Friday, March 18, 2011

The loading and glazing routine here

Kathy at Kings Creek Pottery in Schoharie County, NY, asked in a comment yesterday about my kiln-loading routine. So I thought I'd post it on the blog rather than in a comment. Might help someone else out.
My Olympic DD-17 natural gas reduction kiln is pretty small, about 17 cf of stacking space. So I can make that many pots in a few days, drying and biscuit-firing permitting. Each stack usually amounts to about 100 pots, depending on their size.
I have fired three times now on new silicon carbide shelves, which I like a lot because of their light weight and the fact that they shed glaze drips pretty easily. Not the great amount of grinding and kiln wash that was necessary the first seven or eight years on the cordierite shelves.
I learned one of my loading tricks several years ago from Toff Milway, a terrific salt glaze potter at Conderton in the Cotswolds of England. ( We were visiting Toff and he told me that he dry-stacks every load of pots. That is, he takes his unglazed pots and loads them onto the shelves, building up the stack until he's satisfied with the full load. What that does for me is show me first that I've got enough pots to fill the kiln and second it helps me understand how my shelves have to be stacked and what pots can fit where. This is all a little vague as I read it, but it works for me.
Once I've done that, and cleared the big table in my studio of debris, I unstack the kiln, pulling down the front shelves (usually still with pots on them ... I know, it's dicey) and placing them on the table in the order that they come down. I have about enough space to place the front shelves on the table, leaving the back shelves still in place.
Then I take all the pots out of the bottom two shelves, glaze them and put them back in, starting with the pots in the rear and working forward. I usually put shorter pots on the outside, climbing upward in size to the pots at the center of the two lower shelves, trying not to put pots into any kind of flame shadow. That holds true all around the bottom shelves, since those are at the same level (about 9 inches in height). The bottom two shelves always take the longest to glaze. I always feel like I've made real progress when I can begin glazing the upper shelves.
At that point, I've managed to free up a bit of space on the table, so I usually bring down the back shelves and set them out in order. I'll glaze the pots on the back shelves right to the top of the stack, then begin again on the lower shelves. I try to stagger the shelves front to back to allow for full penetration of fire through the stack.
Using cordierite shelves, to which my stoneware pots often stuck during a firing, I adopted refractory wadding from wood-firing and now I still wad all my pots. I hated the chipping footrings that often resulted from firing on those shelves, even if they were kiln-washed. Wadding adds a step, but I've fired woodkilns so much that I'm used to it. The fired wads do get underfoot after an unloading, though.
That's how I do it, Kathy. It seems to work pretty well for me, but as you know, everyone does things a bit differently.
The photos above are pots that will be in a joint show called "The Potter and the Painter," with Dara Pannebaker, at the Stove Factory Gallery in Charlestown, MA, part of Boston, in late April.


Kings Creek Pottery said...

Hollis, This is fantastic! Thank you so much for explaining your process. Loading a gas kiln is so different than the electric~ many more factors to consider. I like your method because space is maximize as you think ahead. I love the pottery blogs, such a supportive community! I am learning SO much :)
Thanks again!

Hollis Engley said...

You're welcome, Kathy. Hope it helps.

Michèle Hastings said...

that's a really interesting method and does sound efficient. our kiln is (unfortunately) too far from the studio to implement that method. we most always end up with a board full of extra pots that have to wait for the next firing.

Hollis Engley said...

Yes, I understand that problem, Meesh. I'd prefer the kiln be out on its own, but this is what I've got right now. There are advantages, such as ease in loading, but firing in mid-summer, when indoor temps reach 130F, is not my favorite thing.

FetishGhost said...

Those shinos are dreamy Hollis. mmmmmmm
I sat in on a long winded discussion regarding the use of wadding, a lot of people seem fine with thinking that kiln wash is the end-all solution to everything... I don't enjoy chipped feet either. I'm become a habitual wadder too.

Hollis Engley said...

Yes, the wadding eliminates any possible problems like that. Most of them, anyway. I've known people to imply that you don't know how to mix kiln wash if it isn't working for you ... and maybe that's true. But for me it's easier to go with something that works for me and get on with making pots.

lukefitch13 said...

Stunning pots Hollis, really interesting to hear your process too

Hollis Engley said...

Thanks, Luke.