Saturday, August 23, 2008

Kiln repairs

We've gotten word that our studio will remain where it is for the time being and we started to work on fixing the place up a little. My task was fixing one of our three kilns. An ancient Cress cone 6 electric beast that has only been able to reach bisque temps for awhile now. This is the first time I've tried to repair an electric kiln. It was kind of cool.

I assumed that the issue would be the rheostats or the elements. I bought new elements and figured I'd replace those and if that didn't work I'd replace the rheostats.

We have three kilns in our studio, all lined up against one wall. The other two kilns were bisque firing. And it was hot out. It took me about 2 minutes to start sweating. I took off the bracket that the rheostats and kiln sitter are mounted on.and bang - there was the problem. One of the jumper wires had broken. I ran down to Seattle Pottery Supply and got a replacement. Less than $5 of replacement parts.

Since I had already bought the new elements I decided to install them anyway. I got the first element in fairly quickly and easily. Until I was feeding it into the last few inches and realized that the new element was about 10 inches too long. I made it fit but it wasn't easy. It was enough to convince me that I didn't really need to install the other 3 elements.

I test fired the kiln to a couple hundred degrees and everything seemed great.

Since that kiln is back up I am going to do a couple glaze loads soon. I had been putting it off as the kilns that were running didn't reach cone 6, only cone 4-5.

Saturday, August 16, 2008

Pictures of tea dust bowl

Jeff took some pictures of the porcelain bowl with the temmoku that developed the tea dust crystals.









Wednesday, August 13, 2008

A few random notes

I ran across some recipes for cone 6 oil spot glazes. Now if you're like me you're thinking "cone 6 oil spot? Un-possible". My understanding of oil spots is that the spots are caused by the iron basically boiling. A reaction that I thought didn't happen until cone 7 at the lowest. So I am looking at these glazes thinking they're crap. Then I start noticing the names are the same as some oil spots of John Britt. John is the man when it comes to oil spot glazes. I decided to dig a little and sent John an email. I call him John because I addressed the email to Mr. Britt and he replied "No Mr. Britt bullshit". So John tells me that the recipes I stumbled upon were actually his. He had provided them to the person who had posted them. He also stated that yeah, these could maybe work at cone 6.

So who knew; real oil spot glazes are possible at cone 6. I am ovewhelmed with current tests so I am not planning any tests on these. Write me and I can provide the exact recipes.

I have been working on a cone 6 chun/jun glaze. I have done a few tests with an ash nuka base. I got one that melts well at cone 6 and I think will work. I mixed up 4 more tests with several additives; rutile, iron, copper, cobalt. I'll post results.

Wednesday, August 6, 2008

I win!

The success rate for beginning potters like myself can be low. For every good pot I make dozens of losers. Bad forms, misbehaving glazes, kiln mishaps, whatever.

Tonight I won one.

I have a stable temmoku glaze, Val's Temmoku Gold. It is a beautiful black with golden tea dust crystals on stoneware. On porcelain it looks like a traditional temmoku, rich brown. I also have a rutile wash that flows nicely and leaves wonderful colors when applied over the temmoku. It's a nice glaze combination.

A few weeks ago I threw a large porcelain bowl, about 7 inches high and 16 inches wide at the mouth. I intentionally left a large foot on when I threw it. I trimmed and cut the large foot down to 4 feet large enough that you can see under the bowl when it sits on the table.

I sprayed the temmoku on the bowl, applied the rutile wash to the lip of the bowl as well as the top of all the feet. Popped it into the kiln yesterday and pulled it out tonight.

Stunning. No question the best finished pot I have made to date. I have never had tea dust crystals on porcelain before, only on stoneware. The entire interior of the bowl has a evenly distributed layer of the tea dust crystals throughout. The rutile wash ranges in color from white to yellow to purple. And flowing slightly inside the bowl as well as outside.

I am not posting pictures yet because my camera sucks and I am taking this one to my buddy Jeff whose hobby is photography.

Tuesday, August 5, 2008

YAY!!

I was all gloom and doom over the kiln malfunction. I was certain that all the pots and probably all the shelves in the kiln were ruined. Not the case. The kiln even though it was on high for over 24 hours never reached peak temp. All the pots are fine, all the shelves are fine. I always use witness cones and my cone 5 witness cone is straight as an arrow. The glazes are not even partially melted. I will re-fire these bad boys in one of the other kilns this week.

Whew....

Monday, August 4, 2008

Why pottery is freakin' difficult

I have thrown a lot of pots over the last 18 months. Many hundreds. I am sure it's not nearly as many as people who pot full time or those who have been doing it for longer. In that span I have thrown maybe 20 pots that I really liked. After ruining most of those pots by putting unpredictable glazes on pots I actually liked I started saving the pots I liked until I was happy with my glazes AND I got a spray gun. Finally I thought, finally I can finish these pots, the pots I like. The pots I want on my mantle.

I sprayed three of these really nice pots this past weekend. Two in temmoku with the new super cool rutile wash. One with the iron red with a barnard slip/wood ash glaze. I popped them in the kiln yesterday about noon.

Well there are a lot of moving parts in pottery. A lot of variables. One such variable is the kiln. Our studio has three kilns. All fairly old. All use kiln sitters.

For some reason the kiln didn't shut off. It should have shut off about midnight last night. Instead when someone got to the studio about 4 in the afternoon the kiln was going full tilt. I don't know if the kiln didn't get to temp or if something held the kiln sitter lever, or what. The kiln got shut off and will cool over night (it was hot as hell at 8pm when I showed up) and I will survey the damage tomorrow morning. I expect a complete loss.
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And thus I lose 3 more pots. Pots that I liked but by the time I finish the process something goes sideways.

Friday, August 1, 2008

Slow period

I've hit a spot where I am not doing a lot of new pots. This is by design. The studio owner where I work is moving to a new studio and I am following her there. The new studio is nearly complete. As such we're winding down all activity at the old studio as we get ready to move.

We don't want to move greenware - so no new pots.

I'd prefer not to move bisqued pots - so I am trying to spend more time glazing pots than testing glazes.

And once we do clear out all the pots we have the fun and exciting task of actually moving all the pottery equipment, kilns, slab roller, wheels, shelves, etc, etc.

All in all it means a lot of work in the studio but not a lot of pottery getting done for the next few weeks.