search  current discussion  categories  kilns & firing - misc 

fast firing

updated thu 29 sep 11


kurt l wild on fri 9 oct 98

I wonder how many potters have done as Marc Ward did - fast fire. Years
ago, at Pigeon Lake in Wisconsin at some of my workshops we built a
variety of odd hybrid fast fire kilns in 55 gallon drums, etc. We
delighted in seeing how fast we could fire. Our record, as I remember
was abiout the same as Marc'sm 40 minutes to cone 9. Prior to that, in
the early 60's I built a one cubic foot kiln out of a Swedish product
(Durox, a cellular gased concrete) which fired to cone 10 in abolut 25
minutes. The speed was the thrill - but the bad part was that the pots
cooled too fast and cracked.

Kurt Wild
1000 E. Cascade
River falls, WI 54022 Phone: (715) 425-5715

web site:

Craig Martell on tue 22 dec 98


The "Slow and Steady" stuff made me think of what this guy from West
Virginia said sometime back in Ceramics Monthly. I think his name is Ren
Parziale. Does that sound right? Anyway, he said that he thought it was
odd that people would spend a lot of time making, decorating, glazing loads
of pots and then try and fire them on their lunch break. What 's the damn
rush anyway are some of you late for a bus or something?

Craig Martell in Oregon (It's pretty cold here so bring a hat and coat!)

Ben Shelton on wed 20 jan 99

Does anyone have any info about firing very fast? I have a friend who is
interested in the commercial end of the ceramics business who has heard =
firings going to 2100F in as little as one hour and ten minutes.

Has anyone out there ever run across any info like this?? Thanks, Ben

Ric Swenson on thu 21 jan 99

Ben Shelton wrote:
> ----------------------------Original message----------------------------
> Does anyone have any info about firing very fast? I have a friend who is
> interested in the commercial end of the ceramics business who has heard about
> firings going to 2100F in as little as one hour and ten minutes.
> Has anyone out there ever run across any info like this?? Thanks, Ben

It is fairly common for TILE MAKERS to fire tile very quickly. Contact
a tile maker....look in American Ceramic Society roster for tile makers
and / or for names and addresses of kiln manufacturers that specialize
in tile firing equipment...roller kil'ns, tunnel kilns,etc.

as far as firing POTTERY in short time..

Hey......push the envelope...what will sort of fast fire abuse will
"your" claybody take? Testing and experimentation will tell you how far
you can go.

Bisque firing or glaze? green/glazed ware? Watch for water smoking
period ( ie. very DRY wares.)

Watch for alpha/beta quartz inversion as clay and glaze go through
heating and cooling cycles.... ( when most 'dunting' seems to happen.)

BTW....? is the one hour and 10 minutes a "cold to cold" measure?

Interesting thread...


Ric Swenson

Alex Wilson on thu 21 jan 99

I just spent a few years in the industrial end of the floor tile business. We
used gas-fired roller hearth kilns, reaching 1120C and then down to about 200C
at exit in around forty minutes. And cycles get shorter every year!
Amazing things are possible, with the right body and glaze formulations and,
of course, the right equipment. Remember that tile is flattish.
If you want some technical info, contact Sacmi USA in Des-Moines, Iowa or
Dressler - whose address I can't remember, but you should be able to find them
on the Web.
These chaps probably won't want to be too helpful unless you have $80,000
burning a hole in your back pocket.
Good luck,

Ray Carlton on fri 22 jan 99

a bit of work was done here in australia with superfast firings in the late
70's when kiln makers were showing off their new fibre kilns...from what i
remember the results were pretty ordinary from this kind of firing

At 16:33 20/01/99 EST, you wrote:
>----------------------------Original message----------------------------
>Does anyone have any info about firing very fast? I have a friend who is
>interested in the commercial end of the ceramics business who has heard about
>firings going to 2100F in as little as one hour and ten minutes.
>Has anyone out there ever run across any info like this?? Thanks, Ben
cheers Ray Carlton

McMahons Creek Victoria Australia

Babs Ellinwood on fri 22 jan 99

Hope he has a good backer with stock in a kiln company, that's one of
the worse things you can do to a kiln, let alone the pieces in it. Talk
about stress !!!

Babs in Hernando, Florida ...slow and steady firing with out a mishap

Euclid's Kilns & Elements on sun 24 jan 99

>>>Does anyone have any info about firing very fast?>>>
>>>Has anyone out there ever run across any info like this?? Thanks, Ben>>>

Hi Ben,
This is a case where a "double wall" or "extra insulated" kiln is of no
benefit. Cooling fast usually goes hand in hand with firing fast. It`s fine
to fire in one hour & ten minutes but if it takes 18 hours
or more to cool, how much farther ahead are you?
I have advised people in the past to fire as fast as they can without
affecting their ware. This is pretty vague, as pretty much any change in
the firing procedure can affect the ware....however, most people understand
my point. The thinking is that over the life of the kiln, if you save one
hour of heating per firing, it adds up to quite alot of energy savings
which translates into $$ savings.
I should also point out that some clay bodies & glazes do not work well at
all when fired rapidly.
Slow & steady is the only way to go with some. A good series of tests will
help determine what you can get away with.
For what it`s worth,
Chris @
Euclid's Kilns and Elements
Web Site:

Valerie Mann on tue 11 may 99

I used to fast fire all the time but have stopped since many of the
new glazes don't respond as well to fast firing....the colours come
out better if done slower.
Bright Blessings, Val Mann
London ON Canada
ICQ # 1592406

mel jacobson on tue 30 nov 99

i am sure that nils is correct, but saying that, i have to admit
that i preheat most of my kilns, both at home and at the farm.
it is a habit.

i have a small, 60,000 btu burner that is more like an additional pilot
than a burner. i load usually early evening, turn that burner on
and let it burn all night. when i lite my kiln in the morning i turn the
burners to half power and leave it that way for most of the firing.

i have been trying to fire faster in the early stages, but seem not to
make the change very fast.

nils gets after me, but old habits are hard to break, and we are
all steeped in tradition and superstition. not good science.

so, i will promise to try and fire faster and save fuel, and not pass on
information that is incorrect.

i know,` doctor cure thyself`.....just wanted to admit that.
the 12 step process of becoming the `complete potter`.
stands away,
waiting to
smack us
from minnetonka, minnesota, u.s.a.

Fraser Forsythe on mon 6 dec 99


Just wanted to add some things I've learned about fast firing in the last few
of years. About 3 years ago I built a fibre kiln to fire Raku. I used a box (50
sq. ft.) of 8 pound density fiber, fastened to a metal grid frame with special
porcelain 'cone anchors'. I bought a venturi torch (185000btu) for about 100
bucks and -like all good Raku people- blasted away! Shortly after putting this
kiln together I decided to try firing a cone 6 glaze. I used (1) test piece. In
just under two hours the cone 6 started to drop and I shut the kiln down. Sure
enough the glaze had melted - ugliest green I've ever seen.

Since that time I've built two more models and upgraded to a 300000btu venturi
torch. I plan on updating my web page on RFK soon - sorry I've been so busy.
I've learned how to control reduction, how to avoid shelf cracking and now have
a collection of glazes that I'm very pleased with. I have to say, though, this
has not been easy! Many many many times I've opened the door and wanted to
shoot myself. Maybe this is normal even when you start firing a 'normal' kiln -
I don't know. I've passed on the plans to people willing to pay the shipping
and printing costs but with some reservation. A Bailey - it ain't! My
experimentation is with cone 7/8 and I'm now trying to get that down to cone
6/7. Many people want to use this design for cone 10/11. So far I haven't heard
of much success, though I have fired to this temp on a couple of occasions.

Last summer I gave a course on building and firing this kiln at the White
Mountain Academy in Elliot Lake. On the first day we put the kiln together from
scratch and fired a bunch of pots to cone 7 - all by dinner. The kiln works but
there is a definite learning curve. (for info on the course this summer :

Here are some of the lessons I've learned:

Most pieces won't fire twice at this speed.
Stoneware with iron content about 20% could develop bloating spots. Porcelain
is (obviously) fine.
Never never never never fire anything with silicon carbide in it if you want to
develop other glazes in reduction.
The size of this kiln is approx. 7 cubic feet and the best port size I've found
is approx. 15 sq. inches
The golden rule for fast firing is mass mass mass. Use narrow shelf supports,
and 3/4 inch shelves.
To avoid cracking make sure the shelving has as few contacts with supports as
possible...and this might be a no-brainer for most of you but I learned the
hard way:::: even if the shelf is just warm don't put one end on a surface that
is a good heat conductor. I've seen shelves crack that way when they were cool
enough to handle. Sitting them on wood will save your shelves every time.

I hope everyone understands that this is all about experimentation. I was
determined to make this kiln work because it fits my needs perfectly. I'm not a
production potter but I like to experiment and (slowly) get better at throwing.
Glazing is for me one half of the equation and I want to be able to experiment
with the added dimension of reduction. BUT I live in a residential area and I
dot want to spend thousands of dollars. And last but certainly not least I'd
rather not have to throw for 3 months just to fill up the kiln.

I had specific goals in mind for this kiln; I don't think it easily translates
to production or large scale.

Fraser Forsythe
ps. I've recently acquired a digital camera and hope to get some sample of
these glazes onto my site soon.

Mimi Patrick on sun 18 oct 09

Mel - wondering if you are doing a body reduction with your firing =3D
schedule? If so, how long and at what temp?

Mimi Patrick
Argenta Earth & Fire Co.

Michael McDowell on wed 28 sep 11


I have followed the flow of this discussion, and was relieved to hear
several potters whose work and thinking I respect taking exception to your
remarks on fast firing. I appreciate that your advice may be appropriate to
some situations, but it would be catastrophic for me to fire a load of pots
that fast. The glazes I am currently using all incorporate a large
percentage of volcanic ash from Mt. St. Helens. It seems that the tendency
of glaze to boil and froth as it melts is very much accentuated in these
glazes. I have settled on a fourteen hour firing schedule after faster
firing left me scraping my shelves from all the glaze that was leaping off
the pots.

Before I built my current kiln, I fired for many years in one of the small
updrafts as are manufactured by Olympic. I was getting up to cone 11 in 7 o=
8 hours but had to use a different glaze at each layer of the kiln to
account for the temperature variation. In that situation, slower firing
erased the temperature variation.

I think David Hendley's remarks with respect to letting the results of the
fire determine the best firing schedule are right on. We all work with
different clays, glazes, kilns, and we are all looking at achieving our own
"look" in what comes out of the fire. If we are to let "efficiency" rule ou=
creative process we will be throwing the baby out with the bathwater.
Especially the kind of penny wise and pound foolish "efficiency" that
blindly following your suggestion to fire fast might lead to.

I will certainly support your efforts to pursue faster and less fuel
consuming firings in your own work if that is the direction you chose to
take. I just don't think that it is appropriate to present that approach as
more than a possibility one might consider. I've considered it, and left it

Michael McDowell
Whatcom County, WA, USA