What's inside?? I hate not knowing

 Man, I was not even lying when I called this the Murphy's Law firing! Let's have a brief recap of all the things that went wrong, chronologically:

1. I originally planned to fire Wednesday BUT, though I candled overnight, first one then the other of the pilots fluffed out. I caught the right one pretty early, but woke up to the left blown out around 4 am.
2. I made the fateful decision to relight & candle for only another hour before turning the burners proper on
3. This is a big one: THE CONE PACK BLEW UP. 
4. I let the kiln cool & unloaded the entire thing to eliminate the cone pack debris, reloaded, & rescheduled the firing until Friday (today)
   
5. I thought I had left the hex (or whatever it was!) behind, because this shaped up to be a picture-perfect firing, just like the July firing was. Humming right along. 
6. Yeah no
7. Halfway through the application of the soda, the sprayer stopped working. Not clogged - that I could fix. Just wouldn't take on any pressure, so couldn't spray. At this point I had a gallon of soda mix left and cone 9 was over. 
8. What to do, what to do?? It might be fine as is, but it might not! I left Doug to keep an eye on the kiln & started driving around town looking for a suitable sprayer, with a metal wand. I had NO luck with this. 
9. But I did find a little hand-held pump spray bottle, which I hoped might serve to get the soda into the chamber. But the time I got home 11 was over up top & ten was down on the bottom. 
10. I sprayed the rest of the soda anyway. I dunno how well it worked. By the time I finished & gave the soda time to vaporize & burn clear, eleven was flat all around. Like, flat-flat. 

​

Details matter! The image is of the gap between the kiln shelf & the bottom of the pot, which is raised up by three wads of high-refractory clay material (called wadding*) which prevents the pot from sticking to the kiln shelf when the soda coats everything in the chamber with soda glass. After the firing, the wadding just pops off, leaving pale marks where it previously stuck. 

I find the higher this gap is, the more glaze gets deposited on the bottom, creating some color & sometimes a bit of shine. The wad marks - pale dots where the pot rested on the wadding where no soda vapor could get deposited - are often quite handsome. 

Wad marks on a mug

Because the wadding is basically wet clay, the weight of the pot tends to squish it almost flat. It will still do its job of preventing the pot from sticking to the shelf, but the bottom won't get any soda, so will just be white. Not the end of the world, & not the end of the pot, but I do like the ones with more distinct wad marks better. 

To achieve this, I find I have to make the wads ahead of time, so they are a bit drier & stiffer when I place them on the pot. I can't make the wads too early, because if they dry to much, they won't stick to the bottom long enough to get the pot into the kiln. Like a lot of things in clay, the pots are fine if I don't do it, but they are just a little bit nicer when I do. 

Speaking of things that I should really remember to do ahead of time: I was supposed to fire today, & I would have, except my cone packs exploded! Regular readers must get tired of hearing all the ways I manage to screw up, but maybe you can draw inspiration from it: If a ginormous fuck-up like Lori can do this, so can I! Actually I don't know if I screw up more than most people, but since I am a ceramic educator as well as a potter, I believe in being open about my mistakes. I make em! A lot. But then I fix em & move on. 

The culprits. You can just tell they are plotting something.

I fixed the exploded cone pack by unloading the entire kiln to dump out the little bits of debris inside the pots, then reloading the whole thing. I was mad at myself at first - the exploding cone pack was definitely caused by my dumbness - but it's summer in Maine, I was outside, the birds were singing, & loading kilns is fun! If that's the worst mistake I make this week, I can live with it. Anyway, the last firing was absolutely picture-perfect, the cones falling in synchronicity, so I was overdue to have a Murphy's-Law firing. 

Anyway, once I got over calling myself a moron & started enjoying the work, I decided that, far from a moron, I am in fact a genius! (LOL ALL DAY) Or at least reasonably clever in this instance, as I realized that when I scheduled the firing I built in some time in case something goes wrong! So I'm still on schedule. 

Barring some other mishap, I'll be firing this load on Friday, probably unloading Monday. I hope to have new work in the online shop on Wednesday! 

*Wadding Recipe

1/3 Kaolin

1/3 Alumina Hydrate

1/3 Coffee Grounds

So, a weird thing happened this morning. 
I candled my bisque overnight, but when I came out in the morning to turn on the burners proper, I found flame coming out of the primary air intake of the pilot. I had never seen this before & immediately turned off the gas - that's kinda my go-to move whenever anything unexpected is happening with the propane. I wish I had taken a photo to illustrate this post, but oh well. Probably anyone who would know the answer already knows what the primary air intake looks like.

The only difference I could observe between the pilot that was behaving normally & the one that was doing this unusual thing was the primary air intake was open a little wider on the odd one. That one was also a little harder to light last night. I don't remember opening or closing either of them but who knows? 

I spun the disk to close the intake a little more, so it matched the other, then re-lit the pilots. Nothing unusual happened after an hour, so I went ahead & lit the burners. 

Anybody have any ideas why that happened? I'm not gonna blow myself up, right?

​

After fumbling around a bit early in the firing- this is only the second time I’ve fired this kiln, due to some unexpected burner issues- I’ve found a sweet spot of good reduction & rapid climb. Just recording it here, for future reference.

It’s been a rough couple of months, which I’ll tell ya more about later, but something finally went right.

This load is about half my work & half student work. Unloading Wednesday!

 You always have to learn a new kiln. The sound of the burners, the length & color of the back pressure, the reduction smell - all those things re going to be different in a new kiln. This kiln is notably different, as it has power blowers, which have their own sound & affect the appearance of the flame. 

I am firing without any of that gained intuition.

 

The first part of the firing went ridiculously fast. I got up early, not knowing how long the firing might take, but 012 was down by 6 am. I stalled it out a bit during body reduction, trying to get a flame from the low spy, & spent an hour or so monkeying around with the burners, the blowers, & the damper, trying to get it to climb without re-oxidizing the load. Eventually 05 fell, & I could back off the reduction again (although, who knows? Reduction itself looks different) & it began to climbing startlingly fast - ^3 has fallen up top. At 8:30 am. 

I pushed the damper in a bit, to try & push some of the heat downstairs, which has had the effect of slowing the climb. That is probably a good thing! I might try backing off the burners a bit & pushing in the damper a bit more. So many moving parts!

Ok, did that...I'll pop back out in a bit to see the effect. Normally I clean the house & the studio on firing day, but today the kiln needs too much of my attention. 

^6 falling at 11 am...

 

Also in that kiln, work for the upcoming group show at Monkitree, Exploring Maine: A Maker's Journey. Here are the pieces (probably!) for that show. 
Additionally I have pots for the Portland Pottery Café, pots for Bayview Company, pots for Mainely Pottery. 

The week leading up to a glaze firing is always a busy one at Fine Mess Pottery. This one is compounded because we are less than a month out from the Maine Pottery Tour - I am working on the flyers right now. Did I tell you how much I hate that job? I am determined not to do the thing where I dread a task for longer than it would actually take to do the task, so I hope to have those finished today. 

Wednesday, Thursday, & Friday were glazing days. In accordance with Hofstadter's Law, glazing always takes longer than I think, even when I take into account Hofstadter's Law. My glazing is (usually) a

several-step process: trailing, waxing, dipping, pouring. I really go through the wax! I find that the flashing slip is smoother & glossier after firing where it has been waxed. I do not have a good explanation for this. 

I also needed to prepare the kiln shelves. Between every firing, I have to scrape & grind the kiln shelves, because the soda vapor makes glaze on them as well as the pots! I also do not love that job but again, if I eliminate the period of dread before I begin, it's over before I know it. 

Pre-made wads

This firing I glued on some of the wads in advance. The other wads I made up ahead of time & stored in a lidded plastic container; this makes loading go faster 7 helps keep my hands clean, so I don't get wadding smudges on the pots, or have to keep dipping my hands in water on a cold day. 

This had an unanticipated benefit; the wads were a little bit stiffer than usual, which meant that I could use taller wads that would not squish down with the weight of the pot. Taller wads mean more soda glass on the bottom. Bottoms matter! 

I space the pots with about 1.5 inches between them for better soda distribution.

Then, the actual loading: it's always a push-pull between "get lots of pots in" and "leave plenty of space between them." Lots of pots, of course, has the benefit of being lots of pots! Plenty of space between has the benefit of better soda
coverage. I want as many pots as possible, but if I have to choose between "more pots" and "better pots," I know which one I want. 

NO SHELF-SHAMING😉 If it still works I use it

I finished loading yesterday around 3. I take plenty of breaks, because I know from past experience that just powering thru will give me a sore back the next day, when the actual firing
will be happening. I got everything in that I needed to - yay - with some pots leftover for the next firing, also yay! Because I need to make, bisque, glaze, load, & fire so I can have an unloading even Saturday, May 1 for the pottery tour. 

The kiln is at ^05 now, in a light reduction. Probably about 7 hours to go. 

God, I'm tired. 

Oh, & happy Easter, if you are celebrating! 

I put off unloading, because Friday & Saturday were so bitterly cold, and because no one is waiting for these pots. Today warmed up to a near-balmy 23°, sunny and perfect for unloading. Right off the bat, I suffered the traditional unloading nick, which bled like a mad bastard until I finally gave in, went inside & got a bandaid. 

As inevitable as the nick is the loss of a few pieces. Some firing processes demand more sacrifices to the kiln gods than others; these pots got some bits of wadding crumbled into them from between the bricks of the door. (Not sure why there was more crumbling than usual. I'll have to think about that.)

In the past I might have argued with myself that I could dremel out the bits, apply more glaze, and refire; or that I should save them for a magical someday when I will have time to make a mosaic with my broken pieces; or that I should place them between plants in the perennial garden. Now I'm just like, Nah, toss 'em. The sooner they are out of my sight the sooner they don't matter. If I saved all the pots that didn't work out I'd be surrounded by now, obstructed in every direction by buckets & boxes of unusable pots. Letting go is a valuable skill, for a potter. It's one I teach my students, when their handle separate or their rims crack: let it go. Take the lesson & let the piece go. Make another one. I try to live my own advice. 

Otherwise the firing was pretty good. The very bottom layer was a little pale - I stacked differently, and it affected the way the soda vapor moved around the kiln. (I don't have to let go of those, because they don't require any additional work from me - just load em in the next kiln as if it were the first time.) Mostly mugs & pasta bowls, a few dip dishes & berry colanders. Bread & butter ware, so to speak, although no actual butter dishes. 

Speaking of actual butter dishes, I have some in progress that need assembling, so that's where I'm headed now. 

Lookin' for some hot stuff, baby this evenin'
I need some hot stuff, baby tonight
I want some hot stuff, baby this evenin'
Gotta have some hot stuff
Gotta have some love tonight...

If I didn't clarify before, my last firing was only a Murphy's Law firing if Murphy's Law was about screw-ups. Everything that went wrong in this firing was something I did wrong or failed to do! It's something of a pattern: I have a few super-smooth firings in a row, then I get over-confident - or maybe lazy is the word I want here - and make things harder for myself. For example:

• The cone pack exploded because 

1. I made the packs just a few hours before lighting the burners
2. I didn't poke vents in the clay of the pack with a needle tool, to allow the water vapor to escape more easily; and
3. I turned up the burners too quickly

• The burner fluffed out repeatedly because the thermocouple was failing. That's nobody's fault - thermocouples don't last forever - but usually I have extras around. 
• I forgot to buy wood shavings and soda ash ahead of time
• And, as I was reminded when I unloaded, I forgot to do my basic kiln hygiene and knock the stalactites off the underside of the arch! These turn into ugly, lumpy grey-green drips in the firing, and I lost some pots on the top shelf to them. 

My last firing was smooth sailing all the way - a high pressure day, a steady climb, body reduction by 7 am, all the pretty cones falling evenly. The universe demands balance! So this firing takes Murphy's Law as its inspiration. A cone pack explodes! A burner fluff out, twice so far! Ooops, I'm out of wood curls! Pelting rain last night right when I had to adjust the burners!

It's not promising. I'm tempted to turn it off & try again on Wednesday.

But that's silly! There's no reason this annoying firing can't produce beautiful pots. and firing on Wednesday would put a squeeze on an already-tight timeline for my upcoming fair, Belfast Art in the Park. So I'll just keep an eye on that f*cking burner, send Doug out for wood shavings, and hope for the best.

Ugly pink bisqueware! But it will get better. At least I hope it will.

With just over a week left before the Maine Pottery Tour, I am scrambling to get a firing cycle completed. It's a nice problem to have - I thought i had plenty of inventory, but sales over the winter were better than expected, so I need to squeezed out enough to fill the shelves. Today I have two classes to teach, so I may not get much studio work done; Friday & Saturday promise to be glazing marathons, in order to fire on Sunday. If that doesn't happen, I may quite accidentally be including a kiln opening as a tour event on Saturday morning! that wouldn't be the worst thing, although, given how disappointing my last firing was, it's a bit of a roll of the dice - I wouldn't want an audience for the unveiling of a crap firing.

On the other hand, people DO love an unloading! And it's not like i have no pots, I'd just like more, to give the shelves that compelling sense of abundance that makes people want to take some home with them.

Probably my best plan is to shoot for firing Sunday, then, if need be, I can push it back.

So much to do!
Local peeps - all of you peeps, actually - I hope I see you! May 4th & 5th.

I always think I am going to get tons done during a firing. I have all day, and I have to be home for the kiln! In practice I'm lucky if I get a couple of loads of laundry done, and maybe scoop the litterboxes. The flame is so pretty! and I am so tired form the couple of day so intense work that precede the firing.
Here's the back pressure shortly after adding the last soda load for this firing. Just waiting for that last cone to fall now.

Chillin' indeed; though the calendar says it's mid-April, the weather says it's more like the 109th of January. Nevertheless anytime is a good time to hang out at Watershed; it's a magic place where magic things happen. Well, sometimes.
I was firing at the 'Shed because the arch of my own kiln needs some work; after the last glaze firing, a tie rod broke and the arch spread a bit, causing a few brick to slip out of the curve, like snaggly teeth. this repair promises to be like a lot of jobs - begun is half done...but I haven't begun yet, and it's unlikely that I will before the Maine Pottery Tour. I did go ahead & bisque in it, with no noticeable difference. I am tempted to try a glaze fire, but I need to shoo that lazy demon off my shoulder, and listen to the angel on my other shoulder that says I might as well fix it instead wait until it causes a real problem.

Now you see 'em...

Now you don't!

I loaded & bricked up on Thursday, and fired on Friday...today is technically my day of rest! HAHAHAHAHA as if. Today I am doing all the housecleaning that gets neglected when I am preparing to fire.













Some of the magic this visit was happening next door, at Straw's Farm,
where the spring lambs were doing whatever it is they do.

Because my propane-fired kiln is outside, I am often asked how I can fire in the winter. Doesn't the cold prevent the kiln from heating up? Internally I chuckle at these inquiries. The difference betweencomfortable and uncomfortable, for people, is less than 100 degrees, and the first 100 degrees are the easiest for the kiln to achieve. I'm regretting those chuckles now, because, at -5°, the winter cold does in fact make s difference. Not to the ability of the flame to heat the kiln; that's still a negligible effect. The problem is getting enough propane to the burners to burn! Propane's phase shift from liquid to gas is -44°. It's stored as a liquid by keeping it under great pressure. When some of the pressure is relieved by opening the valve, some of the propane turns to gas and escapes out the valve, down the pipe and to the burner, where it (hopefully!) is burned to create heat for the kiln. This phase change - from liquid to gas - is endothermic, meaning it consumes heat energy to happen.

The closer the external temperature is to the liquid-point (there's some chemistry term for that, can't think of it right now) of propane, the less pressure is required to keep it in a liquid state. The tank loses pressure as it empties anyway, and the endothermic phase shift makes the tank even colder than the air around it.

If the air around the tank is -9°, as it was when I got up this morning, I would still be able to grill a steak using my propane tanks. The firing, however, takes hours - 11 hours even if everything goes perfectly. The tank is getting colder and losing pressure the whole time. The burners wouldn't stop burning, but it would be as if I were turning the valves down, down, down.

I might be able to finish the firing... I do have completely full tanks, which matters (pressure!). But it's possible that I will attempt to do the firing and just burn a bunch of propane and stall out before I reach temp.

Also - not that this affects my plans! - loading in the sub-zero suh-hu-huhuhucks. The my hands hurt, the wadding keeps freezing, the wax on the bottoms is brittle and flakes off.

So, firing this week is a big ol' nope. Instead, let's enjoy some Sonny Boy Williamson!

Yesterday's firing was textbook; like ya see in the pictures, if anybody made movies about firing. Almost perfectly even, light to moderate reduction the whole way...I'm almost worried that it was too perfect, that the demons who torment potters will have a nasty surprise inside for me.

But that's silly...right?

I'll find out on Wednesday.

...firing a raku on the hottest night of the year.
At least I hope it will turn out that was the hottest night! I kind of feel cheated: May and June are two of the three nicest months in Maine - the third being September - with temperate days and cool nights. This year, and last year, we had 45° and rain right up until we were catapulted into the 90s. Temps in the 90s are not supposed to happen in Maine! Or at least not for more than a few days each summer, in late July or early August. It plays hob - HOB, I TELL YOU - with the gardening season. I'm hoping things will mellow out in the next few days.


Nevertheless, the raku must go on! Well - technically that's not true, I've cancelled raku for all kinds of reasons, often weather-related, once mostly because I was just not feeling it.

It was sweltering, but we got some amazing results. I had all beginners! But they listened well and followed instructions, and we got some of the nicest copper lustre results I've seen in a while. The students have since taken theirs home, but mine are still at Portland Pottery, for people to check out. .

If you are thinking about doing a raku firing or taking a workshop, let me share a couple of things with you to make it a better experience:
The first couple are safety related:

1. Wear cotton clothing! It's hard for cotton to catch fire. Not impossible, but a stray ember is unlikely to light it. Polyester, nylon, rayon? All bad choices.
2. Wear closed-toed shoes! You may be called upon to stomp out flames. You want to be able to answer the call without harming your tootsies.
3. If your hair reaches your shoulders, tie it back.
4. If you are manning a post-firing reduction chamber, once the chamber is closed, don't open it for any reason for at least about 6-10 minutes. If you deprive the flame brielfy of oxygen and then suddenly allow an influx, you can get what's called a backdraft, which sounds kind of tame but is in fact a ball of flame, with you in the middle of it. You won't like it. 

These next apply more to workshop situations than private firings. In a small, one-person kiln, some things are easier than in the large kiln, so these suggestions don't apply in those cases. If you are firing your own kiln, handlling your own tongs, put in any size pieces you want, for example! These are more like workshop etiquette:

1. Don't bring teeny tiny things. No beads, no buttons, no earrings. I once had a workshop participant bring like 30 1-inch pots. It wasn't her fault, nobody told her! But it was a misery getting those out of the kiln before they cooled too much too get any nice metallic colors, without getting burned. (Mostly my hands. The fireman's jacket protects the rest of me, but the gloves can only do so much as I reach repeatedly into the glowing kiln. So, yeah. Don't do that. 
2. Don't bring anything you wouldn't want to lift with three foot tongs and drop into a pile of wood chips right next to other clay pieces. No huge things, nothing delicate or with long fragile appendages. Raku is hard on pieces, both the thermal shock & just the thumping around that's going to happen putting them in the reduction chambers and into the water. 
3. Make sure you have used a claybody that is appropriate for raku. There's a pretty broad range of bodies that will work, and some that aren't great but will probably work for some pieces. The best ones are groggy stoneware, or porcelain, or bodies made for raku. 
4. As noted above, raku is a risky process for the ware. Sometimes stuff breaks. Don't do it if losing a piece is going to break your heart. 

I'll post some photos of the ware and a fabulous raku glaze recipe here next week.