Sunday, March 29, 2015

Fast and Easy

When you google "fast & easy" you get mostly recipe links. But one of the phrases google suggested to me was "fast and easy ways to get pregnant."

Um. I guess I thought the fastest and easiest was the one everybody already knows?

None of that has anything to do with this post.

I just wanted to say, this firing - the one that went off an hour and a half ago - was the fastest and most even firing I've done in this kiln. It was a ^10 firing - the ^6 ones are quicker, of course - and it took 11 hours. I candled overnight, but started turning the burners up around 7 AM, and it went off at 6 pm. That has never happened before!
I just changed one tiny little thing.

It's always scary to change something about the way you fire, if you have a way that works reasonably well, because if you try to improve on it, you can make it MUCH worse. And then you've lost a month's worth of work, because you just had to go experimenting!
In this case, this kiln has always fired unevenly - hotter on one side than the other. At first blush, you might say, Well, duh. It's got two burners on one side, and only one on the other. I guess that could be it, but it's a pretty small kiln - maybe 22 cf - and I have fired many kilns with two burners at the back and none at the front, and those can be perfectly even. So I was never completely satisfied with that explanation, but I didn't care that much, because the kiln was giving me good pots.

Not sure what possessed me to try and change it this time. I knew the kiln on the one-burner side always had much heavier back pressure, and I knew that a reducing lame produces less heat than an oxidizing flame, and this effect becomes more pronounced the heavier the reduction. The primary air was already all the way open, and I couldn't easily change the secondary air - the ports are hardbrick. But just today, I thought: the soda port.
My ports are low, so I can dump the soda mix right into the burner channel. Maybe low enough, I thought, to serve as a kind of secondary secondary air. Tertiary air?
Just pulling the brick didn't work; that side of the kiln lost all back pressure. Instead I found a fraction of brick and blocked a little less than half the port.
Perfect! I got a long steady flame, bright orange, no smoke, on both sides of the kiln.
Oh, I lied. I said I only changed one thing but I just remembered I changed another. I started to wonder if I could manipulate the flow of air into the kiln using the passive damper. Not just control how much, but where. So I blocked just a couple of inches far to the cool side of the damper.

Not sure if one or both of these adjustments was responsible, but the kiln climbed quickly and evenly right up through ^8. Got a little uneven after that, but not out of hand. I drew a line to indicate the position of the damper, and the brick blocking the passive, so I can find the sweet spot again.

Unloading this kiln on Wednesday.

Loot from the Conference

I saw so much over the last few days, my head is swimming with ideas - which I guess is the point of NCECA. I took a bunch of photos, but I need to go through them and attach the correct names to the works, and then I can share them.

Seeing work. Watching demos. And let's not forget SHOPPING! Part of the fun of the conference is getting some new tools that send you back to your life dying to make something with them. I got:

  1. A couple of sprig molds from the Marvelous Molds company. I do prefer to make my own sprig molds but these looked so much like something I would have made, I couldn't resist. I'm saving the link because I'd like to get some for soap, also.
  2. A roller from MKM Tools! Again, I make myself tons of rollers, and I don't love most of those wooden laser-cut ones - the patterns read as quite mechanical. If you use them sparingly, though, they can be a nice counterpoint to a squishy or wonky pot, in the same way the a tight, architectural thrown rim works when you then twist and bend it out of round. This roller had a delicate floral pattern that I thought would work well with some of the bolder, slip trailed floral stuff I've been doing.
  3. Underglaze chalk - I got three colors. I had a black one, which I got from Portland Pottery, and I was impressed by how well the detail of a soft charcoal-like drawing is preserved under a clear glaze. I had been meaning to get more colors to test out, anyway.
  4. Brushes - some fine line camel-hair brushes, and a set of acrylic-bristle brushes to use with latex. There is nothing special about these brushes, except that the set of six brushes was only $2.Latex resist destroys brushes pretty fast no matter how careful I am, so it's good to have some cheapies.
I have lots more to say about the conference - what worked, what didn't, best moments - but I am firing the kiln load right now that got delayed due to high winds last Sunday, and I need to go and peek at the cones. I'm also getting the house ready for our Central Maine Clay Artists group to come over, where we'll divide up the mugs to be distributed for Mug Season, our annual fundraising event for local arts programs.

Aaaand, cone 3 is flat so I better start mixing up the soda salad.

Monday, March 23, 2015

Mad Dog Shino

Now you'll recognize me at NCECA
One nice thing about working at Portland Pottery is I always get a handful of pots out of each kiln load. I don't fire all my demos - I'd be buried in a mountain of not-quite-polished pots - but every firing there are a few.

This one is a trick I love to show students. It's Malcolm Davis Shino, onto which I brushed liquid wax resist...and then didn't do anything else. Just glaze, then wax. No second layer of glaze, no water sprayed on, no sponging.
The mug, before firing

It's the only glaze I know that will do this. The wax prevents the soda ash from rising to the surface of the glaze, and then provides carbon for the glaze to trap as it burns off, creating the contrast between the waxed and unwaxed areas.

It's a highly changeable glaze, its results varying wildly from firing to firing, prompting my students to proclaim that the "M.D." on the bucket stands for Mad Dog. It was a good dog this time, though.

Perhaps because of the high percentage of Neph Sy in the recipe, MD Shino has performed well for me. with NO alteration, at ^6 also. Here's the recipe:

Malcolm Davis Shino
Soda Ash                     16.3
OM-4                           13
EPK                             17
F-4 Soda Feldspar         9.3  
Neph Sy                       38.6
Red Art                          5.7
This version is best on white clay; for a version for brown clay, just out the red art one-for-one with EPK.

Sunday, March 22, 2015

Mariah Blows the Stars Around

They may call the wind Maria; I call it a giant pain in the ass.

Though it was slow to get rolling, I was very excited to finally be firing. The past winter had not been conducive (not that the so-called "spring" has been a hell of a lot better so far!) but I finally got the kiln loaded and candled overnight last night. I started turning burners up around 4 am, to get the wax burned off before light, so it wouldn't worry neighbors and passers-by; but by 10:00 am I knew I was in trouble. The wind was gusting hard, and picking up.

This isn't a problem for the reason a lay person might expect, that the wind makes everything feel colder. It's not appreciably harder to bring the kiln to temperature in the 12°F than in 70°. The wind does affect how the flame moves around the kiln, though, and high winds cause my kiln to draw too hard. The wind essentially sucks the heat out the stack before it can do its good work inside. Not all of it, of course, and not immediately, but the kiln will climb very unevenly, and the bottom will be a lot hotter than the top. 

I looked up the forecast and found that Augusta has a high wind advisory until 8 pm tonight, so my feeble optimism that perhaps it would die down was misplaced. Nevertheless I spent an hour arguing with myself about whether to abort the firing. I've already invested several hour of propane! The winds are not as bad as that time the firing was really really awful! Maybe it will be okay! I won't be able to complete this firing for a whole week if I bail now!

Yeahno. Sure, it might turn out alright. But what's the point of experience, if you don't learn from it? Experience tells me that this firing will either burn way more propane than it should, or turn out badly, or, more likely, both. What's to be gained by continuing? Yes, postponing will make a delivery late, but guess what? That delivery is also going to be late if the pots are bad and either have to be re-fired or re-made entirely.
I am aggravated about this, but was there ever anything so futile as anger at the weather? I'll just take out my frustrations on some dust bunnies and coffee stains. Then I'll start packing for NCECA! Just typing those words helps my mood. 

On the topic of wind, Harve Presnell has a few words to add.

PS. Is there really a place where people call rain Tess, or fire Joe? "My Joe was postponed due to Mariah?" "Looks like it's going to Tess tonight?" YEAH I KNOW IT'S JUST A SONG. Enjoy.

Saturday, March 21, 2015

Maine Pottery Tour Update

This is the time of year that my life gets eaten by preparations for the Maine Pottery Tour, and that's doubly true this year, as the tour has doubled in size, plus some.The whole-tour map is finished, but I'm continually updating the website and still need to create flyers, posters, and postcards. It's going to be the best one yet, no doubt. There are 40 stops on the tour this year:

It's kicking my butt, though. I always forget how much work it is! I started working on pottery tour stuff when I got up and I just looked and four hours have gone by. That's enough for today.

I do still make pottery! I am loading my glaze kiln today, and firing tomorrow. I may not get a chance to unload it before NCECA, so I'm excited to go, and I'll be excited to get home.

Wednesday, March 11, 2015

Sling & Slip

Though I'm in the firing end of the making cycle in the studio, I am still doing wetwork demos for my classes. This platter is made by securing cloth over the top of a container and then draping a thick slab over it. Some call it a sling mold (say this in the voice of Billy Bob Thornton.) I like sling molds because any size platter you want to make, there is a container in the world that will serve as the mold for that platter. Look in the home storage department at Target for larger ones, or in the food storage aisle at the grocery store for smaller ones. This one if held in place with rope but a big rubber band would work or, if your mold is wood or cardboard, you can staple the cloth in place. I leave the clay quite thick - maybe 5/16ths inch. I hate a flimsy platter.

If I catch this platter at the exact right moment I won't need to put a foot on it: I can just take it out of the mold and tap it on the tabletop to flatten the bottom. If I miss my moment, I'll throw a ring for the foot.

It was two demos in one: I showed my students how to make the sling mold, and then used the platter I made to show them a couple of slip techniques. The checkerboard pattern I made by cutting squares of newspaper and sticking them to the damp clay, then brushing white slip over them; the flowers are a brush embroidery technique.

But that was yesterday, and yesterday's gone. Today I a back in the glazing/firing end of the cycle. I'll be applying flashing slip and waxing pots all day.

Friday, March 6, 2015

Wheel Week at Cony High

Every year, my town's high school ceramics program hosts potters for Wheel Week, in which each of five potters spends a day throwing and talking to the students about clay, creativity, and being an artist. Today was my day! Wheel Week is always fun for me; the kids ask great questions, and the school is in my neighborhood, so many of them know about my studio, or have seen the pottery stairs in my yard during the warmer weather.

In other news, we adopted a new cat today! Doug and I had agreed to bring another fur friend into the mix, and today I chose a big black and white kitty. He was named Survivor at the shelter, but I am thinking we will change that; whatever it was he had to survive, those days are past him now. It's Easy Street from here on out. He's a timid guy, and reminds me very much of Waldo. So far the other cats have not had much reaction at all, which is all to the good, since cats' first reaction to a new feline is usually hostility. I'll post a photo after he has had some time to adjust.

ETA:  Here he is! Still hiding but he did eat a little bit this morning. Baby steps!

Finn McCool

It's almost spring, and time for new beginnings.