The Companion Glazes - Modifiers and Complements to SCM

[George Lewter]

These are the glazes that Steven introduced us to for creating the layered effects for which he is renown. This is the place to post modifications for these glazes, and other glazes that you have found to work well with SCM and SCM for orange.

 

 

2-D blue sprayed very thinly over the other layered glazes can produce a "snowflake effect.

And following are companion glazes that Steven has used on his pots.

 

 

 

[Jan Wallace]

Thanks Sylvia. I think they look GREAT! Well done.

[June Perry]

Sylvia, that recipe, with the added silica is lovely, but it will never drip like a fake ash because of all that silica. All the fake ash glazes have a few things in common - high whiting which mimics ash, and low silica and lower alumina which allows the dripping. Fake ash glazes often work better by spraying than dipping.

Just a shot in the dark, but I think if you took the original Hannahs fake ash, and just added that bit of frit that he shows in the adjusted recipe, it may just give you what you want. Also, I don't have both recipes side by side. Do both the old and new have the same amount of clay? If they don't then you might use the lower amount of clay. I'd also try the new recipe without the silica and see what you get. The base recipe would add up to 100 without the silica.

June

[Jan Wallace]

Very interesting June. Thanks for helping us to understand how all this works. That makes sense.

[W. Kern Hendricks]

Very colorful!  I note lots of glossy highlights in the photo.  I've got a couple of SH's cups and they wouldn't reflect light at high noon on June 21 in the Mojave desert.  So, I wonder what else is going on with your cups.  Matte finishes in well melted glazes result from crystal formation upon cooling.  They may also depend upon the formation of tiny seed crystals upon rapid cooling from peak to about 1700F.  This suggests that you may not have cooled fast enough from peak to form the seed crystals and/or allowed for crystal growth between 1700-1500. 

Alternatively (or in addition to), the clay body may be contributing to this.  Somewhere in this long thread is information about the clay that SH uses.  Being scientifically educated, I think the place to start if you want to learn about what someone else has achieved is to use exactly the same materials and process that they used and then start modifying things from there.  Otherwise, you end up in the dark speculating upon what might have happened when things don't turn out as you hoped.

I lived in central Oregon for ten years.  This entire area is volcanic.  There is obsidian (shiny glass), basalt (flat black) and granite (large crystalline light gray).  All forms are very close chemically.  The real difference comes from the cooling rate - days in the case of obsidian to thousands of years in the case of granite.

[Sylvia Shirley]

You are right that mine are more glossy than Steven Hill's, but copying his look exactly is not terribly important to me.  I don't mind a little gloss.  Right now I'm working on learning the spraying techniques more than anything.  (I built a spray booth just so I could do this project.) This was my first attempt with using his method, and overall I am pretty happy with the results.  The glazes do seem to fit my clay body pretty well.  I use Flint Hills cone 6 porcelain, and love it, so I'm not interested in switching clays.  I also intend to try every glaze on my shelf (and I have MANY) as companion glazes with his Strontium Crystal Matte, hoping to find a really interesting combination that makes it more my own.  I have to say that I have been in a real slump, disappointed with my current work, frustrated with the limits of firing electric, and feeling like I was going nowhere, but now I am excited again. So that alone made it worth doing.  My second attempt goes in the kiln this afternoon.  I can't wait till tomorrow!

[Sylvia Shirley]

June,

I mixed the same version but left out the silica.  I figured that little bit of 3195 was added to help the melt at cone 6, and without the silica it adds up to 100.  I'll let you know if that works better.

Sylvia

[Sylvia Shirley]

I got a response from Steven Hill and he said yes, there were a couple of errors on the glaze formulas on the dvd.  He said that the silica was not supposed to be in the fake ash.  So, there it is.  Right from the horse's mouth.  He sent me a sheet with revised formulas.  Here are the three that are corrections from the glaze sheet that accompanied the dvd:

Hannah's Fake Ash

Strontium Carb  10.1

Whiting  29.0

Redart Clay  56.1

Frit 3195  4.8

Total 100

Add

Red Iron Oxide  3.3

Yellow Iron Oxide  2.8

Bentonite  1.0

SH Copper Ash

Dolomite  2.8

Whiting  32.5

EPK  24.7

Flint  6.0

Alberta Slip  19.1

Frit 3124  14.9

Total 100

Add:

Bentonite  2.0

Copper Carb  5.6

Watercolor Green

Custer Feldspar  45.5

Flint  16.1

Lithium Carb  3.8

Frit 3124  4.7

Whiting  15.2

Strontium Carb  7.1

Copper Carb  7.6

Total 100

Add:

Bentonite  2.8

[Don Olliff]

Sylvia,

The watercolor green recipe is a bit strange compared to the others. It include the copper carbonate in the total. The others don't include the oxides. Did you notice that? What would the percentages be to correct that?

Thanks,

Don

[Sylvia Shirley]

Don,
I noticed it, but don't have an easy way to recalculate it. That's the way he had it, so I don't see what real difference it makes. Anybody else know?

[Jan Wallace]

Sylvia and Don,

I found the 'Water Colour Green' and 'Water Colour Blue' recipe on the Lakeside pottery website some time ago. The batch amount was much greater (was actually added up incorrectly on their site) and actually equals 3255grms not 3225grms as they state. I simply divided the amounts by 30 to bring the batch amounts back to around 100 for mix up for tests.

The recipe I then used on tests was this -

Custer Feldspar         48

Flint                        17

Lithium Carb               4

Frit 3124                   5

Whiting                    16

Strontium Carb          7.5

Total                      100

Add:

Copper Carb             8.0

Bentonite                 3.0

FOR BLUE REDUCE THE COPPER TO 6% AND ADD 1% COBALT CARB

Here are the pics from my recent tests. They came out beautifully. I dipped them on the test rings.

I also tested them over SCM. The SCM were dipped and then dipped in water colour grn and blue. I know they are not recommended to be dipped but since I was doing other tests, I though why not give it a try. They turned out okay, but nothing exciting. I did however have a nice surprise with a couple of other glazes over SCM. A couple of photos below.

This is 'Emily's Purple' over SCM (cool on left and warm on right)

 

This is Variegated Slate Blue' over SCM (cool on left and warm on right)

[martha peddicord]

I tried dipping some test pieces last firing, have been spraying and doing OK, but wanted a quick test of some different combos.  The SCM dip dried quickly on the bisque. Then I dipped the 2nd layer, quick in and out. The 2nd glaze sort of slid down the piece, a little test vase, not covering the SCM in patches. The combo of the 2 glazes did not dry after several minutes, I had to take the heat gun to it to get it dry enough to load. I repeated this with other combos, and other clays, same results.  This is my first try at dipping.  The glazes were not thick and all well behaved untill put over the SCM, which dried quickly on it's own. Any idea what was going on?  The over glazes were ones I use regularly.  

The fired results had a super satiny feel, but not much color change from the use of the SCM under, except for Varigated Blue, which was similar to what we see above.

At the workshop I attended, SH said the SCM should be 60% of the total thickness of the layer of glaze on the piece.  I had less, if it had been that thick, I think it would have slid off into the 2nd glaze bucket when I did the 2nd dip.

Any thoughts?

[Lawrence Weathers]

several places in this discussion there are screenshots of glaze formulas that appear to be made with FileMaker. if this is in fact FileMaker, is a blank version of this template available anywhere?

Thanks

Larry