gary navarre on wed 3 aug 11
My buddy Peter and I been brainstorming how to get the k=3D
Hey Folks,=3D0A=3D0A=3DA0My buddy Peter and I been brainstorming how to get=
the k=3D
iln over some of those stalling humps around 2000F & 2250F near the end of =
=3D
firing. He suggested getting a tank of oxygen with a regulator and setting =
=3D
it to slowly feed O2 into the coal bed, or in this case the mousehole, for =
=3D
about a half hour to see if it will bring it to temperature. Anybody else e=
=3D
ver think about trying something like this?=3D0A=3D0A=3D0AGary Navarre=3D0A=
Navarre =3D
Pottery=3D0ANavarre Enterprises=3D0ANorway, Michigan, USA=3D0Ahttp://www.Na=
varreP=3D
ottery.etsy.com=3D0Ahttp://www.youtube.com/GindaUP=3D0Ahttp://public.fotki.=
com/=3D
GindaUP/
Fredrick Paget on thu 4 aug 11
Gary,
Don't do it!!
Back in the early days of WWII when I was a little too young to get
drafted and had 2 years of college chemistry under my belt I had a
summer job, night shift at a defence plant near the present siicon
valley, There they were making an ingredient used for making
magnesium for incendary bombs. Called ferrosilicon it was made out of
iron or steel scrap from machine shops mixed with some sand or
something and melted in a giant electric furnace.
After cooking for the planned time they would tap the furnace to
release the molten liquid (like lava) into a depression at the front
of the furnace. To get it started they had to melt a hole in the
correct spot on the side near the bottom of the furnace.
This was done by hooking up a bunch of oxygen tanks in a bank to a 50
foot long length of iron pipe about 1 inch in diameter. A guy with an
acetylene torch heated up the end of the pipe. They turned on the ox
and and the pipe itself began to burn with a mighty flame. This was
poked into the side of the furnace and it melted the plug in the exit
hole and out came a gush of lava to form a big puddle of molten
lava-like ferrosilicon. They burned up 20 or 30 feet of that pipe in
the process.
Now it was my turn. Wearing an asbestos outfit and a helmet I
approached the lava close enough to get a sample for analysis. I had
a 2 inch diameter carbon rod mounted on a 10 foot long pipe and
dipped it into the lava and then got out of there. The radiated heat
was intense.
The adherant on the carbon rod cooled and cracked off and my job was
to take it over to the lab and run a routine analysis on it and
report back if the batch was good or not.
So look out if you put a metal rod up the mouse hole. Oxygen can
burn up the pipe and wreck the mouse hole. You should keep back 20
feet or so and wear your asbestos suit if you try it.
Fred
--
Twin Dragon Studio
Mill Valley, CA, USA
Craig Edwards on thu 4 aug 11
I would suggest a good kiln design and skillful stoking as the natural
answer. When does a wood fire cease to be a wood fire?
I see wood firing as a natural and kindest way to my finish pots.
Introducing contrivances seems clever at the outset but nature almost alway=
s
seems to trump me in producing healthy and vibrant pots.
But YMMV...
--
Make Good Pots
~Craig
New London MN
http://woodfiredpottery.blogspot.com/
On Thu, Aug 4, 2011 at 12:00 AM, gary navarre
wrote:
> My buddy Peter and I been brainstorming how to get the k
> Hey Folks,
>
> My buddy Peter and I been brainstorming how to get the kiln over some of
> those stalling humps around 2000F & 2250F near the end of firing. He
> suggested getting a tank of oxygen with a regulator and setting it to slo=
wly
> feed O2 into the coal bed, or in this case the mousehole, for about a hal=
f
> hour to see if it will bring it to temperature. Anybody else ever think
> about trying something like this?
>
>
> Gary Navarre
> Navarre Pottery
> Navarre Enterprises
> Norway, Michigan, USA
> http://www.NavarrePottery.etsy.com
> http://www.youtube.com/GindaUP
> http://public.fotki.com/GindaUP/
>
Liz Gowen 1 on thu 4 aug 11
GARY NO NO NO I almost hesitated sending this to the list. . The O2 in =3D
the
air is 21% and more than enough for fire without causing an explosive
situation. Try a belows like they used in the old fireplaces or perhaps =3D
a
hair dryer which I sometimes use on my big green egg bar b q grill. I am
sure some of the wood firers can help with how to introduce air more
passively, but please don't use O2. We would still like to be able to =3D
hear
from you......Liz Gowen
My buddy Peter and I been brainstorming how to get the k Hey Folks,
=3DA0My buddy Peter and I been brainstorming how to get the kiln over some =
=3D
of
those stalling humps around 2000F & 2250F near the end of firing. He
suggested getting a tank of oxygen with a regulator and setting it to =3D
slowly
feed O2 into the coal bed, or in this case the mousehole, for about a =3D
half
hour to see if it will bring it to temperature. Anybody else ever think
about trying something like this?
Gary Navarre
Navarre Pottery
Navarre Enterprises
Norway, Michigan, USA
http://www.NavarrePottery.etsy.com
http://www.youtube.com/GindaUP
http://public.fotki.com/GindaUP/
James Freeman on thu 4 aug 11
On Thu, Aug 4, 2011 at 1:00 AM, gary navarre
wrote:
My buddy Peter and I been brainstorming how to get the kiln over some of
those stalling humps around 2000F & 2250F near the end of firing. He
suggested getting a tank of oxygen with a regulator and setting it to slowl=
y
feed O2 into the coal bed, or in this case the mousehole, for about a half
hour to see if it will bring it to temperature. Anybody else ever think
about trying something like this?
Gary...
The wood kiln I used to fire at the college had two big stall points at
around 1400 F and 2100F, which I understand is pretty common. I have been
told that these two points are where the actual chemical reactions involved
in burning wood change due to temperature, but cannot attest to this.
Ordinarily, we would just keep fighting, stoking, and playing with dampers
for an hour or so, at which point the kiln would somehow "wake up" and star=
t
climbing again. One time, out of frustration, I put the hose from a shop
vac into the exhaust port, and used it to blow air into the mouse holes to
burn up some of the coal bed and to try to raise the temperature, just as a
blacksmith does with the blower on his forge. It did seem to work, but of
course the plastic shop vac hose could not get close enough to the coals to
be effective for any length of time. If one were to affix a metal tube
several feet long to the shop vac hose, I think the trick would work very
well. Contrary to one warning I received, this process did not blow any
clinkers or kiln crunchies onto any of the wares, as the airstream was quit=
e
diffuse by the time it exited the coal bed.
The oxygen tank idea sounds pretty dangerous to me, being averse, as I am,
to explosions. Sounds kind of like one of those "Hey Earl, hold my beer an=
d
watch this" moments. In any case, it would be a lot more expensive than
just using your shop vac.
Good luck.
...James
James Freeman
"...outsider artists, caught in the bog of their own consciousness, too
preciously idiosyncratic to be taken seriously."
"All I say is by way of discourse, and nothing by way of advice. I should
not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/resources
Michael Wendt on thu 4 aug 11
If I were doing this I would observe several precautions:
1) do not allow the oxygen to permeate clothing or nearby
combustibles. This is a recipe for disaster as welders can
tell you. We always start the gas flame first and then bleed
the oxygen level up a little at a time to create the perfect
blue flame.
2) only bleed oxygen into a kiln that is already firing full
on to avoid explosion. Use a standard oxy-acetylene torch
head if possible and monitor hose temperatures. Shield the
hoses from heat if need be.
3) don't leave it on if you aren't there to watch it.
Industry uses oxygen enhanced flames to great effect, just
think first!
Regards,
Michael Wendt
tony clennell on thu 4 aug 11
Gary, Gary, Gary: This is a common stall in a wood kiln. I would go with th=
e
"less wood more often" practice until you get over the bump.
Bon feu!
Tony
On Thu, Aug 4, 2011 at 9:58 AM, Liz Gowen 1 wrote:
> GARY NO NO NO I almost hesitated sending this to the list. . The O2 in th=
e
> air is 21% and more than enough for fire without causing an explosive
> situation. Try a belows like they used in the old fireplaces or perhaps a
> hair dryer which I sometimes use on my big green egg bar b q grill. I am
> sure some of the wood firers can help with how to introduce air more
> passively, but please don't use O2. We would still like to be able to hea=
r
> from you......Liz Gowen
> My buddy Peter and I been brainstorming how to get the k Hey Folks,
>
> My buddy Peter and I been brainstorming how to get the kiln over some of
> those stalling humps around 2000F & 2250F near the end of firing. He
> suggested getting a tank of oxygen with a regulator and setting it to
> slowly
> feed O2 into the coal bed, or in this case the mousehole, for about a hal=
f
> hour to see if it will bring it to temperature. Anybody else ever think
> about trying something like this?
>
>
> Gary Navarre
> Navarre Pottery
> Navarre Enterprises
> Norway, Michigan, USA
> http://www.NavarrePottery.etsy.com
> http://www.youtube.com/GindaUP
> http://public.fotki.com/GindaUP/
>
Pottery by John on thu 4 aug 11
Gary,
If you need a bit more kick than a shop vac delivers, do you have access to
a leaf blower? In particular, one with a way to vary the output, so a gas
powered one might work better. On another group's discussion someone got a
Ryobi leaf blower that was supposed to work off of the 18 volt battery and
hooked it up to a bench power supply so they could get different speeds to
the motor and vary the output. Might be too mechanized for your aesthetic
though for long term, but good for a small experiment.
Also in that discussion they said they had tried a fan and it didn't work
well because of the way fan blades work kind of stirs up the air. They sai=
d
the squirrel cage type impeller of the leaf blower produced a more
concentrated air stream.
John Lowes
Sandy Springs, Georgia
http://wynhillpottery.weebly.com/
pdp1 on thu 4 aug 11
Hi Gary,
You can increase available Oxygen in the Kiln using a small ducted Fan, in =
a
several inch
wide Iron Pipe or stove Pipe or Clay Pipe or whatever, pulling or pushing i=
n
plain outside
Air...and it can have a Damper, just as a flue for the egress does or just
as any incoming atmosphere does.
O2 is a DiOxide, a suffix - I do not believe there is any such thing as 02
existing by itself or exsting as a Moleculs in the Atmosphere.
O2 would exist as an attatchment of two Oxygen Atoms to some other Atom, as
in CO2, which is Carbon DiOxide.
Are you confusing "O2" with Oxygen?
A Tank of Oxygen would contain 'Oxygen', and no 'O2' suffixes.
Oxygen is "O"
Have fun!
Phil
L v
----- Original Message -----
From: "gary navarre"
To:
Sent: Wednesday, August 03, 2011 10:00 PM
Subject: O2 Bleed In A wood Kiln?
My buddy Peter and I been brainstorming how to get the k
Hey Folks,
My buddy Peter and I been brainstorming how to get the kiln over some of
those stalling humps around 2000F & 2250F near the end of firing. He
suggested getting a tank of oxygen with a regulator and setting it to slowl=
y
feed O2 into the coal bed, or in this case the mousehole, for about a half
hour to see if it will bring it to temperature. Anybody else ever think
about trying something like this?
Gary Navarre
Navarre Pottery
Navarre Enterprises
Norway, Michigan, USA
http://www.NavarrePottery.etsy.com
http://www.youtube.com/GindaUP
http://public.fotki.com/GindaUP/
gary navarre on fri 5 aug 11
Ya Phil, Oxygen. I don't know how a nuclear submarine reactor operator with=
=3D
degrees in earth science and geology and I missed just plain O for Oxygen.=
=3D
We are past 60 now ya know? =3D0A=3D0A=3D0A=3DA0Thanks for all the ideas F=
olks, I'=3D
ll let Peter know the responses. I'm not to hip on the idea myself and hesi=
=3D
tate going through the expense of more equipment when the answer seems to b=
=3D
e back in the basics of design refinement, like adding a couple feet to the=
=3D
stack, or anticipating the stall points and adjusting the stoking pattern =
=3D
to get through them. Someone suggested a couple 3" diameter propane weed bu=
=3D
rners might be of use and I could stick one in the crown blowhole if I wasn=
=3D
't so damned paranoid of things that could explode.=3D0A=3D0A=3D0A=3DA0I li=
ke the i=3D
dea of rigging up something I can fit onto the mousehole entrance flue to b=
=3D
low air and keep the ash from blocking the opening under the Bourry box. La=
=3D
st firing I used a long metal rod to push the ash out of the way but it rea=
=3D
lly needs more air flow to keep the throat arch clear. Cardew mentioned how=
=3D
important it is to keep the throat arch clear and over stoking can mess th=
=3D
at up real quick. Guess I'll just have to wait and think on this while I co=
=3D
llect more fuel.=3D0A=3D0A=3DA0=3D0AGary Navarre=3D0ANavarre Pottery=3D0ANa=
varre Enterp=3D
rises=3D0ANorway, Michigan, USA=3D0Ahttp://www.NavarrePottery.etsy.com=3D0A=
http:/=3D
/www.youtube.com/GindaUP=3D0Ahttp://public.fotki.com/GindaUP/=3D0A=3D0A=3D0=
A_______=3D
_________________________=3D0AFrom: pdp1 =3D0ATo: Claya=
rt@L=3D
SV.CERAMICS.ORG=3D0ASent: Thursday, August 4, 2011 1:14 PM=3D0ASubject: Re:=
[Cl=3D
ayart] O2 Bleed In A wood Kiln?=3D0A=3D0AHi Gary,=3D0A=3D0A=3D0AYou can inc=
rease avai=3D
lable Oxygen in the Kiln using a small ducted Fan, in a=3D0Aseveral inch=3D=
0Awi=3D
de Iron Pipe or stove Pipe or Clay Pipe or whatever, pulling or pushing in=
=3D
=3D0Aplain outside=3D0AAir...and it can have a Damper, just as a flue for t=
he e=3D
gress does or just=3D0Aas any incoming atmosphere does.=3D0A=3D0A=3D0A=3D0A=
O2 is a Di=3D
Oxide, a suffix - I do not believe there is any such thing as 02=3D0Aexisti=
ng=3D
by itself or exsting as a Moleculs in the Atmosphere.=3D0A=3D0AO2 would ex=
ist =3D
as an attatchment of two Oxygen Atoms to some other Atom, as=3D0Ain CO2, wh=
ic=3D
h is Carbon DiOxide.=3D0A=3D0A=3D0AAre you confusing "O2" with Oxygen?=3D0A=
=3D0AA Tan=3D
k of Oxygen would contain 'Oxygen', and no 'O2' suffixes.=3D0A=3D0A=3D0AOxy=
gen is=3D
"O"=3D0A=3D0A=3D0A=3D0AHave fun!=3D0A=3D0A=3D0APhil=3D0AL v=3D0A=3D0A=3D0A=
----- Original Message=3D
-----=3D0AFrom: "gary navarre" =3D0ATo: yart=3D
@LSV.CERAMICS.ORG>=3D0ASent: Wednesday, August 03, 2011 10:00 PM=3D0ASubjec=
t: O=3D
2 Bleed In A wood Kiln?=3D0A=3D0A=3D0AMy buddy Peter and I been brainstormi=
ng how=3D
to get the k=3D0AHey Folks,=3D0A=3D0AMy buddy Peter and I been brainstormi=
ng how=3D
to get the kiln over some of=3D0Athose stalling humps around 2000F & 2250F=
n=3D
ear the end of firing. He=3D0Asuggested getting a tank of oxygen with a reg=
ul=3D
ator and setting it to slowly=3D0Afeed O2 into the coal bed, or in this cas=
e =3D
the mousehole, for about a half=3D0Ahour to see if it will bring it to temp=
er=3D
ature. Anybody else ever think=3D0Aabout trying something like this?=3D0A=
=3D0A=3D0A=3D
Gary Navarre=3D0ANavarre Pottery=3D0ANavarre Enterprises=3D0ANorway, Michig=
an, US=3D
A=3D0Ahttp://www.NavarrePottery.etsy.com=3D0Ahttp://www.youtube.com/GindaUP=
=3D0Ah=3D
ttp://public.fotki.com/GindaUP/
Paul Haigh on mon 8 aug 11
Some thoughts on stalls- Maintaining is gaining. If the temp is not falling=
, then you are soaking heat into the bricks and this is one step in overcom=
ing a stall.
I agree with Tony- light stokes more frequently. Choking the kiln up with w=
ood/coals is the tendency- you need to burn that out. Switch to the lightes=
t dryest wood that you have- pine etc. if you have it. Throw light stokes n=
ear the throat so that air goes by the wood for efficient small stoking, in=
my limited experience.
How the kiln is stacked can be THE major influence. I had a similar stall, =
as the pots start to shrink it opens up air space. For me, the fire was rac=
ing across the bottom of the kiln and I need to stuff the bottom very tight=
with pots and looser up top. I am moving toward shorter shelves to allow m=
ore space for flame movement and a row of taller pots to act as a bagwall u=
p front because pots in the bottom back got no lovin at all.
Last- look for places to seal up. Put a strong light in the kiln. Any gaps =
are places for air to get sucked in so that you aren't directing air effici=
ently through the firebox. A chimney that's way too lose is like having pas=
sive dampers.
Best of luck
Paul Haigh
Wiley Hill Mudworks
Web: http://wileyhill.com
Facebook: http://www.facebook.com/pages/Wiley-Hill-Mudworks/108145139230652
etsy: http://www.etsy.com/shop/WileyHillMudworks
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