Hal Giddens on mon 25 sep 06
Hello everyone.
I need some help with getting an cone ^6 Emerald Green glaze to work on a
dark clay body, in this case Lizella clay. The reason we are using Lizella
is that we wanted to use a local Georgia clay. Last year when I was
working on the St. Patricks project using this clay I was only able to
come up with a dark green since I had such a short time to work with. This
year I have more time to work on the project and would like to get a glaze
that is at least close to Emerald Green. I did a test last week using 3
different glazes and only one of the result shows real promise. If any of
you have the time you can go to the link
http://wwwstpatricksproject2007.blogspot.com to view the test results and
the receipes used. Any ideas would be much appreciated. I did see a
receipe in the latest issue of Clay Times and I will probably give it a
try also.
Hal Giddens
Home Grown Pottery
1578 Rockledge Road
Rockledge, GA 30454
kenhal@bellsouth.net
http://www.homegrownpottery.blogspot.com/
http://wwwstpatricksproject2007.blogspot.com
Daniel Semler on mon 25 sep 06
Hi Everyone,
The URL should be http://stpatricksproject2007.blogspot.com instead
of that originally sent.
Hal, I'll try to have another look in detail later and let you know
if I have any useful thoughts on it.
Thx
D
Daniel Semler on wed 27 sep 06
Hi Hal,
Been thinking and looking around on this one.
Turns out I have more green glazes than I thought. The best colours =20
for what I think you're after were with chrome oxide. I'm working at =20
cone 10. Have some very nice pale transparent copper greens at lower =20
concentrations but its not really emerald. BTW these are oxidation =20
colours. So the best match for what I think might work for you of the =20
ones I have is a transparent gloss base with 1.25% chrome oxide in it.
I notice that you're greenest looking glaze (Emerald Green with =20
Soda Ash) has a little more chrome but its battling cobalt. I had a =20
look at that glaze by the way. Its a rather odd one. Its basically at =20
the very high end of cone 6 with silica and alumina and then its =20
fluxed by a ton of boron. Are you having any fit problems ? Boron in =20
high concentrations will act to increase rather than reduce expansion =20
so if you're ok this may be why, but it certainly calculates a low =20
COE. I am guessing the glaze might be pretty soft though.
So my guess would be cut back the cobalt as a first shot. If =20
stability and durability is important - I don't know what the vases =20
are to be used for - a more balanced base may be a good idea.
If you want to try out taking a cone 10 glaze I have down to cone 6 =20
and giving that a shot let me know. Mind you I was testing on =20
porcelain so we might have to opacify it for your stoneware.
Thanx
D
Hal Giddens on thu 28 sep 06
Thanks for the information Daniel.
I should have went into a little more detail on what I was doing but I was
trying to keep the post short. Last year I did 100 small vases (3" x 2.5)
for the St. Patricks Festival Committee here in Dublin Georgia for them to
sell as collectables during the 2 week St. Patricks celebration. Last year
I was notified by them on Christmas Eve and wasn't able to get an idea of
what they wanted until around mid January and had to rush the project and
go with the best glaze I could find that covered the red Lizella clay.
This year they want 200 vases and I was wanting to get a green lighter
that what I used last year and closer to Emerald Green even though it
doesn't have to be exact. These vases are fired to cone 6 in a small Skutt
kiln. Again these are collectable items and they want to sell different
items each year and maybe increase the number. Some years we may go to a
mug, bowl or some other functional piece but they probably wouldn't be
used for their function but they could be. This year I'm not concerned
about functionality since they will be vases around 4" x 3". I've received
a receipe from Colleen in Canada that I'm going to test this weekend and I
will also tweak the Emerald Green Glaze with Soda Ash per your information
and give it another test. I found the Soda Ash receipe in a list of glazes
I found on the web a few years ago and decided to give it a shot since I
was getting desperate.
Hal Giddens
Home Grown Pottery
1578 Rockledge Road
Rockledge, GA 30454
kenhal@bellsouth.net
http://www.homegrownpottery.blogspot.com
http://www.stpatricksproject2007.blogspot.com
Hal Giddens on fri 6 oct 06
First I want to thank all those with suggestions for my glaze problem.
Last week I made two more test glazes for the St. Patrick's project I am
working on.
Per Daniel Semler's suggestion I made a test batch of the Emerald Green
with Soda Ash glaze and cut the amount of Cobalt Carbonate to 7.5%. Then I
made a test batch of Hunter Green glaze that was suggested by Colleen
Raner. I fired both test pots using the glaze batches on Saturday and due
to revival at our church was not able to take pictures and post them until
last night. The pictures can be seen at my St. Pat's blog
http://www.stpatricksproject2007.blogspot.com.
The Emerald Green is still a little too dark and the Hunter Green looks
like it holds some promise. I will continue to do more testing with both
glazes. Any suggestions will be appreciated.
I also did some more Horse Hair firing last Saturday as well and some
other pots along with the St. Pats pots. They can be seen at
http://www.homegrownpottery.blogspot.com for those that are interested.
Thanks
Hal Giddens
Home Grown Pottery
1578 Rockledge Road
Rockledge, GA 30454
kenhal@bellsouth.net
http://www.homegrownpottery.blogspot.com
http://www.stpatricksproject2007.blogspot.com
Hal Giddens on wed 8 nov 06
I did some more test firing a couple of weeks back and it looks like I
have finally found a glaze that will work for my St. Patrick's project. I
want to thank all those that offered suggestions because I couldn't have
done it without your help. I would have posted sooner but I've had some
problems with blogspot and didn't get them resolved until I upgraded to
their new beta version. I will do some more testing with the glaze to get
it where it works with one dip in the glaze. Then after getting through
planning and participating in an art show later this month here in Dublin
and participating at the Oconee Cultural Art Foundation's Holiday Sale in
Watkinsville the first weekend in December I will get to work on those 200
pots.
To view the test pots go to http://www.stpatricksproject2007.blogspot.com.
I also did some more horse hair firing this past weekend and some of those
pots can be seen at http://www.homegrownpottery.blogspot.com.
Hal Giddens
Home Grown Pottery
1578 Rockledge Road
Rockledge, GA 30454
kenhal@bellsouth.net
http://www.homegrownpottery.blogspot.com
http://www.stpatricksproject2007.blogspot.com
Hilltop Pottery on wed 8 nov 06
Hal
I am not the glaze guru of any sorts but I did find a recipe on
gartside's site for a medium shiny green. It looks amazing in the
photos and thought maybe it's something you could use.
*_Medium Shiny Green_**_
_*Calcium carbonate 9
Frit 3195 21
Soda spar 23.8
Bentonite 2.4
Silica 19.1
Nepheline syenite 15.2
EPK 9.5
*_Add to Base_**_
_*Black copper oxide 3.5
I haven't tried it yet and don't know what cone it fires too but I am
thinking cone 6 since the glazes on that site were all cone 6.
Nancy
Hal Giddens wrote:
> I did some more test firing a couple of weeks back and it looks like I
> have finally found a glaze that will work for my St. Patrick's project. I
> want to thank all those that offered suggestions because I couldn't have
> done it without your help. I would have posted sooner but I've had some
> problems with blogspot and didn't get them resolved until I upgraded to
> their new beta version. I will do some more testing with the glaze to get
> it where it works with one dip in the glaze. Then after getting through
> planning and participating in an art show later this month here in Dublin
> and participating at the Oconee Cultural Art Foundation's Holiday Sale in
> Watkinsville the first weekend in December I will get to work on those 200
> pots.
>
> To view the test pots go to http://www.stpatricksproject2007.blogspot.com.
>
> I also did some more horse hair firing this past weekend and some of those
> pots can be seen at http://www.homegrownpottery.blogspot.com.
>
> Hal Giddens
>
> Home Grown Pottery
> 1578 Rockledge Road
> Rockledge, GA 30454
> kenhal@bellsouth.net
> http://www.homegrownpottery.blogspot.com
> http://www.stpatricksproject2007.blogspot.com
>
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>
Hal Giddens on fri 10 nov 06
Thank you for your input Nancy. However I want to stay with recipe's that
use glaze ingredients that I already have and I currently don't have any a
couple of those listed here.
Hal Giddens
Home Grown Pottery
1578 Rockledge Road
Rockledge, GA 30454
kenhal@bellsouth.net
http://www.homegrownpottery.blogspot.com
http://www.stpatricksproject2007.blogspot.com
On Wed, 8 Nov 2006 15:32:53 -0500, Hilltop Pottery
wrote:
>Hal
>
>I am not the glaze guru of any sorts but I did find a recipe on
>gartside's site for a medium shiny green. It looks amazing in the
>photos and thought maybe it's something you could use.
>
>*_Medium Shiny Green_**_
>
>_*Calcium carbonate 9
>Frit 3195 21
>Soda spar 23.8
>Bentonite 2.4
>Silica 19.1
>Nepheline syenite 15.2
>EPK 9.5
>
>*_Add to Base_**_
>
>_*Black copper oxide 3.5
>
>I haven't tried it yet and don't know what cone it fires too but I am
>thinking cone 6 since the glazes on that site were all cone 6.
>
>Nancy
>
>
>
Ron Roy on sun 12 nov 06
There is a lot of alumina and silica in this glaze if it is a cone 6 glaze
- If it does melt well I assume it's because of the above average boron and
the high amount of copper acting as a flux.
I also assume this would leach copper into food if it's used as a liner
glaze - I'd like to know how much if anyone has it tested.
It is above the limits so it's hard to predict just how good or bad it is.
RR
>I am not the glaze guru of any sorts but I did find a recipe on
>gartside's site for a medium shiny green. It looks amazing in the
>photos and thought maybe it's something you could use.
>
>*_Medium Shiny Green_**_
>
>_*Calcium carbonate 9
>Frit 3195 21
>Soda spar 23.8
>Bentonite 2.4
>Silica 19.1
>Nepheline syenite 15.2
>EPK 9.5
>
>*_Add to Base_**_
>
>_*Black copper oxide 3.5
>
>I haven't tried it yet and don't know what cone it fires too but I am
>thinking cone 6 since the glazes on that site were all cone 6.
>
>Nancy
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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