Friday, November 6, 2020

eyes glazed over

 The title is not a reference to anything political going on right now, rather it is the reaction I see when I try to explain the process/timing involved with the start to finish for these decal transfer mugs. I absorb new information better by reading than by listening, so here is a short rundown on the decal transfer mugs:

  1. The newly made mugs must dry before the bisque firing. I monitor the drying, making sure the handles do not dry before the rest of the mug by covering on and off with cloth and plastic sheets. The bisque firing is a partial firing used to make the clay strong but still porous so the mugs absorb glaze and also hold up to the glazing process. Bisque temperature reads as 1899 degrees F on my kiln, or approximately cone 05. 
  2. Once bisque fired, the mugs are glazed, loaded in the kiln with whatever other pottery is going in, and fired to a higher temperature.  In my case I glaze fire to cone 6 which reads as 2169 degrees F on my kiln.
  3.  Apply the decal images to the glaze fired mug.  The laser printer I print images with uses an ink which contains iron oxide which fuses with the glaze when fired.  
  4. Here's where a lot of the extra wait comes in: These decals fire to bisque temperature.  I find it works out best to just use the top shelf of the kiln for anything with the decal images.  That leaves two thirds of the kiln to fill.  Obviously I want to get the most out of a kiln firing so I am not wasting electricity by heating empty space, so I pause everything and go back to step 1, making more pots (greenware), and waiting for them to dry.

That's about it.  Below are some mugs from the last bisque firing.  The rest of the pots in that kiln load have been glazed and are now firing in the kiln behind the mugs.   

It is quite the hodge podge of images.  This firing happened just before going out of town last week and I decided to use whatever images I had left that were already printed instead of taking the time to make up new sheets.
In the picture below you can see the temperature readout on the kiln.  I still use Pyrometric cones, as the temperature in the top of the kiln is usually different from the bottom, and, especially with glaze, I want to know what I'm getting.
I will have these mugs at River City Farmer's Market, Marietta Ohio tomorrow morning, and hope your eyes are not glazed over.

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