Things are in an intermission right now. I am still waiting for the vase to cool down, so it seems like a good time to go through my 'educated guess' of an art project.
Basically, I haven't done a smoke firing in a jury rigged set up at home before; I have always used a big gas kiln and had other people around to help baby sit the process. Oh, and I have always started with bisque fired ceramics, not greenware pieces. But from asking around, it seems like I should be able to do a smoke fire, from greenware, in a pit of my choice. So....
If I slowly heat up a fully dried piece of greenware (in a low fire or designed for raku type clay.... just something with high grog) and expose it to a smoldering fire of organic material, then I should have a finished, bisque, smoke fired piece when it cools down.
I'm feeling pretty good about things. I know that the clay is very dry and I am experienced enough with burning things and a charcoal grill (I have dubious hobbies) that I think I can control temperature and rate of combustion. Yeah, and I am really sorry about my crummy kettle. The finish is a bit *hem* worn and then it is covered with pollen. I would have cleaned it first, but it didn't seem quite so embarrassing when I was taking the picture. Please ignore my shame!
I should point out that because I am using the same kettle that I use for cooking, I am going to be extra paranoid about what materials I am going to be using. The ceramic piece is going to be surrounded by organic matter that will slowly burn and 'char' the surface. Remember that combustion is a chemical process. Some things will be transformed but some things may just volatilize and linger in the lining of the kettle, contaminating later cook outs. Transformation problems will happen with many things, but most importantly, anything with salt. NaCl gives you beautiful blushing on your ceramics, but when it breaks down you will have chlorine gas, which is highly corrosive, damaging metals, finishes, and killing you dead. So no salt, unless you are doing this with a professional. And then it is temping to throw on lawn clippings and weeds/leafs but remember that there are potentially harmful compounds in many of these. You just don't want a residue of something nasty if you are using your kettle. If you are using a pit in the ground or a large metal container, than no worries (just don't breath in the smoke/fumes unless you know there is nothing bad in there).
So..... I made myself a bundle out of aluminum foil with holes punched in it (so oxygen could get in... you need oxygen for combustion). The vase went into this bundle, surrounded by coffee grounds, coffee filters, egg shells, and newspaper. Let's call it, breakfast: deconstructed and then lit on fire. Basically, I scavenged from things headed to the compost pile.
I put this bundle on top of the charcoal chimney to slowly heat up the vase/bundle while I got the briquettes going.
Once the briquettes were alight, I emptied the chimney into the kettle and placed the bundle on top.
This is where I did a bit of a re-think on my game plan. The bundle was plenty hot, but the contents were not catching fire. So I decided to open things up a bit. Since the vase was very hot, I didn't have to worry about temperature shock and subsequent breakage from open flame.
And so the plan changed. I opened the bundle, lit the top on fire, then put on the lid (with vents open), to let things slowly smolder.
Now a quick fast forward:
I checked on my bundle this morning. It was still crazy hot and the contents of my bundle really didn't burn very well. So I opened the bundle up more and re-lit it, then put the lid back on. I did sneak a peak at the vase while I was pushing around some of the cinders and it looks good! So I am hoping that it should cool down by tomorrow morning, I can remove it, and then see what I can do to 'finish' the vase.
And I am sorry for all the 'un-pretty' pictures.... I promise the next post will be extra spastic on the color to make up for things.
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