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Crocus Martis Yellow? Grog Brains.


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#1 Karen B

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Posted 15 August 2014 - 02:21 PM

I must have grog for brains. I was mixing up 5 large batches of glaze yesterday.

Despite careful planning, I miscalculated and was short the amount of Yellow Ocher I needed for one,

which is to be a translucent green glaze, which I discovered about 11pm.

I was despairing, because schedules, deadlines, you know. I came across a bag of Crocus Martis Yellow.

It looked exactly the same! Yes, I used it to finish the glaze.

Now, as I am sieving, I notice some redness in the strainer.

PLEASE TELL ME IT IS NOT LIKE RED IRON OXIDE! Please tell me it is yellow when fired.

Just tell me the truth. Am I screwed?

Thank you,

Karen

 



#2 bciskepottery

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Posted 15 August 2014 - 02:53 PM

Crocus Martis is a form of iron oxide. Not much on the internet when searched for crocus martis yellow.

#3 PeterH

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Posted 15 August 2014 - 03:02 PM

All may not be lost, see
http://www.glazemixe...ie Yellow Matte

#4 Karen B

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Posted 15 August 2014 - 03:10 PM

Crocus Martis is a form of iron oxide. Not much on the internet when searched for crocus martis yellow.

 

I couldn't find anything either. Thanks for looking.



#5 Karen B

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Posted 15 August 2014 - 03:11 PM

All may not be lost, see
http://www.glazemixe...ie Yellow Matte

 

Good find! Thanks Peter, I'm now hopeful.



#6 Mark C.

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Posted 15 August 2014 - 05:26 PM

You now will have a new glaze one that is most likely a bit different from what you expect.

Since you did nor mention how much you put in? I would treat this like a glaze test

and not glaze all you work but just a few things until you know what you have.

Mark


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#7 Karen B

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Posted 15 August 2014 - 06:35 PM

As tempting as it is, I will do just that Mark, thank you.



#8 Babs

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Posted 15 August 2014 - 07:46 PM

Hope the person who was not going to kiln wash her shelves is reading......

Good luck Karen.

Got the chem comp of Yellow ochre?? FeOH

Prob will be paler as from reading, crocus martis unless calcined will gas off a lot in firing. therefore weight for weight it will give less colouring effect.( I think) Croc  FeSO4



#9 Karen B

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Posted 18 August 2014 - 08:11 PM

Lucky me. The test on the left is the glaze from the test batch. The test on the right is the new batch with the crocus martis yellow.

 

Just a note that the other colorant is Copper Carb.

 

 

Attached File  yogreen.jpg   125.31KB   4 downloads



#10 Karen B

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Posted 18 August 2014 - 08:13 PM

Hope the person who was not going to kiln wash her shelves is reading......

Good luck Karen.

Got the chem comp of Yellow ochre?? FeOH

Prob will be paler as from reading, crocus martis unless calcined will gas off a lot in firing. therefore weight for weight it will give less colouring effect.( I think) Croc  FeSO4

Wanted to thank you for the chem comp Babs.



#11 Babs

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Posted 19 August 2014 - 12:01 AM

Ah intuition somewhere you knew it was ok!  Nice glaze Karen it really picks up the texture.  Now what is cheaper? Crocus or Ochre? 



#12 Marcia Selsor

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Posted 19 August 2014 - 09:33 PM

Yellow iron and yellow ochre can be used as the same in some instances. I never heard of yellow crocus martins but It may work out ok for you.
Marcia



#13 Babs

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Posted 19 August 2014 - 09:52 PM

Could this be crocus calcined? Haven't calcined crocus but poss colour change?



#14 oldlady

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Posted 20 August 2014 - 06:25 PM

karen, i have some yellow ocher if you would like it.  have had it since early 90s and never used it. it weighs about a pound on my 1950s baby scale.  it is yours for postage if you like.


"putting you down does not raise me up."

#15 Karen B

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Posted 20 August 2014 - 11:37 PM

Ah intuition somewhere you knew it was ok!  Nice glaze Karen it really picks up the texture.  Now what is cheaper? Crocus or Ochre? 

 

,Thanks Babs.   I'll have to remember to look at the catalog when I go into the studio to look it up.

 

I don't think it is calcined, doesn't say on the label.



#16 Karen B

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Posted 20 August 2014 - 11:41 PM

karen, i have some yellow ocher if you would like it.  have had it since early 90s and never used it. it weighs about a pound on my 1950s baby scale.  it is yours for postage if you like.

 

Yes, I would like it. That is generous of you.



#17 oldlady

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Posted 21 August 2014 - 10:44 AM

will take it to the post office.  it probably will fit in the aprox $5 box.  pm an address.


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