Randall Moody on sun 31 jan 10
On Sun, Jan 31, 2010 at 4:13 PM, Larry Kruzan wro=
te:
> Hi Pat,
> I'm really not trying to be a smartass or anything BUT just how was it
> unusable? Glaze is not milk or soup -
>
> Larry Kruzan
>
I was wondering the same thing myself. Considering that all of the
ingredients for the vast majority of glazes have been in the ground for eon=
s
I don't see how they could be unusable or "spoil". I could understand that
you may not get consistent results from using a very old glaze and then a
very new glaze due to the difference in materials used but if you use an ol=
d
glaze on all of the pieces for a set then your results would be consistent
within that set.
--
Randall in Atlanta
pat gilmartin on sun 31 jan 10
I recently had a problem with some commercial glaze that was out of date wh=
en I bought it. The merchant was unwilling to exchange it (their other stoc=
k of the same glaze was probably out of date too, though). I contacted the =
mfgr. (Amaco), and fortunately, after confirming through the batch number t=
hat the glaze was old, they were nice enough to replace it for me.
My question is: is there any way to decipher these batch numbers or otherwi=
se figure out if the glaze sitting on the merchants' shelves has been there=
for several years? I have no local pottery supply store and must order eve=
rything on line, paying for delivery too, of course. It can become very exp=
ensive (not to mention inconvenient - I needed this glaze to finish a commi=
ssion job) to pay for these products and their delivery, only to find them =
unusable.
Pat Gilmartin
Columbia, SC
Larry Kruzan on sun 31 jan 10
Hi Pat,
I'm really not trying to be a smartass or anything BUT just how was it
unusable? Glaze is not milk or soup - it might be a little thick but it jus=
t
will not spoil. Add a little water and CMC and it good as new.
Perhaps you are using some process I'm not familiar with and so I'll
apologize in advance. I mix all my glazes so that I have control and
originality (to a point).
Larry Kruzan
Lost Creek Pottery
www.lostcreekpottery.com
-----Original Message-----
From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of pat gilmartin
Sent: Sunday, January 31, 2010 11:28 AM
To: Clayart@LSV.CERAMICS.ORG
Subject: purchasing commercial glazes
I recently had a problem with some commercial glaze that was out of date
when I bought it. The merchant was unwilling to exchange it (their other
stock of the same .........
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Snail Scott on mon 1 feb 10
On Jan 31, 2010, at 11:27 AM, pat gilmartin wrote:
> I recently had a problem with some commercial glaze that was out of
> date when I bought it...
I had this happen years ago, also on a tight-deadline
commission. One (just the one) out of several glazes
was failing to melt properly, and the supplier blamed my
firing although everything else was perfect. I contacted
the supplier (Mayco) who told me the codes on the jars
were so old that even they didn't have a record of the
dates anymore, but that particular factory had been
closed for a decade. They speculated that the supplier
had bought up someone else's old stock. Without
attempting to cast further blame, they actually Fed-Exed
me a free case of the new formulation of the same color,
which did indeed arrive the next day. Good for them!
-Snail
Snail Scott on mon 1 feb 10
On Jan 31, 2010, at 5:15 PM, Randall Moody wrote:
>> I'm really not trying to be a smartass or anything BUT just how was
>> it
>> unusable? Glaze is not milk or soup...
Many older commercial glazes had solubles in
their recipes, and didn't age well even when tightly
sealed. (This is what the Mayco technical staff
told me.) These recipes have largely been
discontinued or reformulated to use less soluble
material.
-Snail Scott
Rimas VisGirda on mon 1 feb 10
I'm not sure what would go "out of date" on commercial glazes. I don't use =
them very much and have had glazes and underglazes sitting on my shelves fo=
r 10 years and more in some cases, and they are fine... The only time they =
go "bad" is if the lid is not closed tightly, in which case they get thicke=
r or if sitting long enough get dry. For thickened glazes, just add water. =
For dry glazes, it's a pain but you can break them up and reconstitute with=
water and a little CMC or propylene glycol. My standard practice is to put=
3 marbles into a jar once I open it. Then I can shake it to mix at any lat=
er date, listening for the marbles to click as in a spray paint can. Leavin=
g glaze on the threads of the jar and lid can be problematic by not allowin=
g the lid to seal TIGHT thereby allowing the H2O to evaporate over time. Gl=
aze on the lid also functions as a very good "glue" when trying to unscrew =
a jar some months down the line... -Rimas
C Sullivan on mon 1 feb 10
Mornin' Pat
Many of my commercial glazes (which are on hand here in the studio) are ove=
r
3-years old. Some have solidified. Have discovered that you can
reconstitute them by adding water until they are the right consistency and
they work just fine. In both oxidation and reduction.
If your faucet water has a lot of iron in it, use bottled/purified water
from the store.
Hope this helps.
Chae
On Sun, Jan 31, 2010 at 10:27 AM, pat gilmartin wro=
te:
> I recently had a problem with some commercial glaze that was out of date
> when I bought it.
> I needed this glaze to finish a commission job) to pay for these products
> and their delivery, only to find them unusable.
>
> Pat Gilmartin
> Columbia, SC
>
pat gilmartin on tue 2 feb 10
Thanks to everyone who responded - on-line and off-line - to my original po=
st about a problem with a commercial glaze and question about how to decode=
batch numbers or otherwise find out how old a glaze might be.
I do mostly sculpture,don't use much glaze, and am certainly not an expert =
on them. But I have ordered a few dozen jars over a 6-7 year period and nev=
er encountered the problem I wrote about. The glaze was so stiff that I cou=
ld not push a wooden paint stirrer into it. (The foil seal on the jar was f=
ine - good and tight.) I used a screwdriver to dig out enough glaze to reco=
nstitute with water and do a test tile with. But it seemed to me that a new=
jar of glaze should not be that solid, and I should not have to invest the=
time and labor needed to make it usable for the first time. Thus my contac=
t with the dealer and then the mfgr. to try to get a replacement or refund.
When I contacted the mfgr., they told me that they would stand behind this =
glaze for 2 years (the mfgr. date was encoded in the batch number). The one=
I had bought was almost 3 years old, and so they replaced it for me. The f=
act that the mfgr. has this policy this tells me that this particular glaze=
formula may have problems after some length of time. Based on comments I h=
ave received, such is not the case with all glazes; some last for years wit=
hout any problems.
In any case, the replacement glaze behaved beautifully (thank you, Amaco), =
and my commission job is finished.
Pat Gilmartin
Columbia SC
Chris Leake on thu 4 feb 10
Hey Pat,
On rare occasions I have gotten some glazes that are pretty solid. I have =
found it works best to reconstitute the entire batch, break it up, mix with=
water/CMC gum and sieve until I have a good mix again. Since some glazes =
dry up harder than others this can be a bit of work, but doing anything les=
s doesn't always give you a full mix of all the chemicals (or so it seems t=
o me).
Chris Leake
http://potterybychris.com
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