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.

 

 

 

[Jeff Poulter]

You definitely have to do the slow cool & holds in order for the iron crystals to form.  There have been several articles linked on this forum to discussions about getting the iron reds.  I likewise have gotten good results on a test tile that did not translate to a pot.  I have found that they are easier to get in my smaller Skutt than my larger L&L. Of course the smaller kiln was a little more packed that my bigger one, so I'm sure that also comes into play.  You just have to find the sweet spot.  Jeff

[Sylvia Shirley]

Thanks Jan.  It seems I can never find stuff on these sites.

Sylvia

[Sylvia Shirley]

I have a question regarding the Hanna's Fake Ash glaze recipe that is included with Steven Hill's video.  If this has been addressed already, I apologize.  I searched and could not find anything about it.  

The recipe on the video's glaze list is not the same as the one you have listed here.  It is:

Hannah's Fake Ash

Strontium Carb  10.1

Whiting  29.0

Silica  22.7

Redart Clay  56.1

Frit 3195  4.8

(it says this adds up to 100, but it doesn't.  It is 122.7)

Additions are 

Red Iron Oxide  3.3

Yellow Iron Oxide  2.8

Bentonite  10.0

My question is, is this a typo, or has this been altered from the original version by adding the silica and the 3195?

Thanks,

Sylvia

[George Lewter]

This was under another topic:

Reply by graham strong on March 23, 2012 at 8:42pmDelete

One interesting note about the Steven Hill glaze list that came with his DVD.  I was talking with a potter who had the good luck of taking Steven Hill's week long class at the John Campbell Folk school.  He told me that Steven mentioned to the class that there was a typo in one of the recipes.  In the "Hanna's Fake Ash" recipe, the percentage for the colorant Bentonite is suppose to be 1.1%  Not 10%.  Good luck. . . . . End quote

I suspect the Silica is wrong also. That much silica would change  the glaze to something unrecognizable. The changes Steven has been making were to lower the firing range to cone 6.  Adding silica, especially almost 25% would be a step in the wrong direction since its melting point is 2570 deg F. I doubt the silica is supposed to be in the recipe at all.

[June Perry]

Actually, the silica isn't too high for a cone 6 glaze. It's 2.4 and the minimum in my Insight for cone 6 (non copper bearing glazes) is 2.5. For a copper bearing glaze it would be even higher. The whiting is quite a bit higher than recommended for cone 6. Also, the silica alumina ratio on this is over 11 which would make it a gloss and the original Hannah's is a matte.

You might want to write Steve and get the correct recipe; and maybe you can post the correction here. It would be interesting to see where the error was.

June

[Sylvia Shirley]

Thanks June.  I have a question pending to Steven, but thought maybe it had already been discussed somewhere here.  I'll just wait patiently for him to answer.  I know he's busy.

Sylvia

[George Lewter]

Hm . . . You're right, June. The Hesselberth and Roy cone 6 limit formulas also set 2.5 as min. I had thought the silica might be out of whack to facilitate the formulation of the characteristic rivulets.  Here is a side-by-side comparison of the new cone 6 version with the older cone 9 version. Notice the SiO2 in the original is only 1.54, and that was for cone 9.

I've yet to try the new version, but with the base recipe now totaling 122.7, one wonders if the colorants which are normally percentages of total are to be percentages of 122.7 (needing to be recalculated) or absolute as-is values (as if the silica were also an additive, rather than part of the base glaze). I just looked at the PDF recipe document from SH's DVD and silica is listed as a base ingredient, but the total is wrong. 

 

[Arthur Petch]

I just came on board seeking an answer to this very question of 122.7%.  I have concluded that the addition of 22.7 parts silica is an error.   It doesn't make sense that Steven's refinement process noted above should suddenly see the addition of this amount of silica.

[June Perry]

Arthur, that amount of silica is actually 0.1 moles less than the minimum for a good, cone 6, non copper bearing glaze limit. Sometime people add things to a formula and don't bother to bring it up to 100%. Since that glaze has no spar, or wollastonite to contribute silica, most of the silica has to be added alone. And of course it could be an error; but in that case, it would not be a very stable, functional glaze.

June

[Sylvia Shirley]

I just got a load of cups out of the kiln.  These all have the Hannah's Fake Ash from the recipe on the dvd, along the top 1/4 of the pot, feathered down. Not a bit of dripping happened from the fake ash.  I am mixing the other recipe and will try again with more cups.

[George Lewter]

What I can see is:

1. A very nice looking set of cups.
2. The fake ash is fully melted, which is not at all what I was expecting. I was expecting an immature grainy mess. So June is right about the quantity of silica not being excessive. It appears you need a much heavier coating to get rivulets (or as wine aficionados call them, "legs") started, if they are going to happen at all.
3. This technique of collaborating and sharing information is "da bomb"

[Sylvia Shirley]

George,

That fake ash was actually very thick, and still did not run.  I was afraid I would be cleaning shelves, because it was so thick, but no.  I do like the golden color though.  I should mention that this batch was mixed without any colorant.  Perhaps adding the iron would encourage a little running, but I doubt it would be much.

Sylvia