William & Susan Schran User on fri 15 jun 12
On 6/15/12 5:57 PM, "Tony Lilly" wrote:
>Hi all,
>
>I'm new to this, so forgive me if this is a question with an obvious
>answer.
>
>I fired a batch of pottery (just test pieces, but a lot of them) with ^6
>crystalline glazes, and I got an Error 1 on the Skutt Kilnmaster
>controller
>on the kiln. I still hit cone 6, according to the guard cones, but
>according to the very helpful technician at Skutt, the kiln probably shut
>off near the top temp (2210 F) and didn't cool properly. I got no (or
>very
>few) tiny crystals, which might confirm a rapid cool with no soaks (though
>as novice I might have had other problems, too).
>
>My question is this: can I refire the same pieces, as they currently are,
>in
>a corrected (or different) kiln, this time using the proper cooling
>cycle?
>Do I need to add more raw glaze to each piece (which would mean mixing new
>batches of glaze-- a real pain since there were about 40 different recipes
>being tested)? Or are these test pieces just done for?
>
>The recipes were mostly based on Bill Schran's MFE/revised Turnidge
>recipe,
>if that makes a difference.
Tony,
Just go ahead and re-fire with your intended cooling program.
The error message points to older elements that can't maintain a fast
programmed heat rise, so you probably need to slow that down. Also
wouldn't hurt to slow the firing down to 100 - 130F per hour from 2000F to
your final 2210F, but do put in new cones. I found by slowing down at the
top temps my end point was 2195F.
Let me know if you have any other questions.
Be interested in seeing the results of your tests.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Tony Lilly on fri 15 jun 12
Hi all,
I'm new to this, so forgive me if this is a question with an obvious answ=
=3D
er.
I fired a batch of pottery (just test pieces, but a lot of them) with ^6
crystalline glazes, and I got an Error 1 on the Skutt Kilnmaster controll=
=3D
er
on the kiln. I still hit cone 6, according to the guard cones, but
according to the very helpful technician at Skutt, the kiln probably shut=
=3D
off near the top temp (2210 F) and didn't cool properly. I got no (or ve=
=3D
ry
few) tiny crystals, which might confirm a rapid cool with no soaks (thoug=
=3D
h
as novice I might have had other problems, too).
My question is this: can I refire the same pieces, as they currently are,=
=3D
in
a corrected (or different) kiln, this time using the proper cooling cycle=
=3D
?=3D20
Do I need to add more raw glaze to each piece (which would mean mixing ne=
=3D
w
batches of glaze-- a real pain since there were about 40 different recipe=
=3D
s
being tested)? Or are these test pieces just done for?
The recipes were mostly based on Bill Schran's MFE/revised Turnidge recip=
=3D
e,
if that makes a difference.
Thanks so much!
Tony
Snail Scott on sat 16 jun 12
On Jun 15, 2012, at 4:57 PM, Tony Lilly wrote:
> I fired a batch of pottery (just test pieces, but a lot of them) with =3D
^6
> crystalline glazes, and I got an Error 1...can I refire the same =3D
pieces, as they currently are, in
> a corrected (or different) kiln, this time using the proper cooling =3D
cycle?=3D20
> Do I need to add more raw glaze to each piece (which would mean mixing =
=3D
new
> batches of glaze-- a real pain since there were about 40 different =3D
recipes
> being tested)? Or are these test pieces just done for...
So, you reached melt, but did not get the slow=3D20
controlled hold and cool required for crystal growth.=3D20
You can refire them to peak temperature on a very=3D20
fast schedule to minimize the additional heat-work,=3D20
then continue into the cooling cycle as normal, but=3D20
you will still get some extra heat-work. Better to fire=3D20
to just above the temp where your hold cycle starts=3D20
for crystal growth, then proceed with the normal=3D20
cooling cycle. That will be a closer match to what=3D20
should have happened the first time.=3D20
Anyone who has re-fired a matte high-fire glaze to ^06=3D20
in order to add a low-fire glaze has done basically the=3D20
same thing: it acts like a cooling soak and increases=3D20
crystal growth of even microcrystalline glazes. (Glass=3D20
artists call the effect 'devitrification'.) No effect, of course,=3D20
on glazes that are 'true' glossy.
Even so, this will not be a valid test batch, because=3D20
the exact conditions of the test will be different from=3D20
conditions of actual use (unless you plan to re-fire=3D20
everything henceforth). It may give you a ballpark=3D20
notion of color, but there will likely be differences in=3D20
crystal growth, fluidity and everything that is tied to=3D20
duration of firing and cooling. You can come close,=3D20
but it won't be exact.
I assume you are testing so many glazes in order to=3D20
narrow down your selections to just a few for actual=3D20
use. If so, re-firing these tests likely won't be a waste,=3D20
but you will need to follow up with further testing on=3D20
the likely contenders.
Don't re-fire anything until you figure out the cause of=3D20
the error message, though, and correct it.=3D20
-Snail
ronroy@CA.INTER.NET on sat 16 jun 12
Hi Tony,
You don't need to refire all the way - just go to where you usually
start your slow cool - there will already be some extra crystal growth
on the way up so you don't need to cool as slow as you usually do to
get the same crystal growth.
If you do slow cool the same amount you will get bigger crystals.
RR
Quoting Tony Lilly :
> Hi all,
>
> I'm new to this, so forgive me if this is a question with an obvious answ=
er.
>
> I fired a batch of pottery (just test pieces, but a lot of them) with ^6
> crystalline glazes, and I got an Error 1 on the Skutt Kilnmaster controll=
er
> on the kiln. I still hit cone 6, according to the guard cones, but
> according to the very helpful technician at Skutt, the kiln probably shut
> off near the top temp (2210 F) and didn't cool properly. I got no (or ve=
ry
> few) tiny crystals, which might confirm a rapid cool with no soaks (thoug=
h
> as novice I might have had other problems, too).
>
> My question is this: can I refire the same pieces, as they currently are,=
in
> a corrected (or different) kiln, this time using the proper cooling cycle=
?
> Do I need to add more raw glaze to each piece (which would mean mixing ne=
w
> batches of glaze-- a real pain since there were about 40 different recipe=
s
> being tested)? Or are these test pieces just done for?
>
> The recipes were mostly based on Bill Schran's MFE/revised Turnidge recip=
e,
> if that makes a difference.
>
> Thanks so much!
>
> Tony
>
Tony Lilly on tue 19 jun 12
Thank you all for your help! I refired in a different kiln, going through
the whole cycle again, and everything worked out beautifully. I take
Snail's point about the conditions not being the same as a successful fire
the first time around, but I got a good idea of which combinations of
colorants I want to pursue and which recipes need some tweaking. Once I get
some pictures worth sharing, I'll post those, too.
Best,
Tony
On Sat, Jun 16, 2012 at 5:31 PM, wrote:
> Hi Tony,
>
> You don't need to refire all the way - just go to where you usually start
> your slow cool - there will already be some extra crystal growth on the w=
ay
> up so you don't need to cool as slow as you usually do to get the same
> crystal growth.
>
> If you do slow cool the same amount you will get bigger crystals.
>
> RR
>
>
> Quoting Tony Lilly :
>
> Hi all,
>>
>> I'm new to this, so forgive me if this is a question with an obvious
>> answer.
>>
>> I fired a batch of pottery (just test pieces, but a lot of them) with ^6
>> crystalline glazes, and I got an Error 1 on the Skutt Kilnmaster
>> controller
>> on the kiln. I still hit cone 6, according to the guard cones, but
>> according to the very helpful technician at Skutt, the kiln probably shu=
t
>> off near the top temp (2210 F) and didn't cool properly. I got no (or
>> very
>> few) tiny crystals, which might confirm a rapid cool with no soaks (thou=
gh
>> as novice I might have had other problems, too).
>>
>> My question is this: can I refire the same pieces, as they currently are=
,
>> in
>> a corrected (or different) kiln, this time using the proper cooling cycl=
e?
>> Do I need to add more raw glaze to each piece (which would mean mixing n=
ew
>> batches of glaze-- a real pain since there were about 40 different recip=
es
>> being tested)? Or are these test pieces just done for?
>>
>> The recipes were mostly based on Bill Schran's MFE/revised Turnidge
>> recipe,
>> if that makes a difference.
>>
>> Thanks so much!
>>
>> Tony
>>
>>
>
>
>
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