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Things I've learned: Glaze edition

I've been poking around the archives, trying to find the posts on glaze and overglaze recipes, because every now and then someone asks for them. I've finally found both, and have retagged them glaze recipes, so they'll be easier to find.

But recipes aren't the only important information. There are details of mixing and application that need to be considered.
 
Consistency. Glaze recipes tend toward dairy metaphors. A glaze should be the consistency of milk, cream, half-and-half. I found this maddeningly imprecise, and a real problem when painting on vertical surfaces. Too thin a glaze coat, and the base is brown and unattractive from the iron in the clay body, but too thick, and the picture runs off the pot. After far more years than I'd like to admit, I finally bought a hydrometer. It's a glass tube, like an oversized thermometer, with a lead weight in the bottom and a paper scale, graduated to measure specific gravity. After mixing the glaze thoroughly and waiting for it to stop spinning around in the bucket, I lower the hydrometer into the glaze and let it float, then read off the scale where it's at the surface level. The specific gravity of water is 1.000; I've found 1.500 works perfectly for me. (As an aside, this means there's twice as much water as dry materials in my glaze, so for my standard batch of 14,000 grams, I'm actually mixing up 42,000 grams of glaze--a bit over 90 lbs.)

 I also find that the glaze gets thicker with use, whether from evaporation or absorption of water into the bisque, so I check a couple of times a day, and add water as necessary.

Thickness. The thickness of application of a glaze depends on several factors: how you apply it, for how long, and how much water the pot can absorb. I dip or pour the glaze--spraying leaves too fluffy a surface for my overglaze decoration--for a count of four (one, two, three, four--out again), which I long ago determined is actually about three seconds. Apparently, I count in waltz time, 3:4. Smaller pots, especially thinner pots like soup or toddler bowls, may need a little more time in the glaze to get a proper coating. I usually dip lids for casseroles, cookie jars, honey pots twice to get a proper coating.

Settling. If the glaze isn't fully suspended, you're not going to get an even coat. If your glaze is high in slightly soluble minerals, like nepheline syenite, it'll want to settle to the bottom of the bucket and form a rock there, while leaving just enough in suspension to fool you into thinking you're still applying glaze. Mix early, mix often. And a teaspoon of epsom salts, and a bit of aging, doesn't hurt either. I now mix my glaze for each firing during the previous firing--four to six weeks before I actually start glazing again. The extra conditioning time does wonders for glaze suspension.

Overglaze application. If you're used to underglazes, you're gonna put the stains on too thickly. You want it the consistency of india ink, maybe a little thinner. And that's for the initial line drawing, at full strength. Dilute with water to create washes, shadows, lighter tones. There's almost homeopathically small quantities of red stain in the water when I glaze bunny ears. I want only the palest of pink. Some colors have more tinting strength than other. Cobalt carbonate can be diluted many times and still give you blue.

If your stains are blistering, or, worse, burning out to a scabby grey scale, you'll really want to dilute them down some.

Firing temperature. There's a lot of variation in the way potters fire to cone 10. I know a potter who fires cone 10 flat on the pad, 11 nearly touching down to get the glaze effects he wants. If I did that, every picture on every vertical surface would be a blurred smear. I want cone 10 just touching at its tip. If the kiln is firing unevenly, I may fiddle with the damper to try and catch up the cold end, but not past that point. I can usually count on carry-over to drop that last half-cone, particularly if the top of the kiln is cooler than the bottom at shut-down.

Other firing ranges. I'm firing cone 10 in reduction; I've also used cobalt, iron and rutile at cone 6, reduction. Not sure how they'd work in oxidation; some metals, iron in particular, act as a flux in reduced form, but a refractory in oxidation. Experiment with a reliable white/whitish base glaze, moderately glossy, and be prepared to add Gerstley Borate or Ferro Frit 3134 to your oxides and stains. I wouldn't overglaze on a matte glaze if I intended to use it for food; I'd worry that the oxides wouldn't be sufficiently absorbed into the glassy matrix.

En route

So Denise is home from our vacation already, back in Eugene. I'm taking the long way around. Driving.

She inherited her mother's car back in January, and was also in Wisconsin in February; neither are good times to drive a nearly-new car cross-country to Oregon. So here I am in Billings, Montana, two days out from Milwaukee, with another two to go.

Didn't expect to run into anything ceramic to write about (though this little fella, found at a rest area just into Minnesota, has a fairly convincing raku copper luster).

But a little past Jamestown, ND this morning, I answered the call of excess hydration, and found this at the rest area. The display inside is devoted to the building of North Dakota's stretch of the interstate highway system, which apparently they finished ahead of everyone else (possibly because they had to do so little earth-moving to achieve a level grade).

The facade of the building continues the theme with this lovely, carved-brick relief sculpture featuring crane, jackhammer and the first piers of a highway overpass. I suspect the bricks were made in Hebron, ND (self-proclaimed Brick City), just a short drive west. Denise and I camped there once on a trip west, and were surprised to find that the very red gravel roads weren't granite (as in my home region of Wisconsin) but clinker, naturally fired chunks of red clay. They're created when layers of lignite--soft coal--ignite in the ground, and fire the surrounding strata of mudstone, naturally occurring clay.

You can see this writ large on the landscape at Painted Canyon, part of the Theodore Roosevelt National Park, a little further along my way. Red tops of the mounds are the fired clinker, which resists erosion better than the still-water-soluble layers of clay underneath.

There but for...

quiet, beautiful pots
Ever since my high school art teacher expressed surprise at my intention to major in art in college, I've had a bit of "I'll show 'em; just you wait and see" in the back of my head. (In Miss Guenther's defense, although I was a pretty good art student, I was also valedictorian, math league champion, and took a first at state in extemporaneous speaking. I wasn't spoiled for choice, academically, and in fact I had a double major in Art and Math when I finally graduated from Viterbo.)

So while I intended to show Tim and Mary what I was doing in pottery these days, there was also the secret urge to show off that I was doing it, and doing it well. Making my living as a potter.

It was during a rambling conversation about life in the booth, the Please Touch rule, and all the stuff that's tagged here as Marketing 101, that Tim quietly said, I never really learned to sell my pots.

And I stopped dead.

I mean, it kinda makes sense. When you're on a college faculty, they look more at your exhibition record--how many shows you've done--rather than how well you've sold at them. Add the fact that your time is divided--if you're a good teacher, it hugely impacts how much time and energy you have for your artwork. And if you're not naturally gregarious (or business-oriented) and trying to sell art pots--basically a specialized form of sculpture--it's easy to never quite crack that nut.

That could have been me. Just out of grad school, applying for teaching jobs, not very outgoing, and crap at self-promotion, if I'd actually landed that tenure-track position, I might be saying the same thing now. (Though maybe not. The story tiles--narrative sculpture in a handy, table-top format--I was making in graduate school had a fairly broad appeal. I think I sold more from my thesis show than any of my classmates.)

But we'll never know. The only teaching job I ever got was a part-time affair that required I take a production gig to make ends meet. That experience gave me the skills to make and sell my own work at Saturday Market. Weekly practice there taught me what would sell and how to sell it. And gave me the first few steps towards moving out into the greater fair circuit, where I am today.

Tim's retired now, still making beautiful, quiet pots, but he's left the marketplace. Mostly, he gives his pots away, to people he thinks will appreciate them. These two beauties are coming home with us.
The interior of Tim Crane's wood/salt kiln. All that shiny brown glaze is decades of ash and soda deposition from wood and salt glazing.
stuck pot optional
And yes, that is a pot stuck to the back wall. He had a shelf collapse in his last firing, and that brown glaze is plenty sticky when the kiln is hot.

You can go home again

I've never really had a mentor.

Wasn't really close to my professors. Only met with my graduate committee twice in three years. It may be I'm too independent (bull-headed, my father would have said). But I think there's also a healthy dose of reticence, a holdover from the shyness of my childhood. I'd rather figure something out for myself than bother someone else, asking for help.

So it was with some trepidation that I got in touch with my Viterbo pottery professor and his wife, Tim and Mary Crane, about visiting them while we were in Wisconsin. Sure, Mary encouraged us to stay over. We have a guest room! Do you have any food preferences? How long can you stay? But I still didn't want to intrude. Didn't want to be a bother. (I'm so Midwestern sometimes.)

So glad we did.

The conversation went all over the map. Pottery, of course, and "Where are they now?" reminesces. But art in general, literature, college and life experiences. I showed pictures, they showed pots. Visited the wood-salt kiln, still there after 35 years (though the kiln shed had burned down in 2014 and been replaced), the studio, showroom. Went for a long walk along the ridge--they still live in a rented house beyond two fields and three cattle guards--looking at birds and plants and other points of interest (Wolf scat? You have wolves?). And the beautiful rolling hills of SE Minnesota.

They also invited Tim's ex, Diane (who also taught me at Viterbo) and her partner Bets to dinner, where the conversation started all over again.

We left with a stack of books (including a noir trilogy set in La Crosse), a couple of pots, and an open invitation to come back... and some wonderful memories.

Six words

Staying with friends whose bathroom reading included Not Quite What I Was Planning, a collection of six-word memoirs, so I decided to try and write my own.

It took a couple of tries--for some reason I kept coming up one word short--but I finally got one I'm satisfied with.

I made your kitchen table happy.

On the other hand

Most potters in the world (Japan excepted. Don't ask me why.) throw with the potter's wheel turning clockwise.

But I'm left-handed. I grew up in a world of Of course,  that's if you're right-handed. Left-handers reverse these directions. So when I first started to throw, I kicked the wheel clockwise.

If the regular pottery professor had been teaching, or if Viterbo had had electric wheels, it might have been otherwise. Throwing is very ambidextrous,  equally easy (or difficult. For me, more the latter) to learn turning either direction, and back then, few electric wheels had a reversing switch. But Tim was on sabbatical, Jan was occupied with teaching an unfamiliar class, and the studio was committed to Leach-style treadle wheels, so by the time anyone noticed, I'd gotten used to the direction I was throwing.

I continued throwing on kick-wheels, left-handed, after college, all through graduate school, and into my days at the Craft Center. I did teach myself to throw counter-clockwise as a teaching assistant in grad school, the better to do demos, but it never came as easily as clockwise.

Fast forward to my days with Slippery Bank Pottery. I was committed to making nine dozen hummingbird feeders as week, while continuing my teaching load. Kick-wheels weren't gonna make it.

I mentioned Japan earlier? For some cultural reason, right-handed potters throw clockwise there. Fortunately for me, the Craft Center had a Japanese-made electric wheel, an old Shimpo that nobody used much because the speed control was either a very stiff, inconveniently placed pedal, or the attached gearshift-style lever. It quickly became my wheel.

Wheels with reversing switches are more-or-less standard these days, so I guess I'm not the only lefty out there. I have two electric wheels now, a Pacifica with factory reverse and an old Soldner with a switch bodged in by the previous owner (who I once made hummingbird feeders for). But I still get the occasional confused look as I throw, from spectators who aren't quite sure what's different, but know something ain't right.



Time travelling again


Visiting my brother in Wisconsin, which, in addition to revisiting embarrassing family stories, allows me to revisit embarrassing pottery.

Actually, it's not that bad. A lot of the pottery I've given him over the years is still recognizable: a large bunnies serving bowl, robin cookie jar, batter bowl with the happy hen pattern. This one, though, goes way back. Not quite to my Wisconsin days, I don't think, but certainly pre-Off Center Ceramics.

It's an oval baking dish, about 6x9", glazed in Craft Center temmoku and Woo's blue. I did a lot of these, early on. The walls are thrown first, with no bottom, then formed into an oval. At soft leather hard, a slab bottom and crock-style handles are attached. Can't tell if these handles were pulled from a (very small) coil, or whether they were thrown and then cut and attached. They're a little small for practical use, almost dainty.

I still use this technique to make oval platters, but not bakers. The failure rate was too high both in the making (cracks along the seam if moisture wasn't correctly matched between bottom and sides) and, occasionally, the baking. Apparently, a slight mismatch in moisture, not great enough for cracking, might still introduce stresses that would show up when they were heated in the oven. Much safer to go with my current, squared bakers: thrown in one piece, deformed slightly while still wet, then pulled handles attached at leather-hard.

Though this is a pretty, pretty pot.

Microclimate


Weather continues weird and unpredictable. Friday became surprisingly sunny by mid-day, though occasional grey, cold fronts blew through. Saturday,  predicted sunny, was overcast all day, and turned to rain for several hours around supper. Today looks to be grey most of the day, though chance of actual rain is supposedly small.

And that's the other problem. The forecast changes from hour to hour, and from forecaster to forecaster. Everyone has a favorite source, sites or app, and none of them agree. Worse, the weather changes drastically in the five miles between our motel and the fair. Microclimates.

We have a lovely bunch of neighbors this year, unlike last time, when we had to listen to a pair of vendors complaining through the back of the booth all weekend. Only problem is that all of them--with the exception of the porcelain jewelry lady to our right--are art objects. Paintings, mural landscape photography, silk scarves, high-end fused glass. Harder to sell than painted pottery, especially when the potter has a head start--120 postcards and e-cards sent to previous customers before the fair started. I've said before how much I rely on repeat custom, and that was really evident on Friday, when I had a very good day while everyone else was dragging. Saturday picked up for them, thankfully, and while I had fewer customers, individual sales were slightly larger, so I ended up within $30 of Friday's total.

It's tricky having a good sale while your neighbors aren't. You want to feel good, celebrate it, but you don't want to be that guy, the one who brags about his success when everyone else is failing. So you go all Midwestern. Oh, we're doing okay. Not bad, y'know. Can't complain.

Hopefully, Sunday will bring sale to everybody. Us included...

Setting up in the rain


...is a lot like getting dressed inside a sleeping bag. You keep shifting stuff around until you find the next thing to put on.

Up at Edmonds, setting up in a drizzle. The show takes place on a baseball field, with one way in and one way out, so setup is incredibly organized. Regimented, even.

To begin with, it's divided into two-hour blocks. First in are the over-sized folks, people with trailers and so forth. Next come the south-facing booths, then north-facing booths, then all the corner booths along the main concourse. Last shift is a pick-up period for anyone who missed their time, and God help anyone who shows up with a trailer. You've got forty-five minutes, tops, to get everything unloaded and your vehicle offsite. We managed it in under thirty.

Even within this structure, there's fine-tuning. We figured there wouldn't be that many over-size, so arrived fifteen minutes before our time, got in line behind three other vendors and gave them our booth number. When they radioed ahead to volunteers on the field, they found room at our space, so pulled us out of line and sent us ahead. They do something similar at load out, necessary because the queue runs six or eight blocks at that point.

In any event, we parked in front of our spot around ten of ten, immediately set up the canopy, then I hustled in boxes of pots while Denise shifted shelves and stands. At 10:23, I was backing and filling to turn around and cut across a neighboring space to move out and make room for the next vehicle.

Setting up... well, on a dry day, we'd have put stacks of pots out front, or in the empty north-facing booths behind us while we assembled shelves. Today, everything had to stay indoors, so it was a lot like those sliding tile puzzles, or, as I said, like dressing in your sleeping bag during winter camping.

Still, aside from rain blowing on the edges, we managed to keep everything reasonably dry, and got things out and organized to the point where we could leave the rest for morning by a little after one pm, including a lunch break. Ran a few errands, gassed up the van, and had a leisurely afternoon in our hotel room, listening to someone's lonely doggie crying, down the hall.