I used to fire in an old ceramic kiln with a manual controller. (A knob that went from 1 thru 10) I had a hard time annealing with that kiln and figured that's where my breaking was coming from. One day I made an especially beautiful piece, the next morning I came into my shop to find it broken in half and full of small cracks.
![Shocked :shock:](./images/smilies/icon_eek.gif)
![d'oh! #-o](./images/smilies/eusa_doh.gif)
http://f1.pg.photos.yahoo.com/ph/74dodg ... kenPotMelt
The ones that crack in half I figure is an annealing problem, the ones
that get all those little cracks, well, I have no idea what's causing them. And why didn't they develop until after I sandblasted?
I'm using all Spectrum compatible glass. Here is my firing schedule for the pot melt.
AFAP to 1675°
Hold for two hours.
600° per hour to 1050°
Hold for 1HR 30 Minutes.
100° per hour from 1050° to 700°
Let the kiln cool on it's own, no venting.
For some reason this peticular color combination is giving me the most trouble. White, two shades of amber, clear and a little black. The cracking quite often is where there is white and clear together but not always.
Does anyone have any suggestions why this is happening?
Could it be the high temps, maybe Spectrum glass doesn't like to be that hot ?
Is it eh clear?
The sandblasting?
Annealing?
Naturally I have a gallery that's interested in them and wants a dozen pieces by the first of the year.
I'm at my wits end !
![Brick wall ](*,)](./images/smilies/eusa_wall.gif)
![Brick wall ](*,)](./images/smilies/eusa_wall.gif)
![Brick wall ](*,)](./images/smilies/eusa_wall.gif)
![Brick wall ](*,)](./images/smilies/eusa_wall.gif)
Thanks for the help,
Randy