[Clayart] fast firing

ronroy at ca.inter.net ronroy at ca.inter.net
Thu Feb 25 22:13:11 UTC 2021

Hi Paul,

First - I think glazes have a range of maturity. What I consider  
mature would depend on my sensibility.

I think what you are asking is unanswerable and to a large extent  
dependent on the criteria applied.

What would be your definition?

I have the feeling that whatever you say a mature glaze is - somebody  
will come up with an exception.


Quoting paul gerhold <gerholdclay at gmail.com>:

> Hank,
> I don?t think I ever suggested that that downfiring and rate of  
> downfiring will not affect results on crystal glazes. My question is  
> about how rate of firing to a given cone affects the final result.  
> As Carol so nicely showed difference does occur in saturated metal  
> glazes.
> Still looking for a definition of what constitutes a ? matured  
> glaze? other than it achieves the objective the potters set for a  
> glaze.
> Paul
> Sent from my iPad
>> On Feb 25, 2021, at 7:14 AM, Hank Murrow <hmurrow at efn.org> wrote:
>> ?
>>> On Feb 24, 2021, at 3:01 PM, paul gerhold <gerholdclay at gmail.com> wrote:
>>> I have a degree in Chemical Engineering which is irrelevant to my  
>>> question on defining glaze maturation which so far nobody has  
>>> given a science type answer. And of course every glaze performs  
>>> differently at a specific cone. The question asked is there a  
>>> significant difference in a glaze if it reached the same at  
>>> different rates of firing?
>> Dear Paul;
>> Based upon my experiments with down-firing in oxidation, I see  
>> large differences in appearance with as little as 2 to as much as 8  
>> hours of this régime around 1850F. Most of my glazes are flux matts  
>> or flux semi-matts, and they respond wondrously to this treatment,  
>> which I discovered while trying to get increasingly red Shinos.  
>> Holding glass brought to maturation under mostly reduction  
>> conditions, seems optimum for fully melting them, but holding at a  
>> moment of crystallization during the cooling seems to deepen the  
>> color response. I find that bigger changes in color and surface  
>> result from this regime than from holding at higher temps, and  
>> eliminates the chance of overfiring at the same time.
>> Cheers, Hank Murrow

Ron Roy
ronroy at ca.inter.net
Web page ronroy.net

More information about the Clayart mailing list