What firing schedules have you used with the SH glazes?

[martha peddicord]

I finally have the glazes mixed from the March workshop I took with SH.  I would like to fire SH glazes in the same kiln with MC6G that I have been using successfully.  The cooling rates are very different.  I used the scedule SH gave us and the MC^6 glazes came out glossy, where with Hessleberth's firing recommendations, they are nice matts and satins.  SH says if strontium glazes are cooled too slowly they are rough.

 

Anyone??

[John Lowes]

I feel your pain, as I have recently completed a workshop with Steven in Atlanta and fired my pots I glazed in the workshop in my own kiln sitter equipped kiln. For my firing I had four pots from the workshop and maybe double that in "other" glazed pots.  I decided that I didn't want to take a chance at messing up my SH glaze pots, so I approximated his recommended Cone 6 (bisqued pot) firing schedule as best I could.  The results are here:

http://wynhillpottery.weebly.com/steven-hill-workshop.html

 The rest went pretty shiny using my own glazes over Strontium Crystal Magic; those results are in the bottom four rows here:

http://wynhillpottery.weebly.com/2011-work.html

In future firings, I think I may fire SH glaze pots on his schedule and others on the schedule I found to work for them.  I may try a couple of small kiln loads with some SH glaze pots with "other" glaze pots on the schedule best for those, firing down from Cone 6 to 1600 F over a period of 2-4 hours to see how it comes out. I may like more crystal development, and maybe the crystal development won't happen as he described in my kiln.  After all, I am not Steven Hill and I have my own style to promote.

[eleanor akowitz]

i have not used all the info i got from the sh workshop. first i went away for two months and then it took over a month to get back to feeling like working again. and now to top things off i have orders that must be filled and no time to experiment.  sometimes i wish i could insert another month in my life........  but i love looking in to see how others are doing on this project

eleanor in nh where the days are finally warming

[CM Partin]

It not a have it all situation. It's either on set of glazes or the other per firing with their respective schedules, sorry.

[CM Partin]

It not a have it all situation. It's either one set of glazes or the other per firing with their respective schedules, sorry.

[CM Partin]

Sorry to sound so glum, but each set of chemical combinations has a set of conditions that they fire the optimally too. Steven's were developed to work together as were Hassleberth's. Just as their are reduction glazes that simple cannot be achieved in electric oxidation. If you have a second smaller kiln it really helps a lot.

[George Lewter]

If you simply must have a MC6G high calcium matte in combination with a SH strontium matte, you can fire the MC6G slow cool cycle, but be prepared to spend about 15-30 minutes per pot wet sanding with 200 to 400 grit wet/dry silicon carbide sandpaper, smoothing out the over-crystallized strontium glaze. It can be made to be very smooth and look quite good.  

I had a bowl with Jens Juicy Fruit that was dazzling to look at because of the way it sparkled in the sunlight, but it was horrible to touch because each of those sparkles was a crystal sticking up out of the glaze surface.  I sanded it down, it lost its sparkle, but remained a rich coppery brown.It was fired with a 1 hour hold at 1742 deg. F to develop iron reds on other pots. But that is likely what caused it to get so rough.

[martha peddicord]

Thanks for the replies.

 

CM, Steven talked a good bit about using as little electricity as needed.  I'm wondering if the cooling schedule can be slowed any at all or if the rapid cooling was also developed in part to be energy efficient?  He encouraged us to try the SCMW and cool under our own glazes to see what we get.  

[Anthony Andersen]

I've had good results with SCM and MC6G on porcelain firing to 2140 or 2160 (^6 or ^6 1/2) with an hour hold, a 500 degree per hour quick cool to 1900 followed by a 125 degree cool all the way down to 1400, which is the current MC6G cool-down. I get a little gloss where the MC6G glazes are thick with the higher peak temp, but just a little. For pics, see all but the first 6 (they're ^8) in my electric reduction album.
http://cone6pots.ning.com/photo/albums/electric-reduction

More info is on my blog:
http://anthonyandersen.blogspot.com

[martha peddicord]

Thank you, I enjoyed your pics.  Very nice results.

At the school I attend, several pots with SCM as a base have come through the regular firing this week, mixed in the kiln with MC6 glazes on other pots.  They have been fired and cooled with the same schedule  the MC6 book calls for and there is no roughness of the SCM as long as it has a decent overspray of some other glaze. 

So.... I am totally confused.

 

I am firing today and I will try that here at home with 4 pots using SCM warm as a base and orange red as a monifier, hannah's ash over and let you guys know what happens.  I do know that when I did the quick cool ,9999 to 1600 that SH asks for, the cone 6 didn't even bend, I did not do the 1 hour soak at peak, only 20 min.  I was afraid of overfiring with that long soak.  .  So....other adjustments called for.......

[martha peddicord]

OK!

The results, very nice surface, no roughness. 

I used SCM W with red orange over all, and hannah's ash gold on top 1/4 on bare clay.  Nice legs, warm color, but not as much red orange as I would have liked.   Minor blistering inside the lip of one where there was maybe more ash glaze, and not as much SCMw not wiped off as well. I used the MC6 schedule, fired to a solid ^6, a 25 min hold, 500* drop to 1900* a 30 min hold there and then 125*/hour down to 1700*, then off.

While I didn't get any roughness, I did not get much shiney crystals.  The cones were tip touching 6 all through the kiln. ^7 was only slightly bent.  Does the strontium need more heat?

 

The other pots in the firing with MC6 glazes were great.

[June Perry]

I don't know about the cone for that glaze; but if the rest of the glazes look fine at cone 6, you may want to use a finer grained silica in some of the glazes which seem a bit drier than you like - either 400 mesh, or amorphous silica.

 

June

[June Perry]

It may just need more soaking, perhaps at the top, to develop the glaze more, and give the crystals a chance to grow. The other way to approximate a long hold at top is to slow the firing down a lot, two to three cones prior to top temperature. This is also good for glazes which tend to pinholes and blister, since too fast a firing on some of those glazes causes a boiling action if firing is too fast at this stage, which can then may cause those unwanted pinholes.

 

You might try the 1 hr hold at cone 6 starting or cone 5 plus 20 degrees which is what someone mentioned Steven is now doing, then fast cool to 1700 and soak there for an hour, then fire down 50 degrees F to 1600 and shut off. That's the schedule I'll use for my test firings if I don't get any more updated information on Stevens schedule.

 

Martha what is SCM W? I have the recipe for Strontium Crystal magic, but what if any additions are for the SCM W? Thanks!

 

June

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