Sunday morning electric kiln conundrum

Yeah, I know many of the fuelled kiln afficianados think us electric kiln firers have it easy ... just push a button and wait for the same ol' results. Well, in my experience, limited as it is, I find I am constantly having to monitor and tweak my firings (and btw, I love, love, love my Cone-art kiln and it's Bartlett controller, which allow me the flexibility to make those tweaks). Thank goodness, for this round of glazing, I had the common sense to say "hmm, haven't glaze fired red clay for awhile, maybe I should run some tests first" (see .... old dogs can learn from their past mistakes;)). Last night, after unloading a small load of pots done with no fuss glazes, plus tests for the glazes for the remainder of the pots, I found my normally satin semi mattes were a tad on the glossy side. And one of them, for which I had to make a new batch this go round, isn't even in the same ballpark as far as colour goes. Cones are over as should be. Program ran as usual, minus the now frequent cool down hiccup, for which I have a programmed work around (note to self ... gotta talk to the Bartlett guys). So this morning is going to be spent scratching my head ... was it the load size?, the red clay?, was it the texture accents I added?, should I try an older version of my cool down ramp? .... finally, does it really matter? .. can I work with these results? (there isn't really anything wrong with them, it's just they didn't produce the expected results). The good news ... testing for texture accents were bang on! as were some of the tests for new glazes, an older glaze using an alternative firing schedule, and a new clay trial with all of the above. All yielded some possibilities for the future. I pinch myself sometimes, that I can go to work every day and have this much fun!
... PS ... I'll update this post with pics when I'm done pondering ;)
... PPS .... see Glaze Pics post below ....

Glaze Pics

So here's what I've been up to in the world of glaze testing this past week or so .....

Some background ... I make all my own glazes, save one commercial glaze (Spectrum's Textured Autumn), which I use because I love the way it breaks over texture on my white clay. When I set up my studio in 2008 and had to figure out what glazes I wanted to use, I turned to the book, Mastering Cone 6 Glazes. Given that my goal was to make functional pots to be used in the home, this seemed like a good starting point as I needed to be sure I was using safe glazes. As I've moved forward in my studio practice, I've continued to use the base recipes from this book for many of my current glazes and in new tests. The captions in the pics labelled HCSM and GB are references to the High Calcium Semi Mattes and Glossy Bases in the book. In addition, I use some older well known glazes such as Opal, Barry White, Nutmeg and Cream Rust. I also have buckets of Randy's Red and my 'effin' nemesis, Freakin' Floating Blue, with which I have had not much success with but continue (for reasons unknown to me, other than I am stubborn), to revisit periodically, like again this past week. And just to add another element of complication to my usual practice of doing a round of glaze tests each production cycle, I am on the hunt for a rustic looking clay. Meet Laguna's Speckled Buff (WC403).

Round one of tests .... going old school and eliminating the programmed cool down cycle in hopes of getting some remembered results from some old glaze recipes ... Barry White over Randy's Red, Opal and Floating Blue (not shown as it was a no show AGAIN!).

Ahhh, there is some red in Randy (a controlled cooling makes it muddy brown) .... not too bad. Even better on the new clay

Might be a keeper ... I like it better than it's brother shown on the bowl below

I have customers who love the light version of Opal obtained by using my cool down cycle

Me ... I prefer the darker blue

Nutmeg and Cream Rust. Not bad on the trial clay

Round Two of tests ... back to the regular practice of using a programmed cool down cycle ...

These are 3 of the semi mattes (HCSM I base) I use on a regular basis. The purpose of the tests was to try Mason Stain 6600, Tenmoku Brown (GB2 base) and Licorice Black (GB2 base) as accents on the texture.

Not a great pic nor a great outcome ... tile on the left is a variegated grey semi matte I call Aspen. The new batch of same glaze on the left turned out much darker and glossier. The Mason Stain on the accent was ok but not great

A good result with the Tenmoku Brown accent under the semi matte glaze. I think it's the accent that has upped the glossy quotient on the left

A good result with the Licorice Black accent under the semi matte glaze but it too is glossier than usual

Years ago I bought my first kiln from a elderly woman who was retiring from pottery. She threw in everything, including the kitchen sink, and all her glaze materials. I still have much of the older stuff I got from her including gems such as Albany Slip. I've been doing some research and here are some results .....

I also added some new glazes to the testing cycle. Most of the results were disappointing (I will try them again when I fire with my white clay). This Oilspot was the best of the bunch ....

Not the best pic and it doesn't accent texture as much as I'd like but it turned out to be a nice variegated blue/green

Finally .... just so you know I actually do make some pots .... here's a couple of mugs from the few pots I fired with the test tiles ....