilts used to hold up the pot in the kiln. If your dishes have a matte surface on the bottom, but are shiny on top, they were "dry footed" during the firing and never had glaze applied to the bottom so that it wouldn't melt during firing. These pieces didn't require stilts to keep them from melting during firing.

3 comments:

  1. great information I am thinking of investing in some stilts to fire some forks and spoons and may just do so after the new year. thanks,

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  2. I always wondered about that! Thanks for the great info and something new to try.

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  3. I always wondered about that! Thanks for the great info and something new to try.

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