Kathy McDonald on sat 25 mar 06
First of all let me thank those who took the time to
reply,,,
I have always done the acid test with any glaze that is to
go on food bearing surfaces. I did not know that lemon
worked as well as vinegar
glad I asked. I learned something new.
I'm not quite ready to ditch my practice of a "shop" "scrap"
glaze
or perhaps I should clarify...mixing one glaze with another
to get
something different. Most of what goes in as I stated is a
cone 10
hi dolomite semi gloss glaze..the rest are usually
cobalt,rutile, or iron /oatmeal
glazes
I've had some spectacular glazes derive this way. In fact
last year's
best copper red was my old recipe for Jeff's Red and a 1/2
full bucket
of Pete's Cranberry. I can replicate this one and I sure
plan too.
Ron your advice about leaving out the cone 6 er's is
probably good..
I think they may be the real wild card as far as ingredients
go.
Can anyone tell me what the difference is between layering
or sponging
a whole bunch of those glazes one on top of the other is in
terms of
how the chemicals ultimately interact with one another. I
know potters
who layer as many as 4 or 5 glazes into food bearing
pots..is this any different
in terms of customer safety.
Kathy
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of
Ron Roy
Sent: Saturday, March 25, 2006 12:39 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Question for the glaze experts:shop glaze
Hi Kathy,
You can always do the lemon test to see if the glaze is
grossly unstable.
You should have such glazes lab tested for leaching if you
are going to use
them as liner glazes.
In this case you may find those comercial cone 6 glazes may
be the weak link.
A good test to see if glazes are durable in an alkaline bath
(dish washer)
is to make two test tiles with the glazes on each - leave
one in the dish
washer and keep the other out as a control - just compare
the two every
month to see if there is any change.
RR
>Well..finally spring on the prairies and this is
>the time that I go out to the garage/summer studio
>and start getting set up for summer production.
>Clean up time,,,in other words.
>
>In the past I have always taken small portions of
>glazes that are left over and/or dried out and
>glazes that I didn't really like that well, or have
>decided not to use again and dumped them all into
>one big bucket and added about 5 kg of my white glaze
>some copper and cobalt to the mix. (Kinda like I cook, not
>terribly scientific I admit.)
>I fire to cone 10 R.
>
>This results in what I call a "shop glaze" that I use
>mainly for the outsides of pieces and sometimes for
>whole pieces ......if..... it turns
>out good that year. The glaze is normally somewhere
>between what I would call a satin matte
>and a semi gloss opaque blue/green colored glaze.
> Each year it's different.
>Some year's it's been spectacular.
>
>Glazes that are thrown in usually consist of some copper
>reds
>that I mix but don't like, a few cone 6 "screw-ups" , some
>commercial
>cone 6 glazes that are left over after winter and of course
>my primary base glaze that comprises most of the shop
>glaze...
> which is a hi calcium white cone 10 glaze.
>
>I know it can't be replicated this way , nor do I care I
>like
>the element of surprize. I normally use a liner glaze on
>functional ware but am wondering what, if any, safety
issues
>exist to customers with this practice. I also know other
>potters and some large studios that use this practice ,
>however
>they also use these glazes on the insides of functional
cook
>and tableware.
>
>I would not do that.
>
>Just looking for feedback from others and their thoughts on
>the practice.
>
>Kathy
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
____________________________________________________________
__________________
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your
subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.385 / Virus Database: 268.3.1/292 - Release
Date: 3/24/2006
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.385 / Virus Database: 268.3.1/292 - Release
Date: 3/24/2006
| |
|
