Forrest on sun 2 sep 07
I bought a second-hand Olympic raku kiln. It looks like it is in good
shape. It has a low-pressure regulator on it and allows for two bottles of
propane to be used at once, with one held in reserve. I tried it for the
first time yesterday and couldn't get it past 500 degrees F. I had plenty
of gas, both burners were lit but I didn't get enough heat. Anyone have a
clue about this?
I am used to firing a fiber raku kiln with a high-pressure regulator on it,
so I'm stumped. If I change my regulator, I have to change the burners,
don't I?
I appreciate any thoughts anyone has on this.
Rosemary Forrest
forrestpottery@comcast.net
William & Susan Schran User on mon 3 sep 07
On 9/2/07 6:13 PM, "Forrest" wrote:
> I bought a second-hand Olympic raku kiln. It looks like it is in good
> shape. It has a low-pressure regulator on it and allows for two bottles =
of
> propane to be used at once, with one held in reserve. I tried it for the
> first time yesterday and couldn't get it past 500 degrees F. I had plen=
ty
> of gas, both burners were lit but I didn't get enough heat. Anyone have =
a
> clue about this?
>=20
> I am used to firing a fiber raku kiln with a high-pressure regulator on i=
t,
> so I'm stumped. If I change my regulator, I have to change the burners,
> don't I?
I have an Olympic updraft that may be similar to your raku kiln. The burner=
s
supplied with my kiln are probably the same as on yours. These are
inexpensive pipe burners. I had so many issues of back-burning with these
type burners, that may have been related to insufficient gas pressure (mine
was the Baso valve maxed at 1/2lb pressure). I ended up removing the
originals burners and ignition tube and replacing them with venturi burners
and heavy duty thermocouple that I bought from Ward Burner. Now my kiln is =
a
burning monster. I can get from 0 to 1000=B0F in 15 minutes if I don't hold i=
t
back!
First thing I'd check is what size orifice you have in the burner. If you
can contact the person who sold you the kiln, ask if they fired with propan=
e
or natural gas. If you have the wrong size orifice, that may be part of the
problem.
2nd thing - how much gas pressure are you using? I often find folks use too
much pressure. At school, we get the best temperature rise in our raku kiln
(single burner) on 1lb pressure using propane.
In the end, you may find switching out to a better burner may be the best
bet.
--=20
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Forrest on mon 3 sep 07
Thanks, Bill, this is exactly what I suspected. I was hoping to avoid new
burners, but I already have the new gauge and regulator, so... I know the
former owner used propane, as am I, so that's not the issue. I do think I
need new burners. It currently has two, I guess I'll ask Ward what he
suggests. =20
Rosemary
> I have an Olympic updraft that may be similar to your raku kiln. The burn=
ers
> supplied with my kiln are probably the same as on yours. These are
> inexpensive pipe burners. I had so many issues of back-burning with these
> type burners, that may have been related to insufficient gas pressure (mi=
ne
> was the Baso valve maxed at 1/2lb pressure). I ended up removing the
> originals burners and ignition tube and replacing them with venturi burne=
rs
> and heavy duty thermocouple that I bought from Ward Burner. Now my kiln i=
s a
> burning monster. I can get from 0 to 1000=B0F in 15 minutes if I don't hold=
it
> back!
>=20
> First thing I'd check is what size orifice you have in the burner. If you
> can contact the person who sold you the kiln, ask if they fired with prop=
ane
> or natural gas. If you have the wrong size orifice, that may be part of t=
he
> problem.
>=20
> 2nd thing - how much gas pressure are you using? I often find folks use t=
oo
> much pressure. At school, we get the best temperature rise in our raku ki=
ln
> (single burner) on 1lb pressure using propane.
>=20
> In the end, you may find switching out to a better burner may be the best
> bet.
>=20
William & Susan Schran User on mon 3 sep 07
On 9/3/07 1:26 PM, "Forrest" wrote:
> Thanks, Bill, this is exactly what I suspected. I was hoping to avoid new
> burners, but I already have the new gauge and regulator, so... I know the
> former owner used propane, as am I, so that's not the issue. I do think I
> need new burners. It currently has two, I guess I'll ask Ward what he
> suggests.
Marc will probably not want to discuss Olympic gas fired kilns with you
because he thinks so highly of them ;^)
When I spoke with him he about had enough people calling him trying to get
their Olympic gas kiln to work. But I also know other folks who have
Olympics and have gotten them to work ok. I have an image and story about
mine on my web site (address below my signature). I promised Marc I would
not send the burners back and I would make them work.
I bought three of the M-750 burners from Marc and I've also figured out how
to get very even temperatures top to bottom in mine with help from a few
others on this forum.
From your response to another message you wrote about having the gas
pressure wide open. Try firing with a pound or less pressure and see if the
temperature will climb and not stall before you try anything else.
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Rob Haugen on tue 4 sep 07
Rosemary,
What is the model number of the kiln that you purchased? Is the burner
system set up in it's original form? I would suggest checking your
regulator to make sure that it is set for 11 inches water column pressure
and is an adequate size for the BTU rating of your kiln. The hose needs to
be a minimum of 1/2 inch inside diameter. I do not believe that you need a
new set of burners for the kiln. You may want to order a new set of flame
retention tips. We added these about 3 years ago and in testing our burners
with the flame retention tips performed as well as or better than the MR
750. Please do not hesitate to call me if you would like to discuss the
situation further.
Rob Haugen
Olympic Kilns
800-241-4400
----- Original Message -----
From: "Forrest"
To:
Sent: Sunday, September 02, 2007 6:13 PM
Subject: Low pressure raku question
>I bought a second-hand Olympic raku kiln. It looks like it is in good
> shape. It has a low-pressure regulator on it and allows for two bottles
> of
> propane to be used at once, with one held in reserve. I tried it for the
> first time yesterday and couldn't get it past 500 degrees F. I had
> plenty
> of gas, both burners were lit but I didn't get enough heat. Anyone have a
> clue about this?
>
> I am used to firing a fiber raku kiln with a high-pressure regulator on
> it,
> so I'm stumped. If I change my regulator, I have to change the burners,
> don't I?
>
> I appreciate any thoughts anyone has on this.
>
> Rosemary Forrest
> forrestpottery@comcast.net
>
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