Jan Wallace Cone 6 Test Results

[Jan Wallace]

Below are the results from my first batch of Cone 6 tests. I collected a number of glaze recipes, alot from this site and from other sources. The 17 glazes I picked were used mostly in combinations of two, one base glaze and another over the top.

The 17 glazes used; Chris Harris Tenmoku, Licorice, Nutmeg (revised version), Waxy White, Floating Blue, Floating Red, Variegated Blue, Water Blue, Water Green, E C Wide Base Blue Matt, Speckled, Chrome Tin Red, Jen's Juicy Fruit (no colourant), Zinc Semi Matt Light Blue, Green Matt, Val Cushing Green Ash, Hannah's Fake Ash. I purposely chose a selection of matt, gloss and semi gloss glazes. The clay i used is a white earthenware that matures at 1180 deg c. My supplier who also processes the clay, assured me it would be fine for Cone 6.

As this my first time to really test a variety of glazes, I will tell you how I went about it, so that you can see how I achieved my results AND so that those who have more experience can comment / advise on what I can change in the future order to get better results.

Firing Info - I have a small, manual electric kiln, approx 40 x 40 cm. I used three kiln shelves, two large cones (6) one on the top and one on middle shelf. Cone on top shelf was touching toes nicely and middle cone malfunctioned as it lent on a test tilie when falling (silly me). I set my temp controller to 1220 deg c to allow for a soak at Cone 6.  I peeked in the kiln at the cone when pyro read 1200 dec c and cone had just started to bend. Fell within in the next 20 mins and kiln automatically shut off at 1220 deg c. Also, at approx 1020 deg c, I turned the kiln down in order to slow down the end of the firing to try to achieve about 65 deg c per/hr. Total firing time was 9 hours, which perhaps is a little slow? Pls let me know. I did not do a controlled cool as I had intended to do. My daughter was not feeling well that night so going out to the kiln to do this was not an option later in the evening. But at least I have tests now with a natural cool and next time I can do a controlled cool and will have a comparison. I don't know if it counts for anything but I read the temp inside the kiln the next morning and worked out that from the time the kiln shut off to the time I read the temp in the morning, the temp would have dropped at approx 93 deg c per hour (naturally, with all bungs in).

Observations - I feel that perhaps my bottom shelf may have underfired a little. Some of my test tiles looked a little matt that should have been glossier. I had a few blister/bubbles with a couple of glazes too. My nutmeg glaze turned out semi matt when i expected a gloss? Someone may like to enlighten me with respect to Nutmeg. Licorice seemed to give me overall dependable and nice results when used with other glazes. I had spread evenly the tiles so not to have all the same bases on the same shelf in case of a temp variation in the kiln. Perhaps some of my glazes where a little thin. I still have a list of other combinations I didn't get around to trying here.

Anyway, I will let you be the judge. Please let me know your thoughts as this is the best way for me/us to learn.

 

A - C H Tenmoku only

B - CHT then Waxy White

C - CHT then Zinc Semi Matt Blue

D - CHT then Zinc Semi Matt Blue then Hannah's Fake Ash

 E - CHT then Water Blue

F - CHT then Floating Red

G - CHT then V C Green Ash

H - CHT then Chrome Tin Red (has little flecks of red that are hard to see) 

 

I - CHT then Variegated Slate Blue

J - CHT then EC Wide Base Matt Blue then Hannah's Fake Ash

K - CHT then Juicy Fruit

L - CHT then Green Matt

 

 

A - Licorice only

B - Licorice then Chrome Tin Red

C - Licorice then Waxy White

D - Licorice then Nutmeg

 

 

E - Licorice then Green Matt

F - Lic then Water Green

G - Lic then Var Slate Blue

H - Lic then Floating Red

 

 

I - Lic then Floating Blue

J - Lic then C Harr Tenmoku

K - Lic then Zinc Semi Matt Blue

L - Lic then Speckled

 

 

A - Waxy White only (slightly green due to copper floating around in kiln)

B - WW then Water Green

C - WW then Green Matt

D - WW then Floating Blue

 

 

E - WW then C H Tenmoku

F - WW then Licorice

G - WW then Zinc Semi Matt Blue

H - WW then Water Blue

 

 

I - WW then Nutmeg

J - WW then V C Green Ash

K - WW then Hannahs Fake Ash

L - WW then Chrome Tin Red

 

 

A - Nutmeg only

B - Nutmeg then Speckled

C - Nutmeg then Floating Blue

D - Nutmeg then Var Slate Blue then Hannah's Fake Ash

 

 

E - Nutmeg then Licorice

F - Nutmeg then Chrome Tin Red

G - Nutmeg then Var Slate Blue

H - Nutmeg then Floating Red

 

 

I - Nutmeg then Waxy White

J - Nutmeg then Jens Juicy Fruit

K - Nutmeg then Green Matt

L - Nutmeg then C H Tenmoku

 

 

A - Water Blue

B - Water Green (crawling?)

C - E C Wide Firing Base Matt (Blue) Sure its not supposed to do this.

D - Floating Blue

E - Jen's Juicy Fruit (no colourant)

 

 

A - Variegated Slate Blue

B - Same as above

C - Floating Red

D - Floating Red then Licorice

E - Floating Red then C H Tenmoku

 

 

A - Green Matt

B - Green Matt then Waxy White

C - Green Matt then Licorice

D - Green Matt then V C Green Ash

 

 

A - Chrome Tin Red

B - Chrome Tin Red then Hannah's Fake Ash

C - Zinc Semi Matt Blue

D - Zinc semi Matt Blue then Licorice

E - Speckled (nice Matt)

F - Speckled then Licorice (very nice, almost like a woodfired look i think. Close up next)

 

F - Two examples of 'Speckled' with 'Licorice' over top

A - Speckled over a Copper & Iron Engobe/Slip

B - Jen's Juicy Fruit over a Copper & Iron Engobe

C - Tenmoku over a Chrome Engobe

D - Floating Red over a Chrome Engobe

E - Nutmeg over a Iron Engobe

F - Variegated Slate Blue over Iron Engobe

 

Thanks... if you have any questions, please let me know. Jan

 

 

 

 

[George Lewter]

Jan, Great job of doing all those tests, and then getting quality photos, and organizing the results for us to see. I think you got some very intriguing results, and some combinations that I would like to try out myself.

You mentioned "Water Green & Blue". Are those "Water Color Green" (& Blue) listed in the companion glazes discussion in the Steven Hill Oxidation Project Group or different glazes completely?

Thank you so much for sharing the results of your hard work.

[Jan Wallace]

Hi George, thanks for your comments. I have learnt alot from reading things from this site, so went without saying that i share my results too. I got alot from doing the tests and recording the results, but  really just touched the surface. It's the only way to learn isn't it. I have been making more test rings today. I have always liked the look of woodfired ceramics, so that is something I want to try to achieve if its possible. There we are a few glazes above that I am happy with that have some potential here.  

The 'Water Blue' and 'Water Green' I got from Alisa Clausen's flickr page which has a load of Cone 6 recipes and photos.

The recipe is;

77      Frit Ferro 3110 (I used Ferro 4110)

10      Silica (I used Eckalite 2)

7       Kaolin - EPK

6       Gerstley Borate - 1999

100

Add -

3       Bentonite

5       Cobalt Carbonate for BLUE   or 

2.5 Copper Carbonate for GREEN

I personally think that the amount of Cobalt Carb could be reduced a little as it is a very strong blue.

 

 

[June Perry]

Jan, I scrolled down but no pictures are showing up. Are the photo of the tests in another location?

 

June

http://www.shambhalapottery.com

http://www.shambhalaptotery.blogspot.com

[Jan Wallace]

Hi June, that is weird. I don't know why you would not be seeing them above? I will post the results this morning on my blog page, so have a look there too, but perhaps it has to do with your computer not having a certain installation/program to view in this way???

www.janwallacepottery.blogspot.com

 

[George Lewter]

I see a huge scrolling page with 19 photos

[June Perry]

It is weird. I can get them on my HP laptop, but not on my Dell Xps, even though both are using Windows 7, and I'm using the same browser. In any case, I was finally able to see them!Thanks for sharing your results. It looks like you got some very promising results!

I've got somewhere around 45-50 tiles (all I could fit in my tiny test kiln), loaded and will be firing them in my tiny test kiln tomorrow, hopefully approximately the Steven Hills soaking and firing down schedule. Each glaze is on three to four different claybodies, so they aren't a lot of glaze formulas; but I need to see what they do on the various claybodies that I might be considering using at cone 6 electric and cone 6 soda in the future.

 

June

http://www.shambhalapottery.com

http://www.shambhalapottery.blogspot.com

[Jan Wallace]

Very good. Looking forward to seeing your results too June. June and George, in your opinion, do you think that my results were typical of a 'non controlled cool' for the glazes I used here and is nine hours too long for a cone 6 glaze firing?  I value an opinion you and anyone else might have with respect to my results please. Thanks.

[June Perry]

I don't think you can look at someone's tests, especially when they're layered, to know if they are typical of a non controlled firing. Claybody, firing ramp, holds, etc. plus the glazes themselves will create the final result; and unless you're doing side by side tests using all the same glazes, same raw materials, same, claybodies, etc. - all things being the same except the firing schedule, you can't really get an accurate picture of how the firing schedule is impacting the finished product.

 

June

http://www.shambhalapottery.com

http://www.shambhalapottery.blogspot.com

 

[Jan Wallace]

Yes, that makes sense June. Thats why i am keen to do the same tests but with a controlled cool to see the differance in the results. Will be interesting.

[June Perry]

Jan, the schedule I used was to hold an hour at cone 6, drop down to 1700F, then fire down 50 degrees per hr rate to 1600, then hold 1 hour at 1600, then let the kiln cool naturally. This is a schedule that Steven Hill was using until recently. I think George said that now he doesn't fire down, just does the 1 hr hold between cone 5 and 6.

The early part of the firing went fast but slowed at critical points. I found that the thermocouple wasn't reading right then changed to one of the new ones around 1200F. It was as tiring firing that tiny test kiln manually as it is firing a larger, gas kiln, particularly at the end few hours when I was running back and forth every few minutes to check temperatures. The next Cone 6 glaze tests firing is going to be in my 9 cu ft Skutt, programmable kiln!

I should be emptying the kiln at some point this afternoon. If it's not too late I'll try to take some pictures. If not today, then tomorrow. I couldn't fit all the tests in the little kiln, so the rest will have to wait a few weeks till I get my cone 10 soda pots slipped, decorated and bisqued then mix up and dip another large batch of cone 6 glazes and make some cone 6 pots to help fill up the kiln.

 

June

http://www.shambhalapottery.com

http://www.shambhalapottery.blogspot.com

[Jan Wallace]

Hi June, I am very keen to see your results, especially your iron glazes with the controlled cool and one hour hold at Cone 6. I guess with Steven Hill's glazes, it is not as crucial for the fire down?

I can relate to the end of the firing being tiring. My manual kiln is out in the garage, so i had to go out of the house to check the kiln often. Think i will sleep out there next time ha ha. I have done that before (wood firing). The things we do....

[Benjamin Coffman]

Hi Jan,

I have a copy of the water color green by steven hill and it says to add 9% bentonite.....is that accurate? Thanks!

Ben