Craig Martell on fri 19 nov 99
>Ivor commented:
>Since a eutectic point is a precise temperature the quotation seems to be a
>nonsense statement. I do not have the mathematical ability to sort out the
>Algebra which would enable me to calculate the weights of Wollastonite,
Hello Ivor:
Since I am the one that is guilty of babbling the nonsense about eutectics
I should make some attempt to clarify my point.
I was speaking about observations regarding fusion line blends of feldspars
and calcium introduced with whiting and or wollastonite. There is a strong
"melt" that can be observed at about the 70/30 point with spar being 70 and
whiting being at 30. Whether or not this is a true eutectic is open to
endless debate. The term gets tossed around a lot even though the true
phenomena may only be a myth. It's a way of talking I guess. I will edit
my nonsensical statement to read "strong melt". Eutectics may or may not
be attainable and understood. My aim is to make glazes and understand how
they work and I can do this with or without eutectic precision.
regards, Craig Martell in Oregon
Earl Brunner on sat 20 nov 99
Yes, lets not split cones. I always (and this may be a bit symplistic)
considered the working definition of the phenomenon that we call a eutectic to
be : The point at which when two chemicals or combination of chemicals (glazes)
are combined they melt at a lower temperature than either one by itself. i.e.
they form a eutectic. Therefore I understand Craig to be saying here (and I
think correctly) that a *strong* eutectic is one where the resulting melt is
*significantly* lower than either of the other melting points. If I'm correct,
I vote with you on this one Craig.
Craig Martell wrote:
> ----------------------------Original message----------------------------
>
> >Ivor commented:
> >Since a eutectic point is a precise temperature the quotation seems to be a
> >nonsense statement. I do not have the mathematical ability to sort out the
> >Algebra which would enable me to calculate the weights of Wollastonite,
>
> Hello Ivor:
>
> Since I am the one that is guilty of babbling the nonsense about eutectics
> I should make some attempt to clarify my point.
>
> I was speaking about observations regarding fusion line blends of feldspars
> and calcium introduced with whiting and or wollastonite. There is a strong
> "melt" that can be observed at about the 70/30 point with spar being 70 and
> whiting being at 30. Whether or not this is a true eutectic is open to
> endless debate. The term gets tossed around a lot even though the true
> phenomena may only be a myth. It's a way of talking I guess. I will edit
> my nonsensical statement to read "strong melt". Eutectics may or may not
> be attainable and understood. My aim is to make glazes and understand how
> they work and I can do this with or without eutectic precision.
>
> regards, Craig Martell in Oregon
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
Stephen Grimmer on sun 21 nov 99
Making small cones from large here, but the eutectic point is the _lowest_
melting point of two or more oxides. (There may be more than one, which adds
to the complexity of this subject.) A "strong eutectic" would be one in
which the slope of the graph of melting temperature versus mixture is steep.
There is a very good discussion of all this in F&J Hamer's book. Fascinating
stuff, I have to read it over and over.
Steve Grimmer
Bowling Green State University
Bowling Green, OH
----------
>From: Earl Brunner
>To: CLAYART@LSV.UKY.EDU
>Subject: Re: eutectic nonsense for Ivor
>Date: Sat, Nov 20, 1999, 4:07 PM
>
>----------------------------Original message----------------------------
>Yes, lets not split cones. I always (and this may be a bit symplistic)
>considered the working definition of the phenomenon that we call a eutectic to
>be : The point at which when two chemicals or combination of chemicals (glazes
>are combined they melt at a lower temperature than either one by itself. i.e.
>they form a eutectic. Therefore I understand Craig to be saying here (and I
>think correctly) that a *strong* eutectic is one where the resulting melt is
>*significantly* lower than either of the other melting points. If I'm correct,
>I vote with you on this one Craig.
>
>Craig Martell wrote:
>
>> ----------------------------Original message----------------------------
>>
>> >Ivor commented:
>> >Since a eutectic point is a precise temperature the quotation seems to be a
>> >nonsense statement. I do not have the mathematical ability to sort out the
>> >Algebra which would enable me to calculate the weights of Wollastonite,
>>
>> Hello Ivor:
>>
>> Since I am the one that is guilty of babbling the nonsense about eutectics
>> I should make some attempt to clarify my point.
>>
>> I was speaking about observations regarding fusion line blends of feldspars
>> and calcium introduced with whiting and or wollastonite. There is a strong
>> "melt" that can be observed at about the 70/30 point with spar being 70 and
>> whiting being at 30. Whether or not this is a true eutectic is open to
>> endless debate. The term gets tossed around a lot even though the true
>> phenomena may only be a myth. It's a way of talking I guess. I will edit
>> my nonsensical statement to read "strong melt". Eutectics may or may not
>> be attainable and understood. My aim is to make glazes and understand how
>> they work and I can do this with or without eutectic precision.
>>
>> regards, Craig Martell in Oregon
>
>--
>Earl Brunner
>http://coyote.accessnv.com/bruec
>mailto:bruec@anv.net
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