gary navarre on mon 27 jul 09
Hay Doug, this is probably what you are looking for...=3D0A=3D0Ahttp://mono=
cacy=3D
pottery.com/kiln/kiln.htm=3D0A=3D0A=3D0A=3D0A--- On Mon, 7/27/09, Doug Trot=
t tt@GMAIL.COM> wrote:=3D0A=3D0A> From: Doug Trott =3D0A> =
Subjec=3D
t: [Clayart] Wood/Salt kiln construction=3D0A> To: Clayart@LSV.CERAMICS.ORG=
=3D
=3D0A> Date: Monday, July 27, 2009, 12:34 PM=3D0A> I am in the final (I hop=
e) s=3D
tages of=3D0A> designing a kiln, and would appreciate=3D0A> thoughts on som=
e to=3D
pics.=3DA0 The kiln is to be a catenary=3D0A> arch similar to the=3D0A> Man=
ibigam=3D
a of John Theis and Bill van Gilder, and will be=3D0A> fired to cone 10=3D0=
A> w=3D
ith light salt (at least that's the plan).=3D0A> =3D0A> 1.=3DA0 I've had cl=
ipper =3D
3000 hard bricks recommended to=3D0A> me.=3DA0 Are they a good=3D0A> choice=
?=3DA0 T=3D
hink I should coat them - perhaps with a=3D0A> shino glaze?=3D0A=3D0A Sound=
s like=3D
those brick might take 3000=3DB0F. I think mine are good to 2700=3DB0 whic=
h is=3D
enough for what I'm doing. I don't think it is a good idea to coat with Sh=
=3D
ino but to me a thin coat of EPK extra alumina hydrate kiln wash would keep=
=3D
the surface from glazing over and dripping boogers.=3D0A=3D0A> 2.=3DA0 Wha=
t do y=3D
ou like to use for mortar, what=3D0A> consistency, and how applied?=3D0A> W=
ater=3D
y enough to dip, or thick enough to spread by=3D0A> hand?=3DA0 Do you morta=
r=3D0A=3D
> everything, including the floor?=3D0A=3D0A I used both on the Hobagama, j=
ust =3D
depends on where I was working. My floor was set dry and pitched on edge on=
=3D
a bed of gravel with a half inch of fireclay. =3D0A=3D0A=3D0A> 3.=3DA0 Is =
there a =3D
rule of thumb for estimating the number=3D0A> and type (straight or=3D0A> a=
rch)=3D
of bricks needed for the catenary arch?=3DA0 I'm=3D0A> thinking that I can=
=3D0A>=3D
estimate the interior and exterior arc lengths, divide the=3D0A> exterior =
by=3D
2.5"=3D0A> to come up with a number of bricks, and then from there=3D0A> d=
eter=3D
mine how many=3D0A> would have to be arches to get down to the length of th=
e=3D
=3D0A> interior arc.=3DA0 Is=3D0A> there a better way?=3D0A=3D0A Instead of=
buying sm=3D
all quantities of #1, #2, arches or feathered bricks I bought 3 pallets of =
=3D
9" straights (456 on a pallet) and set the angled bricks with extra lag on =
=3D
the outside edge. My lag mix was roughly 50/50 EPK and/or fireclay with 10%=
=3D
kyanite/mullite or fine grog. For large voids like rounding the front and =
=3D
connecting the stack I'd mix castable and wet lag to fill the gap. However,=
=3D
by the looks of the design you intend to use compounded curves will not be=
=3D
involved. Good luck and stay in there eh!=3D0A=3D0A=3D0A> =3D0A> Thanks fo=
r the he=3D
lp!=3D0A> =3D0A> Doug=3D0A>=3D0A=3D0A =3D0AGary Navarre=3D0ANavarre Pottery=
=3D0ANavarre Ent=3D
erprises=3D0ANorway, Michigan, USA=3D0Ahttp://www.youtube.com/GindaUP=3D0Ah=
ttp://=3D
public.fotki.com/GindaUP/ =3D0A=3D0A=3D0A
douglas fur on mon 27 jul 09
In my lights I'd puchase chain to generate the cat curves that has links
which have a multiple of 2.5". Being me I'd be tempted to make a jig and
form my own 2.5" links but normal people probably wouldn't go that far.
DRB
Seattle
On Mon, Jul 27, 2009 at 10:34 AM, Doug Trott wrote:
> I am in the final (I hope) stages of designing a kiln, and would apprecia=
te
> thoughts on some topics. The kiln is to be a catenary arch similar to th=
e
> Manibigama of John Theis and Bill van Gilder, and will be fired to cone 1=
0
> with light salt (at least that's the plan).
>
> 1. I've had clipper 3000 hard bricks recommended to me. Are they a good
> choice? Think I should coat them - perhaps with a shino glaze?
> 2. What do you like to use for mortar, what consistency, and how applied=
?
> Watery enough to dip, or thick enough to spread by hand? Do you mortar
> everything, including the floor?
> 3. Is there a rule of thumb for estimating the number and type (straight
> or
> arch) of bricks needed for the catenary arch? I'm thinking that I can
> estimate the interior and exterior arc lengths, divide the exterior by 2.=
5"
> to come up with a number of bricks, and then from there determine how man=
y
> would have to be arches to get down to the length of the interior arc. I=
s
> there a better way?
>
> Thanks for the help!
>
> Doug
>
jonathan byler on mon 27 jul 09
HI doug,
I guestimated everything by using adobe illustrator on the computer as
a primitive cad program. made the shapes of all the bricks and
started stacking stuff together on the computer. you could also cut
and paste by hand using craft paper or roofing felt or something as
patterns, but much more work.
I recommend getting actual samples of the bricks you are going to use
if the dimensional design is at all critical, which in some places it
can be. we have had pretty serious variations in bricks, including
some warpage in the hard bricks. also different arch bricks that are
thicker, and maybe 1/8 to 1/4" longer than others. specifiy
EVERYTHING. a #1 arch is not just a #1 arch.... they come in
different thicknesses, so you need to say #1 arch 2 - 2-1/2 (thickness
at narrowest and widest) x 4-1/2x9 or for the thicker ones, 2-3/4 - 3
x 4-1/2 x 9. I'm sure they make other sizes of #1 arch bricks also.
same taper, but different thickness, affects the curve of the arch in
a big way...
in terms of mortar, we have been using fireclay and fine sand roughly
equal amounts by volume in a scoop, mixed up to a consistency where it
can be troweled on in order to keep the layers flat and also even with
the softbrick exterior (2300K). the softbricks we got are extremely
consistent in size and are for the most part stacked dry, with a bit
of mortar every so often if things get out of level or one side of the
brick is not quite even. don't forget to do a rowlock course every 5
courses between inner and outer layers (unless you are doing fiber or
castable outer layer). we staggered them in an odd way, instead of a
standard row lock course, partly for looks, partly because it used
less hardbrick, but seemed to still be as strong a wall.
I put mortar in the floor, although I laid everything dry, first to
layers of softbrick overlapping, then a layer of hardbrick with the
mortar between. I'm sure cracks will open up eventually but I didn't
want to encourage the soda/salt to work their way down between the
cracks. I have been washing off the excess mortar, again mostly for
looks, but it also allows me to compact it in the spaces between the
bricks a bit better. Again, I'm sure it will move some as it is
fired, but I need things too look good, since the safety people and
the facilities people are more impressed by the already safe kiln when
it looks nice and as though care has gone into making it (which it
has). on a catenary arch kiln, I don't know how much you would want
to mortar things due to chunks falling from the ceiling. I am putting
no mortar in the arch on our sprung arch kiln. I suppose the glaze
sprayed inside will probably help keep down some of the possibility of
chunks falling out, but I have no experience with this as of yet. Not
sure which shino glaze to use yet either, but will cross that bridge
when we get to it. someone else, like vince pitelka will surely know.
One last piece of advice that I got from hank in eugene: if you make
your fireboxes a bit larger than needed, you can make a castable
lining (back it up with thin layer of fiber for easier removal). if
you only put the salt/soda charge in the firebox, it will be less
likely to eat up the floor other places since it will puddle there
until it vaporizes. when the lining wears out, simply chip it out and
make a new one. Might want to make it about 1" deep below the burner
ports so that you don't have anything dripping out the burner ports.
by the way, the conventional wisdom is just to use good old empire-s
hardbricks or the equivalent. accroding to vince, high alumina bricks
tend to spall more, despite being more resistive to attack by the
sodium. probably because they don't fuse over as nicely as the old
empires.
best of luck with this,
jon byler
On Jul 27, 2009, at 12:34 PM, Doug Trott wrote:
> I am in the final (I hope) stages of designing a kiln, and would
> appreciate
> thoughts on some topics. The kiln is to be a catenary arch similar
> to the
> Manibigama of John Theis and Bill van Gilder, and will be fired to
> cone 10
> with light salt (at least that's the plan).
>
> 1. I've had clipper 3000 hard bricks recommended to me. Are they a
> good
> choice? Think I should coat them - perhaps with a shino glaze?
> 2. What do you like to use for mortar, what consistency, and how
> applied?
> Watery enough to dip, or thick enough to spread by hand? Do you
> mortar
> everything, including the floor?
> 3. Is there a rule of thumb for estimating the number and type
> (straight or
> arch) of bricks needed for the catenary arch? I'm thinking that I can
> estimate the interior and exterior arc lengths, divide the exterior
> by 2.5"
> to come up with a number of bricks, and then from there determine
> how many
> would have to be arches to get down to the length of the interior
> arc. Is
> there a better way?
>
> Thanks for the help!
>
> Doug
ivor & olive lewis on tue 28 jul 09
:Dear Doug Trott,
I am intrigued by the thought of providing a corrosion resistant lining by
coating your bricks with a Shino Glaze. This idea has been discussed on
Clayart in earlier times and I am unsure as to whether there were any
results posted to verify the efficiency of this process.
My suggestion would be to find someone who was Salt Glazing on a regular
basis and proved them with a shino coated brick to test. If you can do this
pay particular attention to the corners and the edges. Slicing with a
diamond saw would help to determine the penetration, if any, of the vapour
into the brick structure
If the Shino glaze contained a Potash rich felspar I would anticipate a
reaction with Sodium Chloride leading to fusion in the Cone 6 region
My own experience was that a 50/50 mix of Aluminium Hydrate and Kaolin
worked well and resisted the effects of Sodium Chloride. In particular it
gave protection to Silicon Carbide shelving which will react freely with
Sodium Chloride if unprotected with a high alumina wash.
Dr Ralph Segnit published several papers concerning the corrosive effects o=
f
Sodium Chloride on refractories in the 1950's.
Best regards,
Ivor Lewis,
Redhill,
South Australia
David on tue 28 jul 09
Hello Doug,
I am in the middle stages of building a catenary arch snake kiln. I have a =
lot of pictures at my blog under "new kiln pictures", available here, http:=
//davidmorrisonpike.com/newsnakekiln.html
I estimated the brick count and type by building the arch form and doing an=
example arch using actual bricks and counting how many of each were in the=
example. I will try to get pictures of that part up on the page above tomo=
rrow.
Hope that helps,
Dave
gary navarre on wed 29 jul 09
Hay Folks, guess there is more eh...=3D0A=3D0A=3D0A--- On Wed, 7/29/09, jon=
athan =3D
byler wrote:=3D0A=3D0A> From: jonathan byler @GMA=3D
IL.COM>=3D0A> Subject: Re: [Clayart] Wood/Salt kiln construction=3D0A> To: =
Clay=3D
art@LSV.CERAMICS.ORG=3D0A> Date: Wednesday, July 29, 2009, 6:36 PM=3D0A> Do=
ug,=3D
=3D0A> =3D0A> Are you talking about a gap because the damper itself is so=
=3D0A> m=3D
uch=3D0A> thinner than the thickness of a layer of brick?=3D0A=3D0A I used =
a laye=3D
r of soaps to adjust for the shelf thickness...=3D0A=3D0A> =3D0A> I don't k=
now if=3D
you have a brick saw, but we are making the=3D0A> damper=3D0A> pretty airt=
ight=3D
on ours.=3DA0 invovles some cutting and=3D0A> fitting, but no=3D0A> big de=
al.=3DA0=3D
you can get fiber board covered with ITC=3D0A> and use that as a=3D0A> dam=
per,=3D
but it is going to cost you.=3DA0 you.=3DA0 if=3D0A> you have a brick=3D0A=
> suppli=3D
er local, or even one who doesn't rip you off for=3D0A> shipping=3D0A> (lar=
kin =3D
in GA has been good to us in that regard), they may=3D0A> have all=3D0A> ki=
nds =3D
of wild shapes that you can use to make the slot for=3D0A> the damper=3D0A>=
the=3D
right size.=3DA0 we got a couple of 4.5x2.5x18 inch=3D0A> bricks to use as=
a=3D
=3D0A> lintle to allow for wider damper.=3DA0 I am going to cut=3D0A> some =
bricks=3D
down=3D0A> on our brick saw so that the layer of bricks where the=3D0A> da=
mper=3D
slides=3D0A> in is only a little thinker than the damper itself.=3D0A=3D0A=
Odd sh=3D
apes cost a bundle so I learned to make do with standards and cut to fit wi=
=3D
th a hammer & chisel. Truth is I didn't really do enough cutting in the end=
=3D
to justify a brick saw. =3D0A=3D0A> =3D0A> for your keystone, I like real =
bricks=3D
if you can get them=3D0A> over=3D0A> castable, but it is only out of conve=
nien=3D
ce.=3DA0=3D0A> castable, if you buy the=3D0A> commercial stuff is pretty ex=
pensiv=3D
e, and a lot more work,=3D0A> so if you=3D0A> can get your supplier to sell=
you=3D
bricks that will work, I=3D0A> would go=3D0A> with that.=3DA0 if money is =
an iss=3D
ue, you can make your=3D0A> own castable,=3D0A> there are mixes available o=
n th=3D
e internet if you look, and=3D0A> in some of=3D0A> the kiln books.=3DA0 wit=
h DIY =3D
castable you probably have=3D0A> to pre-fire these=3D0A> sections, though t=
o ke=3D
ep them from shrinking.=3DA0 there=3D0A> is also the=3D0A> question of how =
well y=3D
our homemade castable will hold up in=3D0A> the harsh=3D0A> wood/soda envir=
onme=3D
nt, and whether it will have a tendency=3D0A> to spall,=3D0A> etc.=3DA0 I'm=
sure =3D
someone has made it funciton, but for=3D0A> how much work.=3D0A> time equal=
ling=3D
money and all... things can get pretty=3D0A> expensive even=3D0A> though y=
ou h=3D
aven't shelled out a dime.=3D0A=3D0ACastable was about $35 for 50lbs. and l=
ag w=3D
as about $6-8 so I wet the castable with lag slurry and filled in shapes I =
=3D
didn't want to cut to fit, or cut to almost fit and finish off with the fil=
=3D
l. The castable will reduce the shrinkage of the thicker sections of lag an=
=3D
d sets up hard in a few hours so you can keep working.=3D0A=3D0A> =3D0A> -j=
on=3D0A=3D
=3D0A As to expenses, I wonder if it is bad form to say how much it cost...=
a=3D
lthough there was that black guy in D.C. a couple years ago that spent 60 g=
=3D
rand of his retirement from the government to have a kiln built and started=
=3D
selling pots in some gallery right away so I guess in must be OK. I haven'=
=3D
t got the total numbers yet but three pallets of hard brick was about $2,10=
=3D
0., Maybe another $1800 in fireclay, tools, new shelves... and the trips to=
=3D
go down below a few times to get about 500 bricks and studio materials fro=
=3D
m storage so I guess I'd have to say I built this kiln for under 5 grand bu=
=3D
t it has taken 5 years, maybe more if I figure in meditation time... oh, ya=
=3D
, and that 12 year drunk I had to go on. There's a hell of a lot more to th=
=3D
is kiln building that I thought when I was a kid and made a pile of bricks =
=3D
and built a fire just to see what happens to the flame. Maybe one of these =
=3D
days I'll learn how to schmooze the clientele. =3D0A=3D0AGary Navarre=3D0AN=
avarre=3D
Pottery=3D0ANavarre Enterprises=3D0ANorway, Michigan, USA=3D0Ahttp://www.y=
outube=3D
.com/GindaUP=3D0Ahttp://public.fotki.com/GindaUP/=3D0A=3D0A=3D0A
gary navarre on wed 29 jul 09
So Doug, guess you have also looked at what I've done with the Hobagama but=
=3D
to make it a bit easier to find the details you ask about below I'll add t=
=3D
hem where needed...=3D0A=3D0A=3D0A--- On Wed, 7/29/09, Doug Trott GMAIL.=3D
COM> wrote:=3D0A=3D0A> From: Doug Trott =3D0A> Subject: =
Re: [C=3D
layart] Wood/Salt kiln construction=3D0A> To: Clayart@LSV.CERAMICS.ORG=3D0A=
> Da=3D
te: Wednesday, July 29, 2009, 3:14 PM=3D0A> I appreciate all the responses,=
..=3D
.Here are a=3D0A> couple more questions:=3D0A> =3D0A> > What are your thoug=
hts ab=3D
out the "keystone" for a=3D0A> catenary arch?=3DA0 Do you=3D0A> use castabl=
e, or =3D
bricks?=3DA0 Strong feelings either way?=3D0A=3D0Ahttp://public.fotki.com/G=
indaUP=3D
/ca/kpap/uph08pov/=3D0A=3D0A... that first page takes you right up to key-s=
toni=3D
ng, I cut brick to fit and also used castable/lag mix. =3D0A=3D0A> > And ch=
imne=3D
y dampers - I've seen kiln shelves used, and=3D0A> a slot left in the=3D0A>=
chi=3D
mney for the shelf to be slid in and out.=3DA0 Seems=3D0A> like a large gap=
is=3D
=3D0A> created though, meaning that I get a passive damper, too,=3D0A> whic=
h I =3D
don't=3D0A> really want.=3DA0 What have you done to avoid a large=3D0A> gap=
?=3DA0 D=3D
o you change the=3D0A> chimney cross-section at that point or do anything e=
ls=3D
e to=3D0A> try to mitigate=3D0A> the effect of the gap?=3D0A=3D0A Ya, there=
is an a=3D
ir slit above the damper which should be a little loose on the fit to adjus=
=3D
t to expansion but it can be blocked with a soap and a couple pieces of spl=
=3D
its. This kiln has four passive damper holes up the stack, an active shelf =
=3D
damper, and I'll fool around with a chimney cap damper or something with ho=
=3D
les in the bricking to allow air to the top of the stack to dilute the smok=
=3D
e.=3D0A=3D0A Here is some video on the thinking for setting up the damper a=
nd a=3D
demonstration of using the castable/lag...=3D0A=3D0Ahttp://www.youtube.com=
/my_=3D
playlists#=3D0A=3D0Ahttp://www.youtube.com/my_playlists#=3D0A=3D0A... and t=
he brick=3D
by brick shots...=3D0A=3D0Ahttp://public.fotki.com/GindaUP/ca/kpap/uphbgam=
a08d=3D
argf/=3D0A=3D0A Maybe you cam modify some of these ideas to fit the design =
you =3D
have in mind. I guess I got lucky in having a bunch of other refractory sha=
=3D
pes around besides just standard hard brick so I could custom fit better.=
=3D
=3D0A =3D0A> =3D0A> Thanks!=3D0A> =3D0A> Doug=3D0A> =3D0A> On Tue, Jul 28, =
2009 at 5:41 P=3D
M, gary navarre=3D0A> wrote:=3D0A> =3D0A> > I=
'll ad=3D
d this must be the logic behind my giving my=3D0A> furniture a thin coat=3D=
0A> =3D
> of kiln wash all around for use in the wood kiln=3D0A> because ash is als=
o=3D
=3D0A> > corrosive over time...=3D0A=3D0A One drawback some folks might not=
like =3D
with this kiln at first would be crawling on their knees to load but it is =
=3D
not that inconvenient if I wear roofers knee pads with hard caps. This cham=
=3D
ber is 65cu.ft. and if I built it big enough to stand in I'd need a grant a=
=3D
nd another lifetime to load so this size shape works for me. Besides, it ge=
=3D
ts me into doing halfassed prostrations again and it's a lot more comfortab=
=3D
le than the first version.=3D0A=3D0A Good luck and stay in there eh!=3D0A=
=3D0AGary =3D
Navarre=3D0ANavarre Pottery=3D0ANavarre Enterprises=3D0ANorway, Michigan, U=
SA=3D0Ah=3D
ttp://www.youtube.com/GindaUP=3D0Ahttp://public.fotki.com/GindaUP/=3D0A=3D0=
A=3D0A =3D
David on thu 30 jul 09
I agree with whoever wrote about getting an airtight fit on the damper. My =
=3D
damper isn't totally air tight but more than sufficient.
I try not to use castable for a keystone brick or what ever it is called. I=
=3D
try to get the arch right but I am hardly scientific about it so on the th=
=3D
ree arches I have built one has needed castable for the top and the other t=
=3D
wo haven't.
I posted the pictures I referred to last post so if you want to have=3DA0 a=
l=3D
ook see here you are, on page 2
http://davidmorrisonpike.com/newsnakekiln.html
=3DA0When I hit reply=3DA0 I can no longer see the messages so I don't reme=
mber=3D
who wrote what.=3D20
Dave
| |
|
