[Clayart] Redart vs Kaolin

Tue Jun 13 13:39:01 UTC 2023

I would love a copy as well. (I do have the Mastering Cone 6 Glazes book
and find it's my most referenced resource.)

Best,
LJ Cohen

On Tue, Jun 13, 2023 at 8:13 AM Mary Winter <mary8252 at gmail.com> wrote:

> Ron, I would be very grateful for a pdf of your glaze course, is there a
> charge for it, please let me know if there is.
>
> Cheers
>
> Mary
>
> On Tue 13. Jun 2023 at 02:51, <ronroy at ca.inter.net> wrote:
>
> > When I am working on glazes and clays I focus on alumina content.
> > Alumina is the hardest oxide to melt so increasing it will make a
> > glaze of clay body fire higher. If a glaze is melting too much adding
> > alumina fixes the problem.
> >
> > In glaze calculation lowering fluxes is the same as increasing alumina
> > and silica so it can be done either way or some of each.
> >
> > The percent of alumina in red art is 17.35, in kaolin it's usually
> > over 40% and in EPK it's 43.89 using the analysis in my materials table.
> >
> > Subbing red art into a glaze for kaolin is going to lower the melting
> > point of a glaze.
> >
> > On top of that one of the things alumina does is hold a glaze on a pot
> > and keeps it from running off.
> >
> > The iron in red art is 7.44% - in EPK it's less than 1% so there will
> > be a colour change unless the colour is already saturated.
> >
> > If anyone wants a copy of my glazes course book I can send a PDF - 32
> > pages with analysis of common materials, function of oxides in glazes
> > and much more.
> >
> >
> >
> > RR
> >
> >
> > Quoting ran mcc <ranmcc at msn.com>:
> >
> > > I was trying to find out the difference between redart and kaolin to
> > > use in glazes.  I have subbed redart for kaolin in changing one
> > > glaze and really did not see much difference in outward appearance
> > > of glaze or melting.
> > >
> > > Get Outlook for Android<https://aka.ms/ghei36>
> > > ________________________________
> > > From: Clayart <clayart-bounces at lists.clayartworld.com> on behalf of
> > > Terry Lazaroff <terrylazaroff at gmail.com>
> > > Sent: Sunday, June 11, 2023 11:14:56 PM
> > > To: Clayart international pottery discussion forum
> > > <clayart at lists.clayartworld.com>
> > > Subject: Re: [Clayart] Redart vs Kaolin
> > >
> > > Yes;  I was asking what are people doing to find a replacement to
> > > Gertsley Borate.  You are probably aware it is now around $500.00
> > > for a bag.
> > >
> > > Terry
> > >
> > > Sent from my iPad
> > >
> > >> On Jun 11, 2023, at 9:52 PM, ronroy at ca.inter.net wrote:
> > >>
> > >> ?Hi Terry,
> > >>
> > >> Was there a question - if so it did not come through. Perhaps send
> > >> it to me directly and I will repost.
> > >>
> > >> RR
> > >>
> > >> Quoting Terry Lazaroff <terrylazaroff at gmail.com>:
> > >>
> > >>>
> > >>>
> > >>> Sent from my iPhone
> > >>>
> > >>>>> On Jun 10, 2023, at 4:46 PM, ronroy at ca.inter.net wrote:
> > >>>>
> > >>>> ?It will lower the melting point of any glaze dramatically and
> > >>>> lower the maturing temperature of any clay body dramatically.
> > >>>>
> > >>>> Colour will also be affected.
> > >>>>
> > >>>> All that said - it depends on how much kaolin there is to start
> > >>>> with. If only 1% of kaolin then not much will happen but if we
> > >>>> are talking 20% then start looking for new kiln shelves and maybe
> > >>>> a new kiln.
> > >>>>
> > >>>> RR
> > >>>>
> > >>>>
> > >>>> Quoting ran mcc <RANMCC at msn.com>:
> > >>>>
> > >>>>> Other than more iron is there any positives or negatives or
> > >>>>> affects by subbing redart for kaolin?
> > >>>>>
> > >>>>> Get Outlook for Android<https://aka.ms/ghei36>
> > >>>>> -------------- next part --------------
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> > >>>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>> Ron Roy
> > >>>> ronroy at ca.inter.net
> > >>>> Web page ronroy.net
> > >>>>
> > >>>>
> > >>>
> > >>
> > >>
> > >>
> > >> Ron Roy
> > >> ronroy at ca.inter.net
> > >> Web page ronroy.net
> > >>
> > >>
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> >
> >
> >
> > Ron Roy
> > ronroy at ca.inter.net
> > Web page ronroy.net
> >
> >
> >
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