gina mars on thu 25 mar 10
Hi All, the purple glaze recipe was cone 6ox
soda spar 45.7
flint 15.2
talc 12.7
gerstley 12.9
dolomite 9.0
epk 4.5
bentonite 1
cobalt carb 2.0
manganese carb 5.0
I will fire it without the manganese and then make a batch with both
to see what happens.
I have to wait for the manganese to come in the mail.
The magnesium is just as LIght as the manganese in
the bag which makes it confusing also. Does anyone have any idea what
to do with all the magnesium carb? I feel like it is never going to get
used in my glaze studio.
Gina Mars
www.marspottery.net
John Britt on thu 25 mar 10
Gina,
Now I am really confused. Did you substitute Magnesium Carbonate for
Manganese Carbonate? (From Lili, it seemed that was not the case, rather=
=3D
that you substituted Manganese Oxide for Manganese Carbonate.)
If you did, substitute Magnesium Carbonate for Manganese Carbonate? yes i=
=3D
t
will make a difference.
5% Manganese Carbonate is a lot!
You will probably still get a lavender as you have so much magnesium oxid=
=3D
e
in the recipe from dolomite and talc, and cobalt will give lavender/purpl=
=3D
es
with magnesium oxide. But it will be much lighter than with the manganese=
=3D
carbonate.
Let me know if that helps,
John Britt
www.johnbrittpottery.com
Steve Slatin on thu 25 mar 10
Gina -- I understand your frustration, and
know that the last thing you want to hear is
that you've gotta test it ... but in this case,
you'll have to.
Manganese is a colorant -- it darkens things,
leaves specks, etc. Magnesium is a flux, and
you can have quite a nice clear-ish glaze
with substantial amounts of magnesium in it.
Your glaze is rich in melters already, (especially
given that cobalt is such a powerful melter) and
you may well get odd results just because your
melters are such a large proportion of the glaze.
Then again, Magnesium is a more powerful melter
at ^10 than at ^6, and it tends to increase
viscosity (this is why it's a large ingredient
in some bead glazes). It also tends to thicken
the glaze in the bucket, but you've also got
bentonite in there ...
It also tends to turn cobalt glazes purple, though,
so there's some good news there. When you test,
do it on a 'waster' so you don't risk damaging a
shelf.
Personally, I'd be very interested in your results --
good or bad.
Steve Slatin --
--- On Thu, 3/25/10, gina mars wrote:
> Date: Thursday, March 25, 2010, 5:37 AM
> Hi All, the purple glaze recipe was
> cone 6ox
> soda spar 45.7
> flint 15.2
> talc 12.7
> gerstley 12.9
> dolomite 9.0
> epk 4.5
> bentonite 1
> cobalt carb 2.0
> manganese carb 5.0
> I will fire it without the manganese and then make a batch
> with both
> to see what happens.
> I have to wait for the manganese to come in the mail.
> The magnesium is just as LIght as the manganese in
> the bag which makes it confusing also. Does anyone have any
> idea what
> to do with all the magnesium carb? I feel like it is never
> going to get
> used in my glaze studio.
> Gina Mars
> www.marspottery.net
>
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