Alisa and Claus Clausen on mon 13 mar 00
------------------
Hi Ron,
Let me say that I apologize I read your message as personal, although
it was because it was under my header. I am miserable with this problem
right now, and I am getting touchy about it, because I am working
to resolve the shivering and crazing, and getting nowhere.
My supplier does not have the glaze or the engobe receipe.
I may have to surrender to the fact that they do not fit the white
body and not know why. Anyway, I will come back with more
info. when I get firing tests out. I reacted from a =22tired head=22
with no progress to show for myself. I know your intentions are
good and you are a major help and appreciated contributor.
I have another excuse....Denmarks sky sounds as low as
Janets, except I have yet to see the sun in many, many days.
I am all around grouchy. I have to snap out of it.
The fjord is warmer now than it was last month,
so time for another dip. That snaps anyone out or
anything..
Thanks a lot for your message below.
I have to get some inventory thrown for my
own purposes, and will soon get to the
community studio tomorrow to make some
more test. I will let you know if anything positive
happens.
All best regards,
Alisa in Denmark
-----Oprindelig meddelelse-----
Fra: Ron Roy =3Cronroy=40pop.total.net=3E
Til: CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
Dato: 13. marts 2000 03:00
Emne: Re: Sv: Re: Sv: Another shivering engobe problem
----------------------------Original message----------------------------
Dear Alisa,
First let me say I'm sorry to have been so abrupt in my post on this - I
was tired and should have waited longer and been more careful. My remarks
were not so much to you as they were an expression of my concern that we
all approach this subject with more care and understanding. I can see you
have been diligent and careful - more than most.
It is my opinion that it is either the slip or the glaze - as it always is
with fit problems - an incompatibility rather than blaming one or the
other.
It may also be the body underneath both - it would help if I knew what the
chips looked like. The bonding of all three layers - or rather the lack of
bonding can be part of this problem. A slip that does not have enough flux
will have a difficult time staying on the body - it just never gets melted
together properly. I would be interested to know what happens if you soak -
or if you do if you soak longer.
The other burning question is - can you trace this change to new body, slip
or glaze - sometimes manufactures put a batch number on their products -
this would be most helpful to both you and them when things go wrong. What
do they say about the shivering?
I suppose the question now is - when the glaze is on just the slip alone -
a sharp edge - does it shiver? Perhaps all three should be tested - glaze
on body and slip on body as well. Freezing the results would continue the
cooling more and would help aggravate the problem.
When you say the combination only crazed on the paper clay - and the others
were fine - the trouble with shivering problems is they are more difficult
to see. There are stresses set up when you have the opposite of crazing
that can be dormant for quite a while. What I am saying here is - in many
cases it is more difficult to spot the imbalances that can result in
shivering and dunting of ware.
This would all be so easy to deal with if I could see the recipe of the
glazes - it is usually quite evident when the expansion is calculated to
predict this kind of problem - especially when one glaze is crazing.
You are asking if it would be an advantage to simply mix up engobes and try
them - right? I think the answer is - maybe - you would have to test till
you found one that worked but at least you would know what you are working
with and could change it.
As I have said - I wish I had more experience in this - I have none - I can
change glazes to fit but slips are a much greater problem. I am working on
a few slips for others at the moment and I will get smarter at it as I get
some experience.
In the mean time - please keep me informed about your problem - I may be
able to help. I have found I do better at this kind of thing when I have
had time to think about them.
In the meantime - don't be mad at an old man who is ashamed of being unkind.
RR
=3E----------------------------Original message----------------------------
=3EDear Ron,
=3EMy original query was that I wanted to know in theory, if shivering can =
be
=3Ecaused by a bad fit between slips and bodies,
=3Eor only due to a bad fit between bodies and glazes. Peter was kind to
=3Egive me that information.
=3E
=3EThese particular slips and transparent glaze are all commercially made =
and have
=3Ebeen used over approx. 8 months the community studio. Of course I made =
test
=3Etiles, 2 for each color, one glazed with gloss transparent, one with mat.
=3EThey fired fine, no shivering. But the tiles were flat, no lips to get a
=3Ethicker
=3Eamount of glaze settling. At home I tried these commercial engobes on
=3Efour types of cone 6 stoneware. Only the paperclay crackled, the other 3=
fine.
=3EThe paperclay test was painted, as opposed to dipped, so I may have =
applied
=3Ethe glaze too thickly. As said, the glaze requires a low viscosity (40).
=3E
=3EAm I am reading your message to say I am lazy and expect this all these
=3Ematerials to work presto bingo?=21..well, that sure would be nice.
=3EI am not a lazy dum dum. However, when things do go wrong,
=3Esometimes it takes time to decide what the variables are and where
=3Eto begin a controlled leaping off point to make things correct.
=3EThus my queries to Clayart.
=3E
=3ERecently I have seen a fair amount of lips shivering. Therefore I am =
trying to
=3Ediagnose the problem by looking at the easiest problem to fix, and go on
=3Eprogressively to the more elaborate problems to fix.
=3E
=3EI have seen the engobes fit the white body with the transp. glaze.
=3ENow I have a problem.
=3EWhat has changed?
=3EThe batch of glaze.
=3EThat is why I am starting with the glaze.
=3E
=3EI do have a good idea of what fit is about. That is what lead me to my =
concern
=3Eabout
=3Eperhaps the engobe not fitting a particular body.
=3E
=3EIt is also my point that for my own work I make engobes made from the
=3Esame body
=3Eof the pots that I am going to paint the engobes on. Good fit.
=3EThe body that I use for brushing engobes is white, so no coverage =
problem.
=3E
=3EI was pondering if one is assured a fit with the same body engobe,
=3Ewhat would be the advantage of mixing up engobes from a different reciepe
=3Esuch a standard white, or Bringle, etc.
=3E
=3EBut that could be just as simple as what you said, to cover a darker
=3Ebody. But if one used a white body, are there any advantages to mixing
=3Eup a different receipe engobe?
=3E
=3EI would be interested to hear your opinion on that.
=3E
=3EBest regards,
=3EAlisa in Denmark
=3E
=3E
=3E
=3E-----Oprindelig meddelelse-----
=3EFra: Ron Roy =3Cronroy=40pop.total.net=3E
=3ETil: CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
=3EDato: 9. marts 2000 22:09
=3EEmne: Re: Sv: Another shivering engobe problem
=3E
=3E
=3E
=3E
=3E----------------------------Original message----------------------------
=3EWhy engobes are not tested for fit with both bodies and glazes is a =
mystery
=3Eto me.
=3E
=3EI recommend making test tiles out of it and trying your glazes on them. =
If
=3Ethey react the way your body does with your glazes then you are on the
=3Eright track.
=3E
=3EThe idea of inserting a layer of anything between clay and glaze and
=3Eexpecting it to be compatible without any experimentation is simply not
=3Eunderstanding what fit is about.
=3E
=3EI recommend making slips out of the same body you are throwing with - if
=3Epossible. If you are putting a light slip over a dark body then there is
=3Ework to be done and it is easier said than done.
=3E
=3ERR
=3E
=3ERon Roy
=3E93 Pegasus Trail
=3EScarborough
=3EOntario, Canada
=3EM1G 3N8
=3EEvenings 416-439-2621
=3EFax 416-438-7849
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
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