Maid O'Mud on sat 31 aug 02
Hi all gurus:
I was reading the ^5/6 recipe for Burke's celadon, and realized that =
this is a ^6 recipe with no frit :-)
My biggest concern, though, is durability. Can anyone give me their =
educated best guess if this looks to be a stable glaze base? I could =
sure use the cost savings right about now (miserable summer sales....)
I greatly appreciate the time anyone is willing to give to analyze this =
for me. Thank you.
Burke's Celadon-a faux celadon is oxidation-cone 5-6
feldspar-potash-any kind seems ok 58
whiting 17
flint-I use 305 mesh silica 14
ball clay 6
Zinc oxide 5
Sam - Maid O'Mud Pottery
Melbourne, Ontario CANADA
"First, the clay told me what to do.
Then, I told the clay what to do.
Now, we co-operate."
sam 1994
http://www.ody.ca/~scuttell/
Ron Roy on mon 2 sep 02
Hi Sam,
This glaze has enough silica and alumina to start with for a durable glaze
- but it has to be properly melted as well and I can't tell that from the
recipe. It also depends on how much colouring oxide is added.
Zinc oxide often is responsible for pin holing problems in amounts over 2%
- make sure the bisque firing is "clean" and proper ventilation during both
bisque and glaze firing - zinc oxide is very easily reduced above 950C to
zinc metal which boils and not only produces bubbling of the glaze but also
is lost as a flux during that process.
And who says zinc oxide is cheap - I just looked at the one of the US
catalogues I have and a 50 lb bag of Zinc oxide is listed at $90 and a 50
lb bag of F3134 was only $44 - so - while it depends what frit you buy -
frits are not as expensive as they appear to be - and they don't have the
disadvantages that zinc and Neph Sy have.
As a few people have pointed out - making your glazes reliable - even if it
costs a few dollars extra per bucket is smarter than saving a few bucks -
think about it - losing even one pot per firing is not cost effective.
RR
>I was reading the ^5/6 recipe for Burke's celadon, and realized that this
>is a ^6 recipe with no frit :-)
>
>My biggest concern, though, is durability. Can anyone give me their
>educated best guess if this looks to be a stable glaze base? I could sure
>use the cost savings right about now (miserable summer sales....)
>
>I greatly appreciate the time anyone is willing to give to analyze this
>for me. Thank you.
>
>Burke's Celadon-a faux celadon is oxidation-cone 5-6
>
>feldspar-potash-any kind seems ok 58
>whiting 17
>flint-I use 305 mesh silica 14
>ball clay 6
>Zinc oxide 5
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Maid O'Mud on mon 2 sep 02
Hi Ron:
Of course, you are right. I really hadn't noted the zinc (as I cut and
pasted the recipe rather than typing it out). Zinc is a pain, and not
cheap. Thanks for the "reality cheque". Your receipt is in the mail
Sam - Maid O'Mud Pottery
Melbourne, Ontario CANADA
"First, the clay told me what to do.
Then, I told the clay what to do.
Now, we co-operate."
sam 1994
http://www.ody.ca/~scuttell/
----- Original Message -----
From: "Ron Roy"
To:
Sent: Monday, September 02, 2002 2:10 PM
Subject: Re: Burke's celadon - RR
>snip>
> As a few people have pointed out - making your glazes reliable - even if
it
> costs a few dollars extra per bucket is smarter than saving a few bucks -
> think about it - losing even one pot per firing is not cost effective.
>
> RR
>
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