primalmommy on fri 15 feb 08
I ask these questions with full awareness that I will one day look back
and say, 'What a dork!"
Thanks in advance for your patience.
And yes, I do have the Jack Troy book (autographed, even.) I got it at a
workshop in '01 and have "highlightered" it up over the years, but a lot
of it seems more complex now that I am actually doing it.
Flashing slips:
UPS brought me 50 pounds of Helmer yesterday. I drove it to school, and
I stayed in the EMU studio until after midnight, mixing a dozen kinds of
flashing slips. Some are EPK, some are helmer, some are shino slips.
Some are partly calcined for use on bisque.
Once again, I find myself with too many variables to be able to sort out
in one lifetime, much less a couple of months.
First: Will the claybody under the slip effect the flashing/color?
I know the "thick or thin" question is a crapshoot... the flat canteen
forms I am making for tests have a clear front and back, so I will do
thick on one side and thin on the other... (even so, direction of the
flame will likely be a factor.)
How thick is thick? Toothpaste? Yogurt? Cream? How thin is thin? Wash?
Brush, dip, spray, try one of each? Is it too chunky to spray? Will
brush strokes show through? I am going to need to make more tests! Stack
them like Yertle the Turtle on wads, maybe,
Stacking:
Looking at anagama pix in Troy's book, I think we're not stacking the
EMU train as tightly as some do, to take advantage of the upper space.
Is it possible to combine shelves and stilts and a type of
tumblestacking? Is there a danger of packing pots too tightly so that
the heat is blocked and the back of the kiln doesn't get hot enough?
Are certain sea shells better than others for using w/ wads? I'm firing
right after our annual foray to the grandparents' digs in Florida, so I
can bring home some nice ridgy ones.
(We don't fire past 10 in front and I doubt I'll get any kind of groovy
drippy anagama effects, but what is there to lose? )
Also: has anybody tried putting small cups of salt or bowls of charcoal
next to pots?
If I wrap salted straw or seaweed around a pot, does that require a
saggar?
OK, that's all I've got for now. Back to the studio...
yours
Kelly in Ohio (where Jeff and my boy scouts are sleeping in the woods in
the snow tomorrow night under a tree branch shelter. Yikes. I'll be
curled up with goosedown pillows, hot cocoa, three cats, a fire in the
woodstove, and Jack Troy ;0)
http://www.primalpotter.com
http://www.primalmommy.com/blog.html
Paul Herman on sat 16 feb 08
Hi Kelly,
I can answer a couple of them. You asked:
> First: Will the claybody under the slip effect the flashing/color?
That depends. If it's put on thinly, it will.
> Is there a danger of packing pots too tightly so that
> the heat is blocked and the back of the kiln doesn't get hot enough?
Definitely yes. We have had problems from blocking the draft with a
too tight load. In our kiln it is especially important to keep the
floor and sides fairly loose, to let the flames get everywhere. The
top and center of the stack we can pack a lot tighter and get away
with it.
Plans for our kiln are on my website.
I hope this helps a little.
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Feb 15, 2008, at 9:50 AM, primalmommy wrote:
> I ask these questions with full awareness that I will one day look
> back
> and say, 'What a dork!"
>
> Thanks in advance for your patience.
>
> And yes, I do have the Jack Troy book (autographed, even.) I got it
> at a
> workshop in '01 and have "highlightered" it up over the years, but
> a lot
> of it seems more complex now that I am actually doing it.
>
> Flashing slips:
>
> UPS brought me 50 pounds of Helmer yesterday. I drove it to school,
> and
> I stayed in the EMU studio until after midnight, mixing a dozen
> kinds of
> flashing slips. Some are EPK, some are helmer, some are shino slips.
> Some are partly calcined for use on bisque.
>
> Once again, I find myself with too many variables to be able to
> sort out
> in one lifetime, much less a couple of months.
>
> First: Will the claybody under the slip effect the flashing/color?
>
> I know the "thick or thin" question is a crapshoot... the flat canteen
> forms I am making for tests have a clear front and back, so I will do
> thick on one side and thin on the other... (even so, direction of the
> flame will likely be a factor.)
>
> How thick is thick? Toothpaste? Yogurt? Cream? How thin is thin? Wash?
> Brush, dip, spray, try one of each? Is it too chunky to spray? Will
> brush strokes show through? I am going to need to make more tests!
> Stack
> them like Yertle the Turtle on wads, maybe,
>
> Stacking:
>
> Looking at anagama pix in Troy's book, I think we're not stacking the
> EMU train as tightly as some do, to take advantage of the upper space.
> Is it possible to combine shelves and stilts and a type of
> tumblestacking? Is there a danger of packing pots too tightly so that
> the heat is blocked and the back of the kiln doesn't get hot enough?
>
> Are certain sea shells better than others for using w/ wads? I'm
> firing
> right after our annual foray to the grandparents' digs in Florida,
> so I
> can bring home some nice ridgy ones.
>
> (We don't fire past 10 in front and I doubt I'll get any kind of
> groovy
> drippy anagama effects, but what is there to lose? )
>
> Also: has anybody tried putting small cups of salt or bowls of
> charcoal
> next to pots?
>
> If I wrap salted straw or seaweed around a pot, does that require a
> saggar?
>
> OK, that's all I've got for now. Back to the studio...
>
tony clennell on sat 16 feb 08
tony writes:
Yikes Kelly, I know you know the chorus to the little train that
could but holy moses to be testing in a small wood kiln a few months
before a show is in my mind betting the family farm. I've been wood
firing for almost 3 decades and there is no way i would count on one
firing for a show. That said I'll answer some questions but I think
you should maybe think about what you said "> Once again, I find
myself with too many variables to be able to sort out
> in one lifetime, much less a couple of months."
With wood firing there are enough variables to make a Phd disseration
on each seemingly small thing. If you're going ahead with this I would
want to narrow my selection of variables and not increase them. - one
body, one slip, one glaze etc.
Question #1
> First: Will the claybody under the slip effect the flashing/color?
Tony writes:You know the answer to this! If body affects glaze why
wouldn't it affect a flashing slip?
Question #2
> I know the "thick or thin" question is a crapshoot... the flat canteen
> forms I am making for tests have a clear front and back, so I will do
> thick on one side and thin on the other... (even so, direction of the
> flame will likely be a factor.)
Tony writes: Direction of flame and stacking is a Phd thesis on it's
own. Tumblestacking done well takes hours to load a kiln. Take a
pencil and place it on your keyboard and pretend the screen is the
firebox. Stand the pencil up and ya got your ordinary wood fired
look- ash on one side and not on the other. You get a two sided pot.
Take the pencil and lay it on the keyboard on it's side and on a
diagonal. Fire the firebox screen. Now stand the pencil up. This will
have a very interesting pattern on all sides of the pencil. More ash
close to the screen, less at the back, uneven flashing underneath. In
my opinion a much more interesting visual.
Question #3
> How thick is thick? Toothpaste? Yogurt? Cream? How thin is thin? Wash?
> Brush, dip, spray, try one of each? Is it too chunky to spray? Will
> brush strokes show through? I am going to need to make more tests! Stack
> them like Yertle the Turtle on wads, maybe,
tony writes: It depends on the slip, glaze or the effect you want. A
wash is usually skim milk, a slip is usually 2% cream and a glaze
like shino can be thick like yogurt.
Question #4
> Stacking:
>
> Looking at anagama pix in Troy's book, I think we're not stacking the
> EMU train as tightly as some do, to take advantage of the upper space.
> Is it possible to combine shelves and stilts and a type of
> tumblestacking? Is there a danger of packing pots too tightly so that
> the heat is blocked and the back of the kiln doesn't get hot enough?
tony writes:
Sure ya can. We often tumble stack the front of the train where it is
a battle zone of ash and flash and since Sheila makes boxes and such
we use shelves mid train, then tummblestack the back and stoke on top
of those pots(usually mine) and then shelves again near the flue. You
will find that you may like the undersides of your work more than the
ashy tops.
Question #5
> Are certain sea shells better than others for using w/ wads? I'm firing
> right after our annual foray to the grandparents' digs in Florida, so I
> can bring home some nice ridgy ones.
Tony writes:
Sea shells are over used in wood firing. I don't live by the sea so
don't use them. The ones with the big ridges are nice though.
Question #6
>
> (We don't fire past 10 in front and I doubt I'll get any kind of groovy
> drippy anagama effects, but what is there to lose? )
Tony writes: It ain't the temp that will give you the anagama effects-
it's the time. If you and your buddy are willing to do the crime then
ya have to be willing to do the time.
>
> Also: has anybody tried putting small cups of salt or bowls of charcoal
> next to pots?
Tony writes: Yes, to both. If you use small cups of salt for some salt
flashing make sure they are high fired "glazed "cups or the salt will
eat right thru the clay and your shelves will be fungoooed. Your profs
will be severely pissed.
Charcoal this can be added like John did at the end of a firing for
some Bizen flashing effects. this is a acquired taste and not for the
those that like pretty.
>
> If I wrap salted straw or seaweed around a pot, does that require a
> saggar?
>
Tony writes:
Salted straw is often laid between stacked bowls for a flashing
effect. I think it is problably best where it is protected but this is
one thing i've never down. I guess I never cared for the string look.
Tony writes: Well Kelly you're spooking the horses and you're scaring
me. Best of luck with all this and if I can help in any way I'd be
glad to. I'm sure the other woodies will have more to add.
In the meantime, bon feu!
Tony
Dannon Rhudy on sat 16 feb 08
Kelly asked a bunch - I'll try to answer a
few:
In my experience, the clay body does indeed
affect the flashing slips. Porcelain bodies, for
instance, seem to promote a paler, more delicate
color. My experience. And, you'll see it yourself
where the slip goes from thick to thinner in a
brushstroke.
Thick - between yogurt and heavy cream. You
want it to be brushable or squeezable or throwable.
A bottle with a tip can make some nice marks, and
a container to slosh it on works well sometimes, too.
As to small bowls of salt - many salt firerers do that,
some interesting effects, I've done it. Salted straw and/
or seaweed? The effects burn off at high temps, unless
there is a huge amount of salt. Charcoal burns
up/out at high temps, unless you put the piece in a saggar.
Then, you can get some dynamite effects. Hate to
say "try it", but - that's the only way to find out.
I think a shell is a shell, but sometimes the ones with
lots of striations and crinkly edges leave an interesting
mark.
Just try everything. Keep notes - you'll forget, if you
don't.
best
Dannon Rhudy
> Flashing slips:
>
> UPS brought me 50 pounds of Helmer yesterday. I drove it to school, and
> I stayed in the EMU studio until after midnight, mixing a dozen kinds of
> flashing slips. Some are EPK, some are helmer, some are shino slips.
> Some are partly calcined for use on bisque.
>
> First: Will the claybody under the slip effect the flashing/color?
>
> I know the "thick or thin" question is a crapshoot... the flat canteen
> forms I am making for tests have a clear front and back,
John Boyd on sat 16 feb 08
Dear Kelly,
Thanks for providing the chance to respond to two things
at once; less to your exact initial words and more to the few Clayart
attitudes that spawn them. First of all, I think it silly that in a field
as complex as ceramics one should ever feel required to apologize for asking
questions. If people have a problem with "newbies" asking "stupid"
questions then they should form their own separatist group. Questions are
what Clayart is for, and everyone, pottery rock star or not, has started out
a rank beginner. I think it high time people quit coming to the Clayart
table with their heads down and tails tucked between their legs; this isn't
the military. The idea that someone should feel skittish about utilizing an
educational resource because of other's responses makes me angry.
To try and answer your questions with my limited experience: From all
the tests I have done, the clay body will affect your fired slip color. I
have found, with my tests, that thin applications of slip over clays with
little trace mineral content have warmer palettes, while thin applications
of slip over darker clays with higher trace mineral content have a tendency
to move towards red-brown to dark orange. Reduction cooling reverses this
in a way, light colored engobes tend to look like dead fish skin and citrus
peelings, while darker clay engobes have a better array of colors. Engobes
with colorants are a whole other ball game and testing is what informs
best.
Thick can be pretty thick, like Matt Long thick, but most are designed
to be as thick as two coats of shino before they all seem to want to crackle
and flake off. The thinnest application of slip I have used with
effectiveness is about the consistency of skim milk. I prefer to use slips
that are a little thicker than half and half. Add to the above paragraph
the idea that by the time you dip these slips twice at a certain thickness,
the color on light and dark clay will be roughly the same. Thin
applications of slips on clay will not give you the true color of the slip
alone.
Yes, you can stack any wood kiln so tightly it will choke. I like to
make waves; stack the front top a little tight and let the bottom open up so
the flame is forced down and to the back to begin with. You can tumblestack
pots on shelves if the posts are tall enough. I often put bricks on shelves
to stilt pots up and cluster them up. Making a mess can be great.
Seashells are like any other aesthetic variable, some work well with
what you are doing, while others do not: It depends on form, surface,
intent...etc. For the inside of bowls, many prefer shells with a natural
curvature (like limpet or clam) to support the shape. Flat shells work well
with trays, and I have found a type of scallop that curves back on itself
that seems to love being stuck to "roundie" forms. How much pattern do you
want? How much do you want to clean off? How obvious do you want the shell
to be. Is it all about the shell? See what I mean...?
If you don't fire past cone 10 in front, I respectfully suggest you try
to make the firing stretch into 30+ hours and see what happens. I think
with added time, the results in the back will be more to your liking.
Ruggles and Rankin and many others make little bowlies of wadding, fill them
with salt and distribute them through the kiln. It's an interesting
technique for any kiln, and it really helps in kilns that fight gravity to
deposit ash and volatiles on the wares. In a train it might be great (I'll
have to try that too), but I would first deduct that amount from what I
usually put through the kiln in the firing and see how strongly it affects
the results I want. Although, occasionally, too much of a thing can be
wonderful.
Charcoal can be in a sagger, reusable bowl or cuddled up against a
pot. Testing will tell what's best for you. I like it up close and
personal; Most of the time there is charcoal coke left on the pots, but when
I get one that is black and smooth with no chunks, it is worth the risk.
It's like having a Guinness once in a while when the ale gets boring.
You don't necessarily need a sagger for hidasuki (fire cord)
markings. Try them at the back of the kiln, or bastion off your special
pots by surrounding them with bigger forms that will deflect the flames
onslaught. I think a major difference between great work and superb work
lies in what you are doing. Write down every theory you have, every idea
you come up with, test it to death, engage in dialogue and get those
answers. Jack Troy has a great book, but it isn't the only book...they
harder you look in obscure areas, the more rewarding the info you will
find. Here's a huge hint: The inhabitants of OZ have a woodfiring
conference history far longer and richer than ours...I wonder what they have
tried?
Best of Luck,
Cas
PS I'll send the pots after this week. My truck needed an overhaul in the
steering column, so I am working away from the studio and post office right
now.
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