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weather effect on insulating fire bricks (ifb)

updated sun 10 jul 11

 

Barro Cocido on tue 28 jun 11


Hello everybody, I just joined this list and being a new comer to all thi=
=3D
ngs
pottery, I am afraid I will be asking more questions than my fair share
would allow. Here is my first post and first question:

I'd like to fabricate a small propane burning gas kiln based on the one
described in the book "Self Reliant Potter". Since money is actually an=
=3D

issue, I'd like to purchase if possible used refractory bricks, if I can
find them. I located a guy selling used Ins.fire bricks that previously
were part of a pottery gas kiln. His bricks have been exposed to the
elements here in Canada, they are all moldy and look rather porous to me
(have never seen a new IFB in person). Mold set aside, would it be
advisable to purchase IFB that have been exposed to the northern elements=
=3D

for many years?

The other question is, would you build a gas kiln with R23 bricks and fir=
=3D
e
it to cone-10? I have read theR23 bricks have melting temperature of 260=
=3D
0F
but rated only to an operational 2300F maximum.=3D20=3D20

Many tanks

Guillermo

Edouard Bastarache on tue 28 jun 11


Guillermo,

mine is made with G-23 IFBs, but 2 layers.
http://www.youtube.com/watch?v=3D366-7HjQEBs

Gis,

Edouard Bastarache
Spertesperantisto

Sorel-Tracy
Quebec

http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://edouardbastaracheblogs2.blogspot.com/
http://www.facebook.com/edouard.bastarache
http://blogsalbertbastarache.blogspot.com/



----- Original Message -----
From: "Barro Cocido"
To:
Sent: Tuesday, June 28, 2011 1:27 PM
Subject: Weather effect on Insulating Fire Bricks (IFB)


Hello everybody, I just joined this list and being a new comer to all thing=
s
pottery, I am afraid I will be asking more questions than my fair share
would allow. Here is my first post and first question:

I'd like to fabricate a small propane burning gas kiln based on the one
described in the book "Self Reliant Potter". Since money is actually an
issue, I'd like to purchase if possible used refractory bricks, if I can
find them. I located a guy selling used Ins.fire bricks that previously
were part of a pottery gas kiln. His bricks have been exposed to the
elements here in Canada, they are all moldy and look rather porous to me
(have never seen a new IFB in person). Mold set aside, would it be
advisable to purchase IFB that have been exposed to the northern elements
for many years?

The other question is, would you build a gas kiln with R23 bricks and fire
it to cone-10? I have read theR23 bricks have melting temperature of 2600F
but rated only to an operational 2300F maximum.

Many tanks

Guillermo

Steve and Joan Irvine on wed 29 jun 11


Guillermo,

IFB that have been exposed to the northern elements for years should be =3D
fine. My IFB kiln has been through 37 Canadian winters without a shed, =3D
and still works like new.
http://www.steveirvine.com/kiln.html

If there is mould or moss on the bricks it should burn off during the =3D
first firing of the new kiln. However, it's hard of course, to know =3D
exactly if the bricks are ok without seeing them first hand. IFB are =3D
porous to begin with; the numerous air pockets contribute to their =3D
insulation properties.=3D20

It is generally recommended to use R26 bricks as the hot face bricks if =3D
you are firing to cone 10.

Hope this helps,

Steve =3D20

> I located a guy selling used Ins.fire bricks that previously
> were part of a pottery gas kiln. His bricks have been exposed to the
> elements here in Canada, they are all moldy and look rather porous to =3D
me
> (have never seen a new IFB in person). Mold set aside, would it be
> advisable to purchase IFB that have been exposed to the northern =3D
elements
> for many years?
>=3D20
> The other question is, would you build a gas kiln with R23 bricks and =3D
fire
> it to cone-10? I have read theR23 bricks have melting temperature of =3D
2600F
> but rated only to an operational 2300F maximum. =3D20
>=3D20
> Many tanks
>=3D20
> Guillermo

Dan Hill on wed 29 jun 11


Hi Guillermo

My experience with used IFB is that if they have been outside and exposed t=
o
rain, snow and multiple freeze, thaws there is a good chance that their
structural integrity will be damaged.
That said I have used such bricks as backup bricks on a soda kiln with no
problems. As long as they hold together when you pick them up they can be
used when dried out completely.

If you are starting out with gas firing I would suggest that you fire to ^6=
.
You will save on fuel and material costs. You could also consider convertin=
g
an old electric kiln to gas. A good introduction to reduction firing.

Dan Hill
Hill Pottery
Wilno Ont. Canada
^6 soda fired stoneware and porcelain
www.hillpottery.com


> I'd like to fabricate a small propane burning gas kiln based on the one
> described in the book "Self Reliant Potter". Since money is actually an
> issue, I'd like to purchase if possible used refractory bricks, if I can
> find them. I located a guy selling used Ins.fire bricks that previously
> were part of a pottery gas kiln. His bricks have been exposed to the
> elements here in Canada, they are all moldy and look rather porous to me
> (have never seen a new IFB in person). Mold set aside, would it be
> advisable to purchase IFB that have been exposed to the northern elements
> for many years?
>
> The other question is, would you build a gas kiln with R23 bricks and fir=
e
> it to cone-10? I have read theR23 bricks have melting temperature of
> 2600F
> but rated only to an operational 2300F maximum.
>
> Many tanks
>
> Guillermo

ivor and olive lewis on wed 29 jun 11


Dear Guillermo,



Heating RI-23 bricks to 2600F would cause major shrinkage and the joints
would eventually open up.

A problem with bricks that have collected vegetation would be ash. At cone
10 some ash can be quite a strong flux. Expect a shortened working life fro=
m
such reclaimed bricks.

Regards,

Ivor Lewis,
REDHILL,
South Australia

douglas fur on sat 9 jul 11


Guillermo

First off I'd find some one to fire one for you and see what happens.
Or buy a few and build a small kiln and fire it to see what happens.

Besides possible freeze thaw damage (don't dismiss out of hand- they put ai=
r
bubbles into concrete to reduce freeze thaw damage so it might not be an
issue.) I'd look out for salts absorbed with the water.

the 2300 and 2600 ratings are based on continuous use- like a tunnel kiln
that runs all the time. plenty of potters have used 2300 brick for ^9/10

DRB
Seola Creek