Orange Red Iron Glaze

[GreyBird]

Hi,

A while ago I was looking through the book "Glazes cone 6" by Michael Bailey, and I saw a picture of a beautiful rust red platter and it's glaze recipe. So naturally I had to mix that glaze.... which turned an ugly brown for me, naturally.

On the next page is a suggested test method of starting with the base and adding 1% increments of red iron ox starting with 0% and ending with 23%. I was determined to get this color and texture so I did all of that work.... All brown. I was disgusted and gave up.

The other day I was speaking to someone about glaze chemistry and he mentioned that Iron reds always turn brown in Oxidation and I remembered this failed glazeI had mixed. I don't know why I thought the recipe was for Oxidation. I just went and looked it up again in the book and I can't find any reference to either Oxidation or reduction for the glaze. I am going to keep looking but just thought I'd throw that out there to anyone who might have encountered the same recipe issue.

Here is the recipe with an image of how it should look (Page 89):

Had to delete for copyright reasons

Is it safe to assume that this color was achieved through reduction, not Oxidation? I just have a bit of trepidation about mixing up a bucket and trying it again, since so much work went into it last time but if I'm fairly certain it should go in the gas reduction kiln to achieve this color then I would try again. The back of the book says that all the glazes and examples were fired in an electric kiln so there you have it... This should have worked. Could it be a mistake?

Also had to delete image for same reason... so it will be hard to discuss a target color that no one will see. Oh well.

[GreyBird]

Here is the next page which states: "If the glaze fires a rather plain, satin brown, or looks like an under fired oil-spot glaze, it need either a slightly hotter firing or the maturing temperature of the glaze can be lowered by cutting out the 4% china clay and increasing the talc to 20.9%. Or the Feldspar to 50.7%" I remember that had tried firing to cone 7 with the same results. So I began to not trust the book. Childish I know, but it's an electric kiln and I put so much work into it and always got the same mud brown color. I REALLY love the color and want to reproduce it. Any other ideas? The previous page even mentions that the strength of the Iron Oxide is another variable, so it seams they've got every reason under the sun why this recipe won't work for you if you try it but look at this beautiful image and have fun trying to get there! LOL.

Also had to delete image for same reason

 

[Min]

It's an oxidation glaze. I used to think you had to slow cool to get those lovely oranges and iron reds but there is a forum member who did some testing comparing slow and fast cools here and got lovely results with a fast cool. Re the colour you got, long thread here, this Bailey glaze is brought up starting on page 2 of the thread. (spoiler alert: it's probably your iron)

[dhPotter]

Look in my Evolution Gallery. There are several pics of Red Orange, from John Britt's ^6 glaze book. If the glaze is not over another glaze it will be a metallic copper. If another glaze is present under the Red Orange it will NOT be metallic looking. All pics in the Evolution gallery are ^6 oxidation in an electric kiln.

Also, if the Red Orange glaze is not applied thick enough it will be brown.

Another glaze you might be interested in from Britt's ^6 book is Bailey's Red 2. In my Evolution gallery, the red white and blue pitcher is BR2. The yellowish part is BR2 over SCM Iron. BR2 is more red than the Red Orange.

i have recently tested Van Gilder Red from Britt's ^6 book. It is a lot like Bailey's Red 2. Maybe even redder.

[GreyBird]

Thank You Min! My Iron IS Very old. I've had a bucket of it for years, so I had ordered a few lbs of fresh Spanish Iron Oxide to give this recipe another go, but there were just so many variables that they mentioned I wasn't sure. I will read through the threads and see if it doesn't give me the courage to try again

[GreyBird]

Thank You DHPotter, I will keep this in mind too and look through yourEvolution Gallery.

[GreyBird]

Min, I read through the thread and looked at the test tiles you posted using the good Iron Oxide, but honestly, they just look brown to me, not the beautiful rust red pictured above in the book. Do you disagree? Also there is a matter of the texture and the breaking to black in parts. I'm not sure you've "nailed it" with those tile examples.

[Denice]

I have mixed this glaze for years and have never had any problems with it turning brown.   It comes out like the tiles posted,  I can see the orange and red in it with a oil spot back ground.  I believe this is the way Orange Red Glaze is suppose to look.  The type of clay you are testing it can make a difference also.   When I am testing a glaze I try it on several different clay's,  I think porcelain was used in the samples in the book.   You also have to consider the factor of going from a photograph to print production can change a color slightly.      Denice

[Min]

Those tiles are a different glaze, not the Bailey one. Look at the reds in the fast or slow cool thread. 

edit: tiles started with the Bailey recipe but then I tinkered with it as in the thread linked above. Tiles are a lousy photo, in reality they are a bit redder than shown.

[GreyBird]

Thanks Denice, Yes, I tested on Porcelain and Hazelnut Stoneware. Both looked the same dull brown. There's enough images in the book where there is no ambiguity about the target color. Min, Looking at those other threads now.

[GreyBird]

Min, Yes, those are better. I like the fast cooled ones better also. I will try with my Spanish Red Iron Oxide. They do all look a bit glossy though where the pictured glaze looked more matte/Satin matte or it could just be the photography.

[GreyBird]

They must have had a really special Red Iron Oxide. That's all I can say. The color on the pictured platter is magnificent. Well, it was before I had to delete all the images! LOL.

[GreyBird]

Min, in the fast or slow cool thread there is a lot of talk about SCM. What does that stand for? What is that?

[GreyBird]

1 hour ago, dhPotter said:

The yellowish part is BR2 over SCM Iron.

DHPotter what is SCM?

[Min]

1 hour ago, GreyBird said:

Min, in the fast or slow cool thread there is a lot of talk about SCM. What does that stand for? What is that?

Strontium Crystal Magic = SCM  there is a warm and a cool version. Started out as a Tom Coleman yellow crystal matte glaze and is used extensively by Steven Hill and those wishing to emulate his style of glazes. SCM is applied (usually by spraying) under another glaze to create lovely glaze variegations. Originally it was a cone 10 glaze but it was found to work at cone 6 also. 

Recipes: SCM Warm and SCM Cool

[GreyBird]

Thank you.  

[neilestrick]

@GreyBird Iron reds can vary greatly in their color depending on the clay body on which they are fired. I've got a great one here in the studio (cone 6), and it's fabulous on brown stoneware, pretty bad on porcelain, okay but not awesome on white stoneware.

[GreyBird]

Neil, Do you mind sharing a photo and the recipe? I use Hazelnut Stoneware so it may be nice on that.

[Dick White]

Everybody who said iron reds are tricky - is right. Everybody who is having trouble with iron reds coming out brown - join the crowd. I don't fully understand the exact chemical problems at the ionic valence level, but from an empirical standpoint, the troubles  in the US pottery world seem to have started when NYTAL talc when out of business and talc moved to Texas, and about same time, Mad Cows started mooing and real bone ash became scarce and replaced by synthetic TCalP.  Two suggestions which I have found successful -

1) refire your muddy brown iron glaze in your next bisque firing (following the usual glaze loading protocols, i.e., no touching). Iron reds need an extremely slow downfiring, to about 1700F to turn red. A slow upfiring back to bisque temperature is functionally about the same.

or,

2) change your glaze recipe one called Orange Street. Sample picture below.

EPK - 3.6

Gerstley - 14.9

Minspar soda spar - 39.5

Silica - 12.3

Texas Talc - 12.4

Dolomite - 7.1

Synth. Bone Ash - 10.2

RIO - 10

Crocus Martis - 5

[Min]

12 hours ago, Dick White said:

Iron reds need an extremely slow downfiring, to about 1700F to turn red.

Hi Dick,

Have a look at the fast cooled iron red versus the slow cooled one in this thread (first post). More variegated visual texture in the fast cooled but I do see it as quite red. Re talc, do you think it was something in the old nytal talc that helped the development of the red colour or something that wasn't in it? Have you seen any trials with omitting the talc and suppling the magnesium with magnesium carb to see if might be the latter reason? (or adjusting the dolomite)

 

[neilestrick]

14 hours ago, GreyBird said:

Neil, Do you mind sharing a photo and the recipe? I use Hazelnut Stoneware so it may be nice on that.

We use Harris Red. Google it, it's everywhere.

[Denice]

I didn't even consider that the talc could be the problem.    I had a lot of talc that was probably 40 years old,   I sold most of it to Marc C.   The old talc had abestos in it and he couldn't make one of his standard glazes with out it.     Denice

[neilestrick]

I use Texas talc now, and haven't seen any differences in my glazes.

[Russ]

Here's a John britt tomato red^10 wood fired reduction. This I do know about this iron saturate glaze.... it must be fired to

the prescribed temp or above and cooled very slowly for the color to appear. When I say appear I mean that it doesn't develop

the color till somewhere around 500f.  Before that it's a muddy brown. Don't ask me why it's just my observations. It takes my kiln

4 days to cool so I mean slowly.

[GreyBird]

Thanks everyone! Dick White that bottle is wonderful. I am going to try your methods  What clay body is it on?