Tracey Dobbins on fri 5 jun 98
------------------
To the glaze sages out there...
Am about to try substituting zircopax for tin oxide. I'm thinking I may =
need to
actually increase the amount of zircopax to become more =22equivalent.=22 =
Has
anyone does this and figured a set increase to factor in? I plan to try the
Seths Luster recently listed...anyone tried this recipe inparticular with =
this
substitute? Thanks for any helpful suggestions.
Tracey
tracey=5Fdobbins=40nols.edu
Lorca Beebe on sat 6 jun 98
Zircopax or Superpax is often used by the Dept as it is cheaper than tin oxide
and some say is less toxic. I usually double the amount...
Lorca
Paul Lewing on sat 6 jun 98
Tracey,
I don't think I can give you an exact substitution amount of zircopax
for tin. But I did want to point out that in many cases this is not
an acceptable substitute. If you're just opacifying a glaze, and
leaving it white, the zircopax will work just about as well as the
tin, and save you a lot of money. And to male pastel colors, zircopax
may accually work better. But many times, in colored glazes, the
resulting color is just not as rich. I use a glaze in oxidation at
cone 5 that with 5% zircopax and 1% iron will be a nondescript tan.
But with the same proportions with tin, it will be a zingy
orange-brown. Most copper red recipes call for a little tin, and
zircopax doesn't do it there.
Paul Lewing, Seattle
Edouard Bastarache on sat 6 jun 98
Hi
i learned many years ago that 1% Tin oxide can be sustituted for by 2%
Zircopax(Robbin Hopper).
Edouard Bastarache
Tracy
Quebec
Canada
----------
De : Tracey Dobbins
A : Multiple recipients of list CLAYART
Objet : tin oxide vs. zircopax
Date : 5 juin, 1998 10:42
----------------------------Original message----------------------------
------------------
To the glaze sages out there...
Am about to try substituting zircopax for tin oxide. I'm thinking I may
need to
actually increase the amount of zircopax to become more "equivalent." Has
anyone does this and figured a set increase to factor in? I plan to try the
Seths Luster recently listed...anyone tried this recipe inparticular with
this
substitute? Thanks for any helpful suggestions.
Tracey
tracey_dobbins@nols.edu----------
Laura Conley on sat 6 jun 98
James Chappell's book Clay and Glazes recommends adding 50% more zircopax than t
oxide for feldspathic glazes and 20% more for borosilicate and potash glazes..
The tables in the back of this book are GREAT!!!!
Laura Conley
Tracey Dobbins wrote:
> ----------------------------Original message----------------------------
> ------------------
> To the glaze sages out there...
>
> Am about to try substituting zircopax for tin oxide. I'm thinking I may need
> actually increase the amount of zircopax to become more "equivalent." Has
> anyone does this and figured a set increase to factor in? I plan to try the
> Seths Luster recently listed...anyone tried this recipe inparticular with this
> substitute? Thanks for any helpful suggestions.
>
> Tracey
> tracey_dobbins@nols.edu
name Cat Jarosz on sat 6 jun 98
Dear Tracey
I'm not an expert but I do substitute super pax (now that zirco pax is
hard to get) for the tin in a recipe I use and i basically doubled the
amt. the recipe calls for 600 grams of tin so I use 1200 grms of super
pax and or zirco pax... super pax is a bit more expensive so it may not need
as much but it still looks good ... ps I use this mix for the liner glaze...
hope that helps you ... Cat
Bill Palmer on sun 7 jun 98
There are a lot of grades of zirconium opacifiers out there. The most popular
are made by Tam. The particle size affects the potency and the price, and
therefore the relative opacifying ability compared to tin. Tin also comes in
different mesh sizes, and again the finer the grind, the higher the potency
and price.
In general, I think the 2 Zirc. = 1 Tin, mentioned by various people is a good
rule of thumb. However, if Iron is present in the glaze as a colorant, I have
found that tin will greatly enhance warm tones and zirconium will kill them.
Bill Palmer, Marin Ceramic Supply
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