Becky Kelsey on sat 21 oct 06
We have a cone 10 reduction glaze recipe called Larson's white, it is a
glossy glaze and for years we have had no problems with it. The last three
times that it has been mixed up, it settles into a nearly concrete hardpan
at the bottom of the bucket. We tried using distilled water instead of tap
water, and used CMC gum to try to suspend it better but to no avail. The
recipe is:
Soda Feldspar (Kona F-4) 2170
Whiting 620
Kaolin 200
Flint 790
Bentonite 155
Zircopax 310
This problem hasn't affected any other of our glazes (which are many)with
the exception of only one time on our Woo Woo Brown glaze, that recipe is:
Whiting 18
Feldspar (Custer) 42
Ball Clay 13
Flint 27
Iron Oxide 4
Rutile 4
Bentonite 1
We have only had the problem with the Woo Woo Brown once, now the glaze is
fine, but the problem persists with the Larson's White.
I hope someone can help us with this problem...Becky at Gavilan
linda rosen on sun 22 oct 06
My guess is that it has been mixed with too much water.=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Becky =
Kelsey
Sent: Saturday, October 21, 2006 6:48 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: larson's white glaze settles hard
We have a cone 10 reduction glaze recipe called Larson's white, it is a
glossy glaze and for years we have had no problems with it. The last =
three
times that it has been mixed up, it settles into a nearly concrete =
hardpan
at the bottom of the bucket. We tried using distilled water instead of =
tap
water, and used CMC gum to try to suspend it better but to no avail. The
recipe is:
Soda Feldspar (Kona F-4) 2170
Whiting 620
Kaolin 200
Flint 790
Bentonite 155
Zircopax 310
This problem hasn't affected any other of our glazes (which are =
many)with
the exception of only one time on our Woo Woo Brown glaze, that recipe =
is:
Whiting 18
Feldspar (Custer) 42
Ball Clay 13
Flint 27
Iron Oxide 4
Rutile 4
Bentonite 1
We have only had the problem with the Woo Woo Brown once, now the glaze =
is
fine, but the problem persists with the Larson's White.
I hope someone can help us with this problem...Becky at Gavilan
_________________________________________________________________________=
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Ron Roy on sun 22 oct 06
Hi Becky,
I'm surprised it's hard panning - must be the soda spar - try this - I've
increased the raw clay and taken out some of the soda spar - I used Custer
but I can do it with G200 if you like.
It should be the same glaze but don't mix up a big batch till you see if it
solves the problem and you have fired it - it still has all that bentonite
in it so be aware - that can lead to problems - maybe try a small batch
with only 2% bentonite.
I'm thinking it must be very thin in the bucket - have you tried adding a
solution of Epsom Salts? Let me know if you need instructions and give me
some idea about how much glaze you have on hand.
F4 spar - 22.0
Custer - 32.0
Whiting - 16.5
OM#4 - 10.0
Silica - 15.5
Bentonite 4.0
Zircopax - 8.0
Total 108.0
RR
>We have a cone 10 reduction glaze recipe called Larson's white, it is a
>glossy glaze and for years we have had no problems with it. The last three
>times that it has been mixed up, it settles into a nearly concrete hardpan
>at the bottom of the bucket. We tried using distilled water instead of tap
>water, and used CMC gum to try to suspend it better but to no avail. The
>recipe is:
>
>Soda Feldspar (Kona F-4) 2170
>Whiting 620
>Kaolin 200
>Flint 790
>Bentonite 155
>Zircopax 310
>
>This problem hasn't affected any other of our glazes (which are many)with
>the exception of only one time on our Woo Woo Brown glaze, that recipe is:
>
>Whiting 18
>Feldspar (Custer) 42
>Ball Clay 13
>Flint 27
>Iron Oxide 4
>Rutile 4
>Bentonite 1
>
>We have only had the problem with the Woo Woo Brown once, now the glaze is
>fine, but the problem persists with the Larson's White.
>
>I hope someone can help us with this problem...Becky at Gavilan
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Rebecca on thu 2 nov 06
Dear Ron,
Sorry for the delay in responding back after your great suggestion to our p=
roblem with the Larson's White glaze, I've been away for a bit. We have ope=
ned a new bag of F4 spar and mixed a small sample batch of the original rec=
ipe as well as a sample batch of your suggested revision recipe. We mixed t=
he revision sample suing your suggestion of 2% bentonite instead of 4%, and=
it seems that the dried glaze on ware seems a bit powdery, I suppose that'=
s because of the lessened bentonite. Our gas kiln is firing as we speak, bu=
t I'm not sure if any ware with your version of Larson's got into it. Both =
samples are small, so it is hard to tell if they would hardpan, but they bo=
th seem to settle, but not into "cement" as before. We're going to mix larg=
er batches to get a better idea about the settling issue. We're going to tr=
y Epsom Salts in the new batches to see if that will keep them more in susp=
ension. We had the assistants dispose of the original hardpanned glaze so t=
here's no need to try to resurrect it. We want to thank you so much for you=
r expertise as we were somewhat at a loss about what to do.
-----Original Message-----
>From: Ron Roy
>Sent: Oct 22, 2006 4:21 PM
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: larson's white glaze settles hard
>
>Hi Becky,
>
>I'm surprised it's hard panning - must be the soda spar - try this - I've
>increased the raw clay and taken out some of the soda spar - I used Custer
>but I can do it with G200 if you like.
>
>It should be the same glaze but don't mix up a big batch till you see if i=
t
>solves the problem and you have fired it - it still has all that bentonite
>in it so be aware - that can lead to problems - maybe try a small batch
>with only 2% bentonite.
>
>I'm thinking it must be very thin in the bucket - have you tried adding a
>solution of Epsom Salts? Let me know if you need instructions and give me
>some idea about how much glaze you have on hand.
>
>F4 spar - 22.0
>Custer - 32.0
>Whiting - 16.5
>OM#4 - 10.0
>Silica - 15.5
>Bentonite 4.0
>Zircopax - 8.0
>Total 108.0
>
>RR
>
>
>
>>We have a cone 10 reduction glaze recipe called Larson's white, it is a
>>glossy glaze and for years we have had no problems with it. The last thre=
e
>>times that it has been mixed up, it settles into a nearly concrete hardpa=
n
>>at the bottom of the bucket. We tried using distilled water instead of ta=
p
>>water, and used CMC gum to try to suspend it better but to no avail. The
>>recipe is:
>>
>>Soda Feldspar (Kona F-4) 2170
>>Whiting 620
>>Kaolin 200
>>Flint 790
>>Bentonite 155
>>Zircopax 310
>>
>>This problem hasn't affected any other of our glazes (which are many)with
>>the exception of only one time on our Woo Woo Brown glaze, that recipe is=
:
>>
>>Whiting 18
>>Feldspar (Custer) 42
>>Ball Clay 13
>>Flint 27
>>Iron Oxide 4
>>Rutile 4
>>Bentonite 1
>>
>>We have only had the problem with the Woo Woo Brown once, now the glaze i=
s
>>fine, but the problem persists with the Larson's White.
>>
>>I hope someone can help us with this problem...Becky at Gavilan
>
>Ron Roy
>RR#4
>15084 Little Lake Road
>Brighton, Ontario
>Canada
>K0K 1H0
>
>__________________________________________________________________________=
____
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink=
.com.
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