Mastering the Perfect Glaze in an Unpredictable Kiln

Two Different Results (The one on the right is the desired outcome)

I thought I would share a little bit about my long, very long process of trying to achieve the best results in my older kiln with a manual temperature gauge.  Up until this year I have been firing my work at a Co-operative Potters Guild which happens to be 40 minutes away from where I live.  It is a great little studio full of amazing people that have helped me get started in this industry.  I am so very thankful to them and having access to this studio was essential for me to develop as a maker/potter/artist.

About a year ago my dad found a used kiln for me while out browsing car parts at a swap meet, he purchased it and brought it home for me (best dad ever!)  While telling me about his find, he informed me he had already tested it and figured out how it worked without any previous knowledge on the subject, typical mechanic.

My Kiln

Then began the long process of trying to figure out how to use it properly and testing it while trying not to screw up too many of my pieces in the process.  I was having trouble trying to achieve the same results with my glazes as I was getting at the Guild.  They have a digital control which means you can control the exact timing and temps you want and program a schedule to fit your needs.  Mine on the other hand is a manual dial system, with a 1-10 scale of low to high. I won't go into to much detail on how they work since it is actually very technical, but the short of it is I needed to do a lot of trial and error.  I got the schedule they were using and asked some of the other guild members for some advice and then set out to try and replicate the same results in my kiln.

For some reason, after every firing I tried, one of my glazes was coming out very shiny and a slightly different colour.  I may have a bit of an issue with perfection and was becoming very frustrated with my close but not close enough results.  

I was just about to change my whole line of functional porcelain pottery to something different so I could become more independent and work entirely from home when I finally figured it out!  I applied the glaze a little bit thinner, and matched the exact highest temp to what the guild was firing to (not letting the kiln sitter shut off automatically), and slow cooled the kiln, dropping the temp 125 degrees per hour.  It worked!!!!!  The colour is perfect and has a buttery matte appearance like it should.


I guess this current line of my functional wares will hang around a little longer, at least until I sell enough of it to purchase a new bigger kiln with a digital control.  In the meantime, my perfect little used kiln is my new old best friend.