Magruder Red cone 6

[Joan Scott]

Iron oxide glaze John Britt

http://ncclayclub.blogspot.com/    From John Britt  Magruder Red cone 6

Here is a really nice cone 6 Iron red. And John said,"Don't have an image but trust me- it is nice! If you get an image - send it to me and I will post it."

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114.3%	Magruder’s (Iron ) Red cone 6 oxidation
44.8%	Minspar (soda feldspar}
12.3%	Silica
18.2%	Talc
16.1%	Tri-Calcium Phosphate (45.76% P2O5 + 54.23% CaO) vs 42.39% / 55.82% for Bone Ash
4.3%	EPK
4.3%	Lithium Carbonate
2.0%	Bentonite
12.3%	Synthetic Iron Oxide

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NOTE: Replies are posted from oldest to newest, so the most recent posts will be at the bottom of the last page.

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Test tiles on Laguna Haggi Porcelain (Norm Stuart)

[Norm Stuart]

I appreciate you catching my calc error comparing talc with silica and magnesium carbonate. I mistakenly used the metal oxide ration from Manganese Dioxide rather than Magnesium Dioxide. I sometimes get bleary-eyed from glaze calculations.

Digitalfire doesn't seem to report the same levels of Tin (Sn) in these fluxes. If these items contain tin it's only in trace amounts.

http://digitalfire.com/4sight/material/nepheline_syenite_1069.html

http://digitalfire.com/4sight/material/minsilspar_1029.html

http://digitalfire.com/4sight/material/custer_feldspar_253.html

http://digitalfire.com/4sight/material/ferro_frit_3110_349.html

http://digitalfire.com/4sight/material/ferro_frit_3269_371.html

[Joan Scott]

Wonderful information. Thanks. I do use neph sy frequently instead of feldspars. Can you reveal which frit you have found with the highest tin content? I think in one of my text I have the breakdown of constituents of the various popularly used frits maybe in one of Robin Hopper's books. Where do you go for this information yourself?

[Joan Scott]

No problem, thanks. 

[Jeff Poulter]

So Norm,

     On this recipe where Joan still has listed Crocus Martis, I think I will make it with the Special RIO & use the Crocus Martis from from NMC & see how it comes out.  When I made the test before, I couldn't find my Crocus Martis & used some Purple Hematite pigment from Rublev that I got from Natural Pigments.  Some of their stories about where all their pigments come from are pretty interesting.  They are pretty pricey, too!  jhp

Joan Scott said:

Interesting information. I have this for

ORANGE STREET:
Silica 15.2%
Talc 13.8%
Dolomite 8.1%
EPK 4.5%
Gerstly Borate 17.9%
F-4 Feldspar 46.8%
Red Iron Oxide 12%
Bone Ash 12%
Crocus Martis 6.2%

Is this the same as the one you pictured? Does your firing have any soak period etc.?

[Norm Stuart]

I can't wait to see your results comparing the Bayferrox 140 to the 180.

The Natural Pigments site is interesting.

http://www.naturalpigments.com/vb/content.php?3-Pigments

[Patricia Bridges]

I use the Readers Digest REd on Clay body #112 from Standard and it's VERY nice. the inside of the bowl on my icon is that glaze.

[Norm Stuart]

Readers Digest Red came out less red for me.

It looks to be sensitive to thickness of application on my test tile.  Have you found this to be the case?

[Patricia Bridges]

Yes -inside bowls and thicker. This is true will all red/browns from my experience.

[Norm Stuart]

Yet another Magruder Red test tile, with synthetic red iron oxide, fired faster.

[Joan Scott]

Thanks for posting the tile. Is that on a stoneware tile?

Norm Stuart said:

Yet another Magruder Red test tile, with synthetic red iron oxide, fired faster.

[Norm Stuart]

People make test tiles out of their scraps at our studio.

Based on our inventory, and the grog I can feel in the tile, I suspect it's this cone 5 clay:

WC-436 B-Mix with Grog ^5   http://www.lagunaclay.com/clays/western/wc436.php

The person who made the test tile claims it is:

WC-412 Stony White ^10   http://www.lagunaclay.com/clays/western/wc412.php

But this is less likely as cone 10 clays like Stony White don't feel this densified after firing to cone 6. Using white cone 10 clays, like Stoney White, at cone 6 causes pin-holing problems with many glazes as the clay remains porous and undensified at cone 6. The liquid glaze soaks into the bisque, and reacts causing long lasting gas formation.

[Joan Scott]

Thanks Norm that is useful to know.