Donalson on thu 10 apr 03
Enjoying the current thread on salt kilns..would appreciate hearing more =
from Hank on his castable with SS pins and fiber backing. He is always =
at the forefront it seems.
I talked with Lowell Baker 6 months ago or so and he told me that one of =
his new (hardbrick) salt kilns, that they were firing with sawdust, was =
producing ware that had an excellent salt texture. No surprise there, =
however, Lowell said this was being done with just 5 pounds of salt! As =
I recall the conversation, the salt was being introduced with the =
sawdust, essentially being "sprayed" into the kiln, with lots of sawdust =
and air. Lowell was using regular old table salt...very fine grind, =
compared with rock salt, he thought this was likely helping with the =
good salting.
Since talking with Lowell, I have been occassionally trying a similar =
method of salt introduction. I have been mixing a saturated, water/salt =
suspension, (coupla gallons of hot water and alot of salt, jiffy mixed =
and then screened). This salt solution is then sprayed into the kiln =
near ^10. The Gilmore blaster, with a compressor works great. I have =
even found that this solution can be sprayed directly onto a specific =
pot, "pounded" so to speak, with no adverse effects on the piece, and a =
good salting. When a particular pot is zeroed in on and continously =
sprayed for 15 seconds or so, a black area gradually appears at the =
point of impact, and then gradually disappears once the spraying has =
stopped. When the kiln is unloaded there is no negative effect of this =
concentrated spraying, just a nice salt texture. Despite hearing much =
trepidation from the staff at NAU, there have thus far, been no pots =
blown up, or cracked shelves, as a result of this technique. Thus =
far, this spraying technique, has only been used in an old, well salted, =
and deteriorating kiln with lots of residual salt. So the results are =
still somewhat suspect, although from what Lowell has said, and from =
the results I have seen, I believe good results could be expected in a =
new kiln.
From the above, I think that the lifespan of a saltkiln, with a =
hardbrick interior surface, may have it's lifetime considerably extended =
by using alternate ways of introducing the salt and therby greatly =
reducing the amount of salt necessary. Both of the above techniques =
eliminate that molten puddle of salt, that is so damn corrosive in the =
firebox area.
I think Steve Mills mentioned the "French" (or should I say Liberty ?) =
method of salting recently. Setting small, glazed, open containers with =
table salt added, in various places in the kiln. Again this technique =
eliminates the puddle in the firebox.
Wood be interested in what others are thinking along these lines.
Craig AZ
Hank Murrow on thu 10 apr 03
On Thursday, April 10, 2003, at 05:56 PM, Culling wrote:
> Any chance of pics when you construct this kiln? or even of the panels
> , do
> you cast panels in situ or place afterwards? How do you protect joins
> from
> vapours? removable firebox lining sounds perfect!! was wondering that
> way
> myself
> Steph
>
Dear Steph;
The kiln panels are cast in the studio and fired in a large kiln. Then
they are assembled to form the kiln. The joints are separated by 3/16"
Ceramic fiber strips as gaskets. I will keep a good photographic record
as we go along and share at key moments. Right now, we are getting salt
fires on the test panels to assure ourselves that we use the best
materials.the salt pans have been used for 30 years and work a charm.
Hey, where are you down under?
Cheers, Hank in Eugene
Hank Murrow on thu 10 apr 03
On Thursday, April 10, 2003, at 07:43 AM, Donalson wrote:
> Enjoying the current thread on salt kilns..would appreciate hearing
> more from Hank on his castable with SS pins and fiber backing. He is
> always at the forefront it seems.
>
>> From the above, I think that the lifespan of a saltkiln, with a
>> hardbrick interior surface, may have it's lifetime considerably
>> extended by using alternate ways of introducing the salt and therby
>> greatly reducing the amount of salt necessary. Both of the above
>> techniques eliminate that molten puddle of salt, that is so damn
>> corrosive in the firebox area.
> I think Steve Mills mentioned the "French" (or should I say Liberty ?)
> method of salting recently. Setting small, glazed, open containers
> with table salt added, in various places in the kiln. Again this
> technique eliminates the puddle in the firebox.
>
> Wood be interested in what others are thinking along these lines.
>
Hi, Hank here;
At Anderson Ranch in the early 70s, we enjoyed unusual life from our
salt kilns by casting a Greencast 94 'pan' across the whole bottom of
the firebox. It took only half a bag per side, and was impervious to
the molten salt. You could see the salt melt and form a lake, which
would volatilize completely within 20 minutes or so. We used 4# of salt
in two to three saltings for an 80 cu ft hard brick kiln. We made the
'pans' removable by casting them with a strip of ceramic fiber paper
between the brick and the pan on all sides.
Nowadays, I am casting large wall panels around 3/4" thick with
Pryor-Gigge's Phlo-cast 30S, which has 12% Silicon-carbide in the mix.
If cast on a glass-smooth surface, this material comes out glass
smooth. So salt will less readily corrode, since the surface area is
minimized. I reinforce these panels with 400 series alloy stainless
steel "Rib-Tec", which are crimped alloy wires around 1" long. No
cracking from such construction. I have cast domes up to four feet
across with this method, though not yet on a salt or soda kiln. Hope to
get that done soon.
I feel that the combination of large but very thin hard-cast panels
backed up with lots of fiber and block insulation is a sensible way to
go for a vapor glazing kiln. We'll see, and i will report back when we
have some fires on this construction.
Cheers, Hank in Eugene (if that is the forefront)
Culling on fri 11 apr 03
Any chance of pics when you construct this kiln? or even of the panels , do
you cast panels in situ or place afterwards? How do you protect joins from
vapours? removable firebox lining sounds perfect!! was wondering that way
myself
Steph
----- Original Message -----
From: "Hank Murrow"
To:
Sent: Friday, April 11, 2003 3:46 AM
Subject: Re: SALT talk
> On Thursday, April 10, 2003, at 07:43 AM, Donalson wrote:
>
> > Enjoying the current thread on salt kilns..would appreciate hearing
> > more from Hank on his castable with SS pins and fiber backing. He is
> > always at the forefront it seems.
> >
> >> From the above, I think that the lifespan of a saltkiln, with a
> >> hardbrick interior surface, may have it's lifetime considerably
> >> extended by using alternate ways of introducing the salt and therby
> >> greatly reducing the amount of salt necessary. Both of the above
> >> techniques eliminate that molten puddle of salt, that is so damn
> >> corrosive in the firebox area.
>
> > I think Steve Mills mentioned the "French" (or should I say Liberty ?)
> > method of salting recently. Setting small, glazed, open containers
> > with table salt added, in various places in the kiln. Again this
> > technique eliminates the puddle in the firebox.
> >
> > Wood be interested in what others are thinking along these lines.
> >
> Hi, Hank here;
>
> At Anderson Ranch in the early 70s, we enjoyed unusual life from our
> salt kilns by casting a Greencast 94 'pan' across the whole bottom of
> the firebox. It took only half a bag per side, and was impervious to
> the molten salt. You could see the salt melt and form a lake, which
> would volatilize completely within 20 minutes or so. We used 4# of salt
> in two to three saltings for an 80 cu ft hard brick kiln. We made the
> 'pans' removable by casting them with a strip of ceramic fiber paper
> between the brick and the pan on all sides.
>
> Nowadays, I am casting large wall panels around 3/4" thick with
> Pryor-Gigge's Phlo-cast 30S, which has 12% Silicon-carbide in the mix.
> If cast on a glass-smooth surface, this material comes out glass
> smooth. So salt will less readily corrode, since the surface area is
> minimized. I reinforce these panels with 400 series alloy stainless
> steel "Rib-Tec", which are crimped alloy wires around 1" long. No
> cracking from such construction. I have cast domes up to four feet
> across with this method, though not yet on a salt or soda kiln. Hope to
> get that done soon.
>
> I feel that the combination of large but very thin hard-cast panels
> backed up with lots of fiber and block insulation is a sensible way to
> go for a vapor glazing kiln. We'll see, and i will report back when we
> have some fires on this construction.
>
> Cheers, Hank in Eugene (if that is the forefront)
>
>
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