Steven's Glazes - Tested at Cone 6

[George Lewter]

Is anyone testing some or all of Steven's cone 10 glazes at Cone 6. If so, can you let us know about the results with close up pictures and firing details?

 

So, CM?!. Can you share any details with us?  Are the glazes all formulated the same as they were in his handouts, or has he made flux adjustments for the lower firing temperatures?  What kind of firing schedule are you using?  Are you also firing the gas kiln to cone 6?

 

I asked Steven a year ago if we could publish the Glaze recipes here, but never got an answer, so we've just referred our members to Lakeside Pottery where the recipes are online, but it would be nice to have them right here. 

[Mary Jane]

I am curious to know if anyone has taken this firing schedule and applied it to the MC6G recipes?  It sure would be nice if you could combine firings.  Seems like the philosophy is quite different regarding the drop after the hold at peak.  Cheers, MJ

 

[George Lewter]

Part 1 - Heat work is a function of both time and temperature.  The faster the temperature rise the higher the temperature must be to drop a cone.  The slower the rise the lower the temperature.  The object though, is not to simply do x amount of heat work, but to allow time at the most liquid stage of the glaze melt for some mixing and diffusing of compounds across the boundaries of glaze layers. The hazy yellow band near the rim of this  cup is an intermixing between the iron red of the interior and Hannah's fake ash blue that rings the top of the exterior.  I believe the yellow results from complex intermixing that must be given time to develop.   

Part 2 The question of glossy versus a matte surface has some different issues. Alumina mattes and, from what people are saying about Steven's rapid cooling cycle, strontium mattes can do their crystal building work at a sustained high temperature.  Calcium mattes on the other hand depend on slowly lowering temperatures from the peak to grow their crystals.  For all the mattes, it is the crystals that break up incident light so you don't get a hard reflection of a gloss glaze.  

[George Lewter]

The rough texture if the cooling is not rapid is an important detail to learn.  My biggest objection to Strontium Crystal Magic glaze has been the roughness of the surface, requiring extensive smoothing with silicon carbide sand paper after firing. It will beinteresting to see how much difference a fast cool makes.

[martha peddicord]

Thanks for that input.

Does this mean that we need to not combine the MC6 glazes and SH glazes either on a piece or on diff pieces in the same kiln?  That would be disappointing to me, I have so many MC^6 that I know and love, I was hoping to figure out a way to get happy with both.

Can you have a high temp soak and a slow drop in the same kiln and use both glazes?

 

Could we start a thread on that subject?  " The combination of SH and MC6 glazes."   I don't know how to open a new thread here. I open this kiln yesterday with some combo's that I really liked but I don't know how to submit pics yet.  I'm happy to tell about results and make suggestions to others.

[Teresa Wooden]

I use MC6 glazes and Steven's (SCM, SCMO, 2D Blue, Pier Black, Persimmon, Hannah's Fake Ash Blue, White Liner) with no problems except controlling the running, which is a matter of application, creating a foot on the form to catch the glaze, and practice, practice.  My favorite MC6 combos right now are Spearmint Green and Variegated Slate Blue with SCM and 2D Blue, and Pier Black.  I do fire these to cone 7.  Soak around 1600 degrees.  Slow cool.

 

All I can suggest is make some test cups and experiment with lots of note-taking.  The application is very critical, it seems...SCM only needs a very light coat, for instance.  Same for 2D Blue.  Caution to keep gloss glazes light on the bottom third of your pot or they'll "run like a mad cow" (heard that phrase from Fong Choo at a workshop...funny.)

 

In my experience, the way I pack the kiln makes a difference in the firing.  Packed really full, I'd expect to see some variation.  Also, if you have a digital control, check the segments of the firing to see if one or more of the elements is starting to burn out.  That plays havoc with a firing.

 

If anyone is interested, I'll post some pics of my green and blue glaze combos using Steven's and MC6...but they are fired to cone 7 (up to cone 9 with a soak) so I didn't know if it applied to this group.

[Mary Jane]

Teresa, just to verify, you are not doing a rapid temperature drop with SCM glazes?  George's comment yesterday indicated the lack of a rapid temperature drop would cause roughness on the SCM.  Sounds like you have not had that problem?  I am also seeing that you are taking the cone 6 glazes up to essentially cone 9.  I would love to see pics.  I take it you have not had any problems doing this.  Curious as to what clay you use.  My big issue with the firings on the prior SH firing schedule was clay selection.  I did not want to use porcelain and I had water tight issues when I used a cone 10 b-mix.  I hear that cone 5 b-mix bloats. 

 

Do you think that the SCM has the roughness problem with cone 6 firings but not cone 8/9? 

[Teresa Wooden]

I really haven't had problems with roughness from cone six through cone nine with SCM.  Maybe if it were applied thickly, but I spray a thin coating.

 

I have used my own stoneware mix to fire from six to nine.

I have used Laguna 550 porcelain for cone 7-9 and I love it.  Experimenting with some Tucker porcelain now.

 

My cone six firing schedule has a long cooling cycle, based on the MC6 schedule.

My cone 7-9 schedule is based on one Steven used a couple years ago and has a soak and then fast cool.  I'll try and list them here soon.

[Mary Jane]

I have done a few test tiles of the SCM at cone 6 but I have dipped them.  That likely means that the glaze is thicker than if i did a thin spray.  I have had roughness - so now I see that I will need to try spraying a test tile to see if the results are different.  The test tiles came out terrible - very rough.  I even tried remixing a sample batch to test a second time.  Don't know why it had never occurred to me to spray and just use a "real piece" for testing.  Cheers, MJ

[martha peddicord]

Concerning the application of SCM, SH said to use it as 80% of the over all thickness of glaze.  So,  yesterday I did just that and then use the R O as a modifier, hannah's ash gold at the top over bare clay, JJF/iron lightly misted over all.  Also Dusted JJF/iron over some MC6 glazes I use alot.  Opening kiln tomorrow AM.  We'll see.