figure 1: bottom side view of the finished pieces

The design of this experiment, then, was pretty straightforward. Since the jet black areas correspond to where the pieces touch the sawdust and manure, why not just raise the pieces up so they don’t touch them anymore? As you can see from the results, figure 1 above and figure 2 below, the experiment was, in a strictly technical sense, quite successful, as there was hardly any sign of those shiny jet black areas visible on these pieces.

figure 2: top side view of the finished pieces

Upon closer inspection, though, I began to feel rather disappointed. I had, perhaps unrealistically, hoped to retain some of these other colors besides the jet black, such as the deep maroon red, and especially the pretty blue or greenish grays, as seen here and here — which are completely missing in these pieces here.

I did notice that on my regular pieces, e.g. the ones shown in the links above, the most interesting colors often seem to happen in a transition zone that borders the jet black area, which I figured must have something to do with the reduction atmosphere resulting from having the densely packed sawdust or manure nearby, the smoldering of which, after all, was what has caused the carbonization of the jet black area in the first place.

figure 3: how the pieces were set up before the firing

And here it is, in all likelihood, the reason why we are not having those wonderful colors. As you can see in figure 3 above, I have kept the sawdust and manure layer in the pit unchanged, and simply raised the pieces up by setting them on a BBQ grill instead; but now, in hindsight, it’s obvious that the grating was set far too high above the sawdust and manure (figure 3, 4), so there was simply no chance for the pieces to be in a reduction atmosphere any time during the firing, as oxigen would have been plentiful in the air space beneath them.

The result (figure 1, 2) was quite predictable then — a set of pieces that were very lightly fumed and very blond on the bottom side. And this is really not what I had hoped for when I started the experiment. My intention was to get rid of just the jet black area, while keeping most, if not all, the other colors intact.

figure 4: view of pit at end of the firing

Okay, so I was disappointed. But as a thought experiment, let’s take off that mad scientist hat for a moment, and try instead to look at these pieces afresh, without any presupposition — then perhaps, just perhaps, we could come to the conclusion that, if solely based on looks, these pieces are really not so unlovably hideous, after all.

Furthermore, even if we were to insist on disregarding aesthetics, and sticking purely to techniques, there is still the interesting question of why we see a difference between the top and bottom sides of the pieces — and the more pragmatic question of what we would need to do, if the objective is to have the same blond effects on both sides. Perhaps we could put a grill or some kind of wire mesh on top of the pieces too, to keep the hot embers and ashes at a distance, like we did at the bottom?

And here is what I am really trying to say — even as I profess to favor a structured and methodical approach to my firings, with clearly defined goals and objectives, I still strive to keep an open mind for any accidental and unintended results, as they may open new venues and show new directions for me to proceed further. Such happy accidents are, I suspect, rather common for all creative endeavours, whether in art or in science; and we would do well to learn to accept and embrace them, even if they might have come originally as spoilers for our plans and intentions.

Now, four years later, I have managed to file quite a few posts with enough pragmatic details for others to use as reference, or even as a starter framework for their own pit firing experiments.

One thing has not changed much, though. My firing approach remains very specific to a rather personal obsession, a mad scientist-like urge to understand how different fuming effects can be arrived at with any given fuming material or firing process.

figure 1: books on pit/smoke firing

To that end, my emphasis is on achieving a broad range of surface colors and effects; and it’s no coincidence that the primary form I’ve chosen for these experiment is a simple, anonymous, and unassuming river rock form — which essentially serves as a neutral canvas to receive fuming marks, and which will not call attention to itself and distract the viewer’s focus from those fuming effects.

So this is why I’d cringe a little, sometimes, when approached by someone wanting to use my firing methods for their very expressive figurative sculptures, or for some other highly specific and well articulated forms. More often than not, I would end up telling them, well, yes I’d love to help you, but you really ought to look into these other ways, too.

Unfortunately, as I tried to scrounge the Web for free information on these more specialized firing approaches, I came up nearly empty handed. What we do have are tips and how-to’s for the more typical firing, some of which are listed in the Resources Page of this blog.

This does not mean, however, that there are no good information available out there — it’s just that they are not on the Web, but instead are buried in a handful of excellent books (figure 1) on pit/smoke firing, which you can find listed in my Resources Page as well.

One of these days I’ll have to write a proper review for the books listed there, instead of just telling you to buy them all, as I did. :-) But since this is a post about other specific ways to pit/smoke fire, for now I will simply focus on a few artists whose work I like, and whose firing approaches are quite different from what I’m currently doing, to give you a taste of what else is available out there.

I’ll start with figurative sculptures. One artist that I like a lot is Susan Halls; some of whose work can be seen here and here. While there is hardly any description of her working methods online, they are actually very well documented, even with good illustrations, in the following books: Sawdust Firing by Karin Hessenberg, and Smoke Firng: Contemporary Artists and Approaches by Jane Perryman.

And for those of you working with abstract and elegant forms, Gabriele Koch is someone whose work you really cannot afford to miss. She does not appear to have a website, but you can see some images of her work here, here, and here. There is a brief description online of her working methods; additionally, an article by Tony Birks for an exhibition catalog describes her aesthetics and methodologies in more details. However, the best information on Gabriele Koch is to be found in books as well: Sawdust Firing by Karin Hessenberg, Ceramics: Smoke-fired Pottery and Smoke Firng: Contemporary Artists and Approaches, both by Jane Perryman. All three books cited above contain a good section on Koch and her work. She also has a monograph out, though I have not been able to get hold of a copy yet.

Lastly, for those of you who would like to get a lot of colors onto your pots in a more direct and assertive way, Dan Ishler, a potter from Washington State, has an interesting way of working, which is also summarised here in the last paragraph of his c.v. online. More samples of his work can be seen in his gallery on the Whidbey Working Artists website (scroll to slide #22 and beyond to see the pit fired pieces.)

Okay, as I’m trying to finish this blog post, I noticed that all three of the approaches I suggested above are ones that I’ve wanted to try out myself. In other words, this is still all about what I do or plan to do. Furthermore, I’m still only dealing with the firing of smallish pieces that can be carried out quickly, in a small pit in one’s own backyard, not generating too much visible fumes and smoke — since my pit firing practice is constrained by the urban/suburban environment in which I live.

But for those of you who are working in a different setting, e.g. in the country side, where making a bit of smoke is not a problem, or who have access to different equipment, e.g. a gas or wood kiln — or even a raku kiln — you actually have many other options that are quite different from both mine and the ones mentioned above. For example, the closely related methods of saggar firing are well worth your consideration. I myself have started my career in smoke firing from a saggar workshop with Maria Spies in 2002, have played with saggar firing on and off since then, and would probably do more if I had better access to a gas kiln or raku kiln.

So what I am saying is, well, don’t limit yourselves to just what I have on offer here. There are many, many other ways, and you really ought to check them all out, too. Really.

figure 1: oil on paper from my art student days

On the 3rd day of September, disaster struck. The hot water heater in the house attached to my studio building broke, while the tenants were away on a camping trip, and the studio became flooded with 3 to 4 inches of warm standing water. To make a long story short, I spent the rest of September salvaging what could be salvaged, and getting rid of what could not be or were not worth salvaging. In the process of doing so, I found myself getting reaquainted with some old, old artwork from my art student days, dating back to the early 80′s (figure 1, 2, and 3.)

figure 2: a brush and ink sketch of a beach scene

So a big part of my world was suddenly turned upside down. I had originally planned on using most of September, the last of the sunny months here in rainy Seattle, to finish a series of firing experiments; instead, I ended up spending the whole month drying old sketches and old notebooks, and sorting out what to keep and what to throw away.

It turned out, however, that this whole exercise has not been in vain, as having your whole world turned upside down on you can have its hidden benefits, too, once you get past the shock and distress over what you have lost. In my case — well, in this particular case anyway — what I’ve gained is a new perspective on the big picture. So, what is this ‘Art’ thing that I’m doing? Where have I been, and where am I heading? Where do I want to go, and how do I get there from here?

figure 3: a pencil drawing from the distant past

Now, for those of you who are long time readers of this blog, if you should begin to think that I am about to abandon my dogged experiments with pit firing to refocus myself on ‘art making’, or worse, to leave pottery all together and return to the refined and genteel world of drawing and painting — have no fear, as that’s not what I had in mind at all. :-)

What I did have in mind, though, is to become more conscious of the distinction between art and craft, and to step back, every now and then, from a total involvement with the immediate joy of making and doing, to try and place what I do in the context of something that might fit into the grander scheme of things.

figure 4: finally studio is ready and better than before!

Alright, enough of this cryptic sophistry — for now it’s nothing but words anyway, so let’s just leave it at that. But what is likely to happen here in a tangible way, in the coming months, is a total revamp of this website.

More specifically, the documentation for each firing, e.g. the planning notes, firing logs, and associated photos and video clips, will all be put online in their original unvarnished form, warts and all — but in an area separate from this rambling blog.

Meanwhile, a different section — again separate from this blog — will contain the latest version of my how-to notes, e.g. for packing fuming materials, or for the firing process itself. Currently they are scattered throughout various blog posts, some from over four years ago, and many contain possibly erroneous or at least obsolete information. Besides, having a separate section for the more carefully researched how-to instructions will allow me to write these blog posts here more freely and spontaneously, too.

Finally, from now on I will try to be more responsive (and more timely so) to the comments left here — and to update the blog with new posts more frequently as well. And, just as the studio itself has been salvaged from, and indeed made better by the flood (figure 4), hopefully this blog and website will likewise gain a new life from now on…

I most probably belong to this second group. Well, some might even say I had gone over the edge, that I was actually more a mad scientist than an artist — which I would gladly take as a true compliment, by the way. :-)

figure 1: just copper mesh, no steel wool, and no salt

And here is a manifestation of this truth over beauty tendency of mine. Instead of following my own proven three amigos (steel wool, copper mesh, salted raffia) formula to make more good-looking pieces like these or these, I decided to try just one amigo at a time, and see what will happen.

As a first experiment in this vein, I wrapped two of my terra sig-burnished rocks with Chore-Boy type copper mesh, no steel wool, and plain unsalted raffia; and did the same to two more pieces, but with steel wool and no copper mesh this time. The four were then fired together using my new copper carb-free firing protocol, i.e. in a bed of sawdust and horse manure, but without copper carbonate or any other chemicals.

The results are shown in figure 1 above for a copper mesh piece, and figure 2 below for one of the steel wool pieces.

figure 2: steel wool only — no copper, and no salt

In some way I wasn’t too surprised by the results, as I had already seen what appeared to be the fuming effects — though with the presence of salt — of copper mesh and of steel wool from past firings (see figure 3 and figure 4 below.)

Nevertheless, I was still quite taken aback, first and foremost, by how unmistakably clear and precise the imprints of the copper mesh and steel wool strands were on the surfaces of these rocks. Indeed, what is most striking about these pieces is the complete absence of larger swathes of colors — all the marks are linear, and only at exactly where the fuming source materials have been and nowhere else.

figure 3: copper mesh effect with salt present

Incidentally, what I had wanted to find out originally, is whether the salt near the copper mesh and steel wool — via the salted raffia — had a role in the fuming marks and colors in a more typical firing, i.e. one using all my three amigos as fuming materials. In other words, was the salt needed as some kind of catalyst, chemically speaking, to get the copper mesh and steel wool to fume so colorfully?

Or, more figuratively, did the salt act as some kind of ‘outside agitator’ or agent provocateur, and cause the copper or steel wool to ‘act up’? Or could the copper (or steel wool) actually have become volatile enough by itself, under the intense heat of the flames, to do its own ‘thing’ regardless whether the instigation and abetment by the salt were also in the mix? Well, I can see I’m veering close to some treacherous territories with my choice of words in the sentences above, so let’s get back on topic — art and science, and not politics, shall we?

figure 4: steel wool effect with salt present

Anyway, it looks like we have a mixed verdict here. The copper and steel wool did indeed act up on their own, but the presence of salt — in previous firings — also seemed to have helped spread the colors around quite a bit more. Perhaps a follow up experiment should go something like this: same copper mesh or steel wool as before, but cover half of the piece with salted raffia, and the other half with unsalted raffia — then if our hypothesis is correct, we should see color smears on one side, and clear linear marks on the other.

figure 1: three recent black-and-gray pieces

Well, it must have been in a corner where we forgot to sprinkle copper carbonate; and the copper mesh and salted raffia wrapped around the piece must have gotten knocked loose by falling logs too — so I thought to myself, and promptly forgot about the whole thing.

Then I started to do a lot of firings in my little backyard pit, and much to my chagrin, these all-black or black-and-gray rocks also began to crop up a lot more frequently (figure 1 above, and figure 2 below.)

figure 2: three recent black-and-gray pieces (other side)

I was puzzled. Luckily, I have been doing what I preached, and have plenty of notes and photographic records for all the firings I’ve done in this pit. So now it’s time to dig these notes and photographs out, and see if we can get a handle on what’s been causing the problem.

Below (figure 3) is what it looks like at the end of one particular firing where all six pieces have gotten plenty of colors. Notice how the outline of each piece is clearly visible, as they all have emerged from the ashes and are now completely exposed.

figure 3: all pieces here have nice colors

In contrast, the photo below in figure 4, also of the end of a firing, is from one where half of the pieces were black and gray, or nearly all black and gray. As it turns out, there were also six pieces in the pit, in a similar configuration as the above, but more evenly distributed.

But you wouldn’t know it from just a quick look at the picture below (figure 4), except for the three pieces clearly shown on the right hand side. And you probably wouldn’t have guessed there was a piece in the center had I not told you so.

figure 4: only the three exposed pots have good colors

Since it so happens that I have taken a group shot of the pieces immediately after their removal from the pit, arranged as per the original layout during the firing (figure 5, below), let’s compare these two photographs side by side and see if we can learn anything from them.

What we can clearly see, then, is that the three exposed pieces in the previous picture (figure 4, above) turned out to be the three colorful pieces in this one, while the others turned out to be just black and gray, or mostly black and gray with just a small area of colorful fuming.

figure 5: all six pieces after removal from the pit

So a pattern is emerging: if the hot embers have burned down enough to expose the pots at the end of a firing, then chances are that we would get decent colors. On the other hand, if by the end of the firing, a pot is still buried in the ashes, then we may get a black-and-gray piece instead.

figure 6: center and lower-left pieces are black and gray too

Well, that was a pretty good hypothesis as far as hypotheses go, but in real life things always have a way to turn out more complicated than we think at first. Let’s consider the photograph above (figure 6), which shows the end of yet another firing.

In this firing there were five pieces in the pit, and indeed, the one buried in ashes in lower right turned out to be all black and gray. No surprises there. But how about the other four? Let’s examine them one by one, starting with the one in the lower left first.

figure 7: unburned saggar-shell of lower left piece

As you can see in the close-up photo above (figure 7), the piece has fully emerged from the surrounding ashes. However, the fuming materials wrapped around it, in particular the salted raffia, is still pretty much intact, and doesn’t even show much charring either, except maybe just a little in the lower right hand side.

Okay, I did write about aiming to have the saggar-shell of fuming materials still visible at the end of a firing; but I was talking about having a flimsy remnant of it barely hanging onto the piece, and that’s not what we are seeing here.

figure 8: what’s under the unburned sagger-shell

Instead, what we have here is a largely unburned bundle of packing materials, the removal of which reveals a nearly unmarked surface underneath (figure 8, above) — barely fumed to a very light gray, with just a slight hint of colors only at the lower right corner, roughly corresponding to where some charring was detectable in the previous picture (figure 7).

So it sure looks like we are onto something here. Still, caution dictates not drawing any conclusion just yet — as we still have three more pieces to examine.

figure 9: unburned saggar-shell of center piece

Let’s now move on to the third piece (figure 9, above), the one that was at the center of the pit. Again, this piece has emerged completely from the ashes; and it, too, has a coat of mostly undisturbed and unburned raffia wrapped round it.

And the result? Well, there are no surprises here either — we have a barely touched grayish surface beneath the coat of unburned raffia (figure 10, below), just like we do on that previous piece.

figure 10: what’s under this other unburned saggar-shell

Now, for something completely different, let’s take a look instead at the piece (figure 11, below) that was in the upper right hand corner in the pit. Immediately we can see that not only does the coat of fuming materials, or whatever is left of it, look precariously flimsy; but part of the bare surface of the piece itself, fumed to a dark orange brown color, is showing through as well.

figure 11: flimsy saggar-shell remnant on upper right piece

And indeed, the removal of this flimsy shell reveals a surface (figure 12, below) that’s well smoked into a deep orange brown; furthermore, even without wiping off the soot and dirt still on it, one can already see interesting fuming marks starting to appear in places.

So we can almost draw our conclusions now: if the embers have burned down to expose a piece at the end of a firing, and if the fuming materials wrapped around the piece have been burned down to a flimsy shell, then we’ll probably see some nice colors; otherwise, we may see a black-and-gray pot instead.

figure 12: good colors under flimsy saggar-shell remnant

But let’s wait just a little longer, and take a look at something that’s perhaps even more convincing — the last piece to be examined (figure 13, below), which was in the upper left corner of the pit during the firing.

What’s interesting about this one is that it has a saggar-shell that’s partially burned, i.e. the upper right 1/4 or so has burned down to a thin flimsy coat like the previous one (figure 11), while the remaining 3/4 consists of unburned raffia like what was on the two gray pieces shown earlier.

figure 13: partially burned saggar-shell on upper left piece

After removing this partially burned shell we come upon something most interesting but not unexpected by now (figure 14, below), i.e. what was under the flimsy 1/4 of the saggar-shell remnant got fumed with good colors, while the remaining 3/4 that was under the unburned raffia turned out to be largely grayish in contrast.

In other words, on this piece one can clearly see how the varying conditions of the remaining saggar-shell at the end of a firing affect the coloring underneath.

figure 14: colors under flimsy part of saggar remnant only

Well, in truth I have just misspoken somewhat. The final condition of the shell actually does not affect the fumed colors per se; rather, it acts as a post mortem indicator of how well that fuming has succeeded. What does affect the fuming, as well as the final condition of the shell, is the flame patterns surrounding the piece during the firing.

So this is what it’s really about: good flame action around the piece insures that the fuming materials — the metals and the salts — will get sufficiently heated to become volatile and do their chemical magic, and the state of the raffia shell provides a visual clue to whether enough flame action is taking place, or has taken place, for this chemical magic to occur.

With this focus on flame action in mind, we have now yet another tool at our disposal during a firing, as these saggar-shells around the pots can provide tell-tale signs of how and whether the fuming is working. I’ll have more to say about the practical use of this tool — as applied to a recent firing — in a future post.

I came really close to showing that I can get the same effects with copper netting from “Chore Boy” type copper scrubbers; but a real proof would require not having any copper carbonate in the pit at all — which I couldn’t really do in a group firing, where other people were there to get nice results for their pots, and not to help me prove or disprove some fine point in pit firing theories.

figure 1: these are fumed with copper-coated scrubber

But now I have my own test pit, and the only pots at risk are my own. Woo-hoo! So after two successful firings using my standard method, proving that this test pit works just as well as any other I’ve used before, I went for a test firing with no copper carb at all in the pit, and was very pleasantly surprised to see some very respectable looking results (figure 1) for my efforts.

figure 2: fumed with copper-coated scrubber (other side)

Here again, in figure 2 above, is another view of these three pieces, showing the bottom side that was embedded in the sawdust during the firing.

Well, the pieces surely look decent enough, and I have no complaint about them aesthetically; but after a while I noticed something. There actually wasn’t much — if at all — of the maroon reds and blueish grays that I was hoping for on these pieces.

What we have here is more an orange brown instead of maroon red, plus a cast of yellowish tint to the blue-gray areas, making them look somewhat greenish. For comparison, see these three pieces (figure 3) from a previous firing with plenty of copper carbonate in the pit.

figure 3: these are fumed with copper carbonate

Again, in figure 4 below, is another view of these three earlier, copper carb-fumed pieces. Here, too, you can see they have colors noticeably different from those of our “Chore-Boy” only pieces (figure 1 and figure 2).

So I was mystified. Take a look at these two pictures at the top of this earlier post, where I almost proved I got those copper red from Chore Boy mesh only: now that red clearly came from the Chore Boy netting, no? You can even see the unmistakable footprint of the copper mesh in the second picture there. In red, no less! Would I be asking too much to have just a little of that red here?

figure 4: fumed with copper carbonate (other side)

I remained puzzled until I went shopping one day for the next batch of copper scrubbers, and noticed, upon my return to the studio, what was printed on the packaging. “Copper coated”, it says.

Hmm… so what’s really inside these things there that got coated with the copper? It so happened that I had a small magnet nearby, so I placed it near one of the scrubbers, and voilà, mystery solved — this is basically a steel scrubber!

Now everything started to make sense. The thin coat of copper was burned off early on, leaving few traces on the pots. The remaining steel mesh then gave out fuming effects similar to what steelwool would do — yellow tints and orange browns.

figure 5: these are fumed with 100%-copper scrubber

The next logical step, then, was to go hunt down some scrubber made with 100% pure copper, and do another test firing. The result of that firing is shown in figure 5 (above) and figure 6 (below.)

Note that in this firing I didn’t use any steelwool at all, and there wasn’t any copper carb in the pit either. Just the 100% copper mesh and salted raffia packed around the pieces, plus my standard sawdust and horse manure in the pit.

So now I’ve got my copper red back. And the blue gray zone — now that’s some of the prettiest blues I have ever seen on pit fired pieces.

There are also a couple other things worthy of note here: firstly, I’m sure you’ve noticed different kinds of black, e.g. shiny and metalic vs. rich and deep, in the jet black areas of these pieces (see figure 5 above).

figure 6: fumed with 100%-copper scrubber (other side)

This actually is not something new or unique to this firing, but in the past this variation in the jet black area became obscured by the waxing of the pieces afterwards, which deepens the tonal values of the shiny metalic area and makes it less distinct. Here the black areas have been left unwaxed instead, so the full tonal range is preserved.

Secondly, the terra sig flaking and peeling problem is still with us (figure 6, piece in upper right.) To be sure, I have changed my way of working, i.e. to not burnish the pots before the terra sig application, and as a result the lossage rate has been greatly reduced in all firings since then. Still, as you can see here, the problem is not totally gone; and I’ll have to go back and confront this issue again one of these days.

Unfortunately these BBQs didn’t work out all that well, as they were not designed for the prolonged high heat generated by a log burning fire. My BBQ smoker, for example, has paint on it that would start to burn after a while, and would give out noxious fumes and visible black smoke. Talking about trying not to draw attention! So I gave up this approach after just a few times.

figure 1: the cast iron ‘fire pit’ in action

Then I started to see these stand-alone outdoor ‘fire pits’ made of metal or clay at the patio furnishings section of department stores. Would these work for my purposes? After all, they were designed to burn logs, no? So I bought a cast-iron one (figure 1) from Home Depot and start to experiment with it. I did my first firing with it at the end of April this year.

Initially, I worried a little that, since the bottom of this ‘pit’ thing doesn’t touch the ground, the firing may cool too fast, resulting in incomplete color development, or worse, in cracking and breakage. Well, it so happens that my fears were unfounded. The pieces turned out just fine — see figure 2 beblow: a group shot from the second firing, just after the pieces were removed from the pit, before any cleaning or waxing. Oh the first firing was good too, but I didn’t have a group shot like this to show you. :-(

figure 2: result from second firing

So now I have a little test pit to try out different fuming methods and effects, and to ask questions that I’ve been itching to have answers for, e.g. can I get away with not using any copper carbonate at all? How about using no copper of any kind, not even the copper nettings (e.g. from a “Choreboy” type copper scrubber), just steelwool and salted grasses? Or no copper, no steelwool, and just the salted stuff? Or how about using copper and steelwool, but no salt at all? Or…

Do you want to know the answers, too? Stay tuned. As it turned out, I have done many of the experiments already — I have done 10 firings in this test pit so far — and will show you some of the results shortly in an upcoming post.

Meanwhile, here is another picture of a nice piece from this firing ( figure 3 below) after it has been cleaned and waxed.

figure 3: piece HC0812-23 from the second firing

And below is the other side of the same piece (figure 4). Notice the inscription on the piece — which says “HC0812-23″. Okay, here is what this is all about. “HC” is my initials, “08″ is for the year 2008, and “12″ for the month of December, and “23″ means this is the 23rd piece made in the month of December 2008.

Someone once asked me whether this is an On Kawara kind of thing. Well, no, actually it isn’t. Not at a conscious level anyway.

For me this is simply a unique identifier — a serial number, if you will — for the piece, that comes in handy in conjunction with meticulous note taking, which I usually do. Here, for example, I can look up my studio notebook and see that this “HC0812-23″ piece was made with OH6, a white porcelaneous stoneware clay from The Clay Art Center, that it has two coats of OM4-based terra sig, and that it has been bisque fired to cone 012.

figure 4: piece HC0812-23, other side

Also, from my firing notebook, I can see that this piece was packed with my standard three amigos of steelwool, copper netting (“Choreboy”), and salted raffia, and that it was placed in the first layer (directly nestled in sawdust) at the north end of the pit.

In the photo below (figure 5) is another piece from the same firing. Again, from its unique identifier, HC0812-35, I can find out that it, too, has two coats of OM4-based terra sig, that it was bisqued to cone 012, that it was placed in the first layer in the pit (at the south end), and that it was packed with the same three amigos of steelwool, copper netting, and salted raffia. The claybody, though, is a commercial buff-color stoneware called Idaho Buff, also from The Clay Art Center — and not the porcelaneous, B-Mix type OH6 used in the previous piece.

figure 5: piece HC0812-35

Below is yet another view (figure 6) of the same piece.

“Aha!” — I can almost hear some of you exclaim now — “I see these nice maroon red areas in the OH6 piece, but none here. So white porcelaneous clay gives you these reds, and the buff clay doesn’t, yes?”

Well, no, not so fast please, my friend.

Remember, we have precise documentation on clay body, surface treatment, bisque temperature, etc. because these information can be easily recorded and documented. In a typical pit firing, however, there are a lot of other information, some of which are far more critical than what we have here, that are nearly impossible to record with any degree of certainty and specificity.

figure 6: piece HC0812-35, other side

A prime example is the flame pattern. How much flame action did each piece get to see? For how long each time, and at what stage of the firing did this happen?

Another is the firing atmosphere local to the piece in question. How early did the piece become exposed, and thus had its fuming materials burn in an oxidizing atmosphere? Did it then get buried by embers and ashes again, and thus entered a reduction phase locally? And when did this happen? And did the ashes burn down eventually and re-expose the piece again before everything cooled down?

While impossible to document precisely, such information can be gleaned in a general way, via written notes in conjunction with photos and videos taken during the firing; and they provide important clues to interpret the results of the firing. I’ll have more to say about this in a future post.

(Update 2009-10-25: now I typically bisque my pieces to cone 012 instead.)

figure 1: a recent pit fired piece

What I want to write about in this post, though, is how I use fuming materials to achieve the kind of results as shown in photos above (figure 1) and below (figure 2). This approach, of course, does not work aesthetically in all situations — so I am offering this only as a hopefully useful reference. As always, take whatever you need from it and adjust to your own requirements as you see fit.

figure 2: back side of the piece

But first take note and see how different the piece looks from the more common pit fire results (figure 3). In particular, there is no bare area on this piece — every square inch of it is covered with fuming marks, and the colors are rich and deeply saturated as well.

So what’s the secret? Besides the use of terra sigillata and a low bisque temperature at cone 010, the real key to the colors is what I use as fuming materials, and how I pack them around the piece before the firing.

figure 3: more typical pit fire results

Without further ado let’s jump into the description of my three amigos, the three key ingredients that I’ve packed around just about every piece I’ve made for those recent firings. First is steel wool (figure 4), which I usually pack as the first layer directly on the piece. Note masking tape is used to secure the steel wool strands, and to keep them as close to the surface of the piece as possible.

As I’ve written in a previous post, it’s critically important that you separate the steel wool into fine strands before attaching them to your pot, or else you’ll likely get a big flat unsightly brown spot instead of nice flashes of beautiful colors!

figure 4: amigo #1 — steel wool

In general, I’ve found it helpful to think about breathing — i.e. allowing your pot to breathe even as you pack layers and layers of fuming materials around it, so that flames and turbulence can reach in, stir things up, interact with the fuming chemicals, and deposit all kinds of colors onto the surfaces of your piece.

The second of my three key ingredients for fuming is copper nettings (cut from a common household copper scrubber, e.g. ‘Chore Boy’.) Note that in the photo (figure 5) below I have the ‘Chore Boy’ and steel wool covering different parts of the piece, because I was performing an experiment to see which material causes which kinds of effects. More typically I use both in the same area and applying them on top of each other, instead of keeping them separate as shown here.

(Update 2010-12-14: these days I frequently — but not always — place copper mesh in the first, and steel wool in the second layer instead, which seems to produce more interesting results than the other way round, usually. )

figure 5: amigo #2 — ‘Chore Boy’

Again, I hold the copper nettings close to the surfaces of the piece, using masking tape as well as twine in this case. I often use only masking tape, however, and suffer no ill effects from doing so.

The last one of my three amigos is salted raffia (figure 6) or salted burlap. Take note of the word ‘salted’!! This is basically a kind of artificial seaweed, and the key chemical is the sodium chloride in the salt. This is not just grass — it’s salted grass. And, once again, it’s wrapped tightly over the other layers and the piece itself with the help of masking tape.

figure 6: amigo #3 — salted raffia

Note how much raffia I’ve used. It’s all around the piece in a thick layer, covering its surfaces completely. Note also that, while this raffia layer looks formidable, it’s not air tight at all. Remember we talked about breathing a while back? So now we have a breathable saggar of sort — yeah, this is the key idea, which we’ll come back to later in this post.

Now that I have my three layers of iron, copper, and salt (the three amigos viewed chemically), I simply wrap a final single layer of newspaper (figure 7) around the whole thing and call it good.

Note: if you wrap more than two or three sheets around a piece, then the flames may not burn out the paper completely in some firing situations (hint: think breathing again), resulting in a darker and smokier piece with muted colors — which could be what you’d actually prefer, of course.

figure 7: final layer of paper with the word ‘top’

This is not a critical step, though, and I don’t always wrap my pieces with this final layer of paper; but one advantage for doing so is you can write on the paper to mark how the piece should be stacked in the pit. In this case I had written the word ‘top’ to indicate which side of the piece I want facing up in the pit, so that the opposite side will be buried in sawdust and hopefully turn jet black as a result.

Now, about the pit itself: people sometimes ask me how much copper carbonate I put into the pit. Since it’s hard to describe in words, here is a photo (figure 8) of the typical amount and method of application.

In other words, the copper carb is sprinkled onto the sawdust (and/or dry horse manure) layer, in an amount that makes the pit look greenish while still allowing the underlying color of sawdust, etc. to show through.

These days I don’t usually put any other chemicals besides copper carbonate in the pit, even though I have experimented with baking soda, epsom salt, etc. in the past.

figure 8: sprinkling copper carb into the pit

Oh, a note on safety: always wash your hands after handling that nasty green stuff! Better still, wear latex gloves whenever you work with copper carb or similarly toxic chemicals.

(Update 2009-10-25: check this new post and see that you don’t really need to use copper carbonate to get the nice copper fuming results.)

Now, before we go on further, you should take note that this method for packing fuming materials is closedly tied to the specific firing method I use. As I mentioned earlier, I fire in a relatively shallow pit with a raging fire for 2 hours, followed by 3 hours of fairly rapid cool-down period. The whole firing should last no more than 6 hours including prep and clean-up.

Shown below (figure 9) is how the pieces are stacked in the pit. The pit layout is like this: a 2-3 inch layer of sawdust and/or horse manure at the bottom, followed by one or at most two layers of pots, then a layer of kindling, and finally the main fuel — typically firewood of medium sizes. The fire is stoked as needed for 2 hours with addition of firewood usually about two to three times the initial amount.

figure 9: embedding pieces in the sawdust

And here is the most important aspect of this layout: there is no sawdust around and above the pieces, and the pieces are exposed directly to flames and turbulence — except when partially blocked by protective shards so placed or by other pots — during the initial 2-hour raging fire period. In other words, this is not a slow burn down process as is common in a more typical deep pit or barrel firing.

In a sense this style of firing is more akin to an open bonfire, and with this in mind I now return to the notion of breatheable saggar mentioned earlier. Let’s take a look at the photo (figure 10) below of a pit at the end of a firing.

figure 10: saggar-shell stays intact at end of firing

See how the hot embers have burned down to the bottom of the pit, completely exposing all the pots? However, unlike the naked cylindrical forms next to it, the roundish piece is completely covered by a fuzzy coat of something or other.

This fuzzy coat or shell, barely clinging to the surface of the piece — now this is what to strive for when using this packing method, i.e. to have this breathable saggar — or whatever is left of it — still remaining (but barely so) at the end of the firing.

Below (figure 11) is a closer look at a similar piece from a different firing, where this flimsy saggar shell remnant had just been peeled off after the piece’s removal from the pit.

figure 11: peeling the saggar-shell off the piece

A closer look at this shell reveals that the copper nettings (i.e. ‘Chore Boy’) provided the underlying structure to hold the shell together, while the steel wool strands, some unburned raffia, and some ashes helped flesh out the now fabric-like shell.

So herein lies the key to having success with this fuming method: if you have a shell like this to peel off when you take your pot out of the pit, you’ll have a very good chance of seeing some nice fuming marks and colors once you get this shell off.

Well, at least this has been my experience so far. I hope you’ll have the same results as well; and if you have any success with this method — hey, drop me a note. I’d love to hear some success stories! And don’t forget to experiment and to adjust this method according to your own firing situations. Good luck!!

Appendix: How To Make Salted Raffia/Burlap

I’ve learned this from Maria Spies. In the U.S., raffia (and burlap) can be bought from craft stores like Michael’s. Canning salt is available in many grocery stores. Regular table salt should work fine, too.

figure 12: raffia (and burlap) soaking in brine

Here is the procedure: gradually add 4 lbs of canning salt into 2.5 gallons of hot water, stirring as you go. Stir some more after all the salt has been added. After the salt has been fully dissolved, add in the raffia and/or burlap (figure 12). By the way, you may want to wear rubber gloves while doing so; this is a very saturated solution of salt and is somewhat caustic.

figure 13: salted raffia drying in the sun

Leave the raffia and/or burlap soaked in this brine for 2-3 days, then take them out to dry in the sun (figure 13). Take care to not spread them on top of vegetation (e.g. your lawn) as the salt tends to kill whatever is underneath. Once dried place them in sealed plastic bags, away from any steel tools, cabinets, and other implements that are not rust-proof.

(Update 2010-03-30: I don’t live here anymore, though I still keep a studio in the back as well as the kiln room pictured below. Apologies to all those of you who had seen this site before coming to my new home, expecting to find a working studio there. Nah… I’ve become a normal person — no more clay and dirt and mess where I live. :-))

figure 1: sculpture studio is my former living room

In the back behind the house, I have set up my pottery studio in an old storage shed (figure 2). There is a brand new electric kiln (an automatic Skutt!), a used electric wheel that I picked up for a good price, and a little portable kick wheel. By the way the large BBQ grill in the back is also a pottery tool — I will be using it for doing some pit firing experiments.

figure 2: the kiln room and pottery studio

As you can see, this kiln room and pottery studio is a chaotic mess. There are way too many things crammed into such a tiny space for it to be not messy. But I am reluctant to get rid of some stuff — like these skeletal looking parts for some figurative sculptures I used to make some 10-15 years ago (figure 3). I guess in the back of my mind, this is a series that has not fully run its course yet. One of these days I’ll get back to it, most probably…

figure 3: some skeletons from my past

mutant teapot rat #1

And here is the other one.

mutant teapot rat #2 (rat #1′s brother)

And yes, these pictures were from last year, 2006! Well, I’ll start posting more soon and bring the blog up to date. Glad to be back, finally!