Tuesday, June 9, 2009

More cone 6 Reduction

I finished up my second cone 6 reduction firing this afternoon. For the non-potters out there, the above picture is of the cones at the end of the firing. The cones measure temperature and are the indicators we use to fire the kiln.

The firing took slightly longer than I had expected. The plan was to fire a little faster. I'm still troubled by how to keep the kiln climbing while gradually backing off on the reduction. I have forced air burners which I can control two different ways. Add to that the gas and the damper and I have too many variables to screw with.

I was reading Val Cushing's notes in which he describes how he prefers to fire using only the damper. He doesn't change the gas or air settings past going into body reduction. I might try that next time since I'm having trouble keeping the kiln climbing at more than 100-120 F per hour post-body reduction. I'm afraid I'm clearing the atmosphere more than I want to just to get the temperature up.

I'm also going to take some measurements of my chimney opening. I have a suspicion that Ian Craven may have made the opening smaller by adding a couple of bricks. When I follow Bailey's instructions my air flow does not seem to be adequate. The top gets around 200-300 F hotter than the bottom until I put it in body reduction. Then it pretty much evens out.

I guess there is a lot to learn, but I'm not going to dwell on all the numbers too much. The Studio Tour is in a few days so there is plenty of other work to do around here. The kids are out of school and there are playgrounds to visit and rocks to turn over. I was up at 4:15 this morning and there is a sack to hit.

This is the only picture I have of this basket. I had some customers stop by yesterday who saw this one and bought it. I only had it out of the kiln the previous evening and wasn't ready to say goodbye. Does anyone else do that: visit with the pots before selling them?

Sunday, June 7, 2009

Cone 6 reduction Results

I candled the kiln overnight Friday and started a slow climb Saturday morning since the leveling strips and cone packs were still wet. The early climb was a little uneven top to bottom, but a damper adjustment fixed that. I started reduction around 11:00 and cone 6 was flat and I shut the kiln off at 3:15. I think my climb was too slow (only 130-160 F per hour), but it seemed any adjustment I made to speed things along resulted in uneven heat. I have to look over my firing notes and decide what to change for Wednesday's firing.

This morning at 8:00, the interior temp had dropped to around 500 F so we were able to unload by dinnertime. With one notable exception, the results were dazzling. The tile on the left was fired at John's last week. The tile on the right is from the same exact cup of glaze but fired in my kiln. I loved the glaze at John's and made a 5000 gram batch. It is pretty uninteresting and in fact looks like watery baby shit.
The yellow pot below bears little resemblance to the test tile from John's, but I am in love with this glaze. I tested my cone 10 glazes and several look exactly the same at cone 6. Yippee! They can do double duty. I still need practice with the spray gun, and I might try to refire some of the pieces where the glaze is too thin. All in all I think the firing went really well. Cone 6 reduction kicks ass!

Friday, June 5, 2009

Pilots Lit!

Brenda (one of my college studio-mates) has come to visit, glaze some pots and fire the kiln with me. I've spent the past several days pouring over all the test tiles from John's class and decided that the next logical move was to mix up 4 more base glazes to test. Is there a support group for John Britt glaze junkies? Too much more of this and I might need professional help.

This firing is a group effort in every sense. I ran out of titanium and was able to borrow some from Sarah. Brenda brought several cone 6 pieces and Tria brought by some cups. Marian is coming up tomorrow to cheer me on while I fire and maybe test out a new Sangria recipe. Jay helped out by taking apart the pilots, cleaning and painting them. Oooooh shiny!

Everything has really fallen into place. I was only able to decide on 3 glazes to mix up and I was concerned about glazing a full load with only 3 colors. However as I loaded the kiln with all the work, I quickly realized that I had made more than enough for one load.
In fact, I am certain I have enough for another load. I'm going to fire a second cone 6 on Wednesday. I figure that I'll be able to unload the kiln Friday in time for the TRAC Studio Tour. How's that for waiting until the last minute? The great thing is that I'll be able to enjoy my new test tiles and make some new colors for the second firing.

Tuesday, June 2, 2009

Shameless Plug

These are the two pots I have at the TRAC Gallery in Spruce Pine. The white basket is from my cone 10 load last fall and the heart bowl is cone 6 oxidation. Both glazes are in need of improvement. I think it was Shane Mickey who mentioned at a Clay Club meeting how eager we potters are to leave behind the pots from our last firings. I tend to agree with him.

Armed with my new-found cone 6 reduction knowledge and a healthy amount of chutzpah (not to mention the constructive criticism I received at a critique), I can't wait to see my new work with new glazes.

I'm glaze firing on Saturday June 6. Come on down! I'm #17 on the map http://www.toeriverarts.org/tourmap.shtml