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cobalt won't fade like blue jeans

updated tue 14 jun 05

 

bill edwards on sun 12 jun 05


Cobalt is stable. If there is fading where cobalt is
used it would be from another compound within the
glaze if the light change is reasonably rapid when
exposed to UV light. If it fades in weatherd
conditions, there's issues within that glaze.
Cobalt on it's own accord is one of our higher
ligh-fast colorants used extensively for that reason
and of course the color blue.

Bill Edwards
Edmar Studio and Gallery

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marianne kuiper milks on mon 13 jun 05


hi Bill,
Thank yuou for taking the time to look at this.
The recipe I used is as follows:
flint 150
kaolin epk 25
f4 100
talc 90
gerstley borate 160
cobalt carb. 5
red iron oxide 5 (I used "special red" from Cer.
Supply)
rutile 25 (light rutile)

I fired this at ^6 electric.
I like the glaze, it was very interesting with neat
little lines (hare fur or something like that?)
The cup which I dipped and which stayed inside still
has those little lines running down (prob. from
rutile)
the ones(4) and bowl I put outside are distinctly
lighter and do not have the little lines any more.
They did.
I'm just curious if you can figure this out.
Thanks! Marianne Kuiper Milks

--- bill edwards wrote:

> Cobalt is stable. If there is fading where cobalt is
> used it would be from another compound within the
> glaze if the light change is reasonably rapid when
> exposed to UV light. If it fades in weatherd
> conditions, there's issues within that glaze.
> Cobalt on it's own accord is one of our higher
> ligh-fast colorants used extensively for that reason
> and of course the color blue.
>
> Bill Edwards
> Edmar Studio and Gallery
>
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> Tired of spam? Yahoo! Mail has the best spam
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