Ron Roy on fri 24 dec 99
Hi again Ingaborg,
First of all I noticed I sent the wrong recipe for my next revision to
lower expansion more - I listed EPK as 9.5 when it should have been 13.5 -
notice the total on that one was only 96. It should have been:
G200 - 42.0
3134 - 18.0
whiting - 9.5
EPK - 13.5
Silica - 17.0
Total - 100.0 plus 0.35 copper carb and 3.0 tin.
I also noticed I did not include the other one with wolastonite and OM4
subbed in.
G200 - 40.0
3134 - 17.5
Wolas - 13.0
OM #4 - 20.5
Silica - 9.0
Total - 100.0 plus tin and copper carb.
Expansion is a bit lower than the above - I have kept the ratio
(alumina/silica) the same as 194.
Sorry for throwing that curve - to much overtime is my usual excuse - this
time I think it was sugar plums and fairies dancing in my head.
RR
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Ingeborg Foco on sat 25 dec 99
Hi Ron,
I was a little bit befuddled but with the revisions to the revisions things
are clear. I failed to mention in my report that I rubbed cobalt oxide on
the samples in hopes of seeing it drop into the cracks... negative. I seem
to have no ink on hand so used a magic marker and that was negative. Will
do the freeze/thaw test and see what happens. I don't mind doing the grunt
work since you're providing the brain power.
I have wanted to ask your opinion about one of your country men and his
methods of glaze formulation. In Robin Hopper's "Ceramic Spectrum" he
devises a numbering system for colorants 10% being the greatest amount ever
used down to 0.625% being the smallest amount. He drops all fractions in
the base glaze. Perhaps you are familiar with his methodology. At any
rate, I always alter my glazes in that manner and wonder how you feel this
affects the end product. I was hesitant to change your revisions as I
didn't want to add another variable into the equation.
Happy Holiday and I think it is time for me to get myself an
Egg Nog ---- without the Egg! Just a Nog.
Ingeborg
----- Original Message -----
From: Ron Roy
To:
Sent: Friday, December 24, 1999 9:37 AM
Subject: Re: RR's Revision to Pete's Red - hold everything
> ----------------------------Original message----------------------------
> Hi again Ingaborg,
>
> First of all I noticed I sent the wrong recipe for my next revision to
> lower expansion more - I listed EPK as 9.5 when it should have been 13.5 -
> notice the total on that one was only 96. It should have been:
>
> G200 - 42.0
> 3134 - 18.0
> whiting - 9.5
> EPK - 13.5
> Silica - 17.0
> Total - 100.0 plus 0.35 copper carb and 3.0 tin.
>
> I also noticed I did not include the other one with wolastonite and OM4
> subbed in.
>
> G200 - 40.0
> 3134 - 17.5
> Wolas - 13.0
> OM #4 - 20.5
> Silica - 9.0
> Total - 100.0 plus tin and copper carb.
>
> Expansion is a bit lower than the above - I have kept the ratio
> (alumina/silica) the same as 194.
>
> Sorry for throwing that curve - to much overtime is my usual excuse - this
> time I think it was sugar plums and fairies dancing in my head.
>
> RR
>
> Ron Roy
> 93 Pegasus Trail
> Scarborough
> Ontario, Canada
> M1G 3N8
> Evenings 416-439-2621
> Fax 416-438-7849
Ron Roy on sun 26 dec 99
Hi Ingeborg,
I don't think I understand your question - is it about colouring oxides?
There are general ranges for colouring oxides but very much depends on the
type of glaze - I say it is OK to use those general limits - but don't be
bound by them. Just remember - you want to use as little as possible
because of toxicity and cost. It is always better to alter the base glaze
to work well with the colours you want.
As for rounding decimals - it depends - some smaller amounts of strong
oxides can make a difference if you round off to a whole number - like
cobalt for instance - or in the main body a strong flux like lithium carb
could be crucial.
We have to understand about the empirical method - it's more about quantity
than accuracy. There is room for both systems of course and the best
results will be gotten using both.
I tend to get carried away when I am trying to duplicate a glaze with
different materials - I sometimes feel I need to use some decimals - it
becomes a target game - kinda silly I know but thats the kind guy I am!
I am quite sure you could round off most decimals and you would not be able
to see any difference in the great majority of glazes - but every once in a
while I would guess you could.
RR
>----------------------------Original message----------------------------
>I was a little bit befuddled but with the revisions to the revisions things
>are clear. I failed to mention in my report that I rubbed cobalt oxide on
>the samples in hopes of seeing it drop into the cracks... negative. I seem
>to have no ink on hand so used a magic marker and that was negative. Will
>do the freeze/thaw test and see what happens. I don't mind doing the grunt
>work since you're providing the brain power.
>
>I have wanted to ask your opinion about one of your country men and his
>methods of glaze formulation. In Robin Hopper's "Ceramic Spectrum" he
>devises a numbering system for colorants 10% being the greatest amount ever
>used down to 0.625% being the smallest amount. He drops all fractions in
>the base glaze. Perhaps you are familiar with his methodology. At any
>rate, I always alter my glazes in that manner and wonder how you feel this
>affects the end product. I was hesitant to change your revisions as I
>didn't want to add another variable into the equation.
>
>Happy Holiday and I think it is time for me to get myself an
>Egg Nog ---- without the Egg! Just a Nog.
>
>Ingeborg
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
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