Wednesday, December 2, 2009

photos from a pity party

Well I had a little pity party with Brandon Phillips this morning! At least I'm not sick like he is, but I think we are in about the same frame of mind this morning. Everyone go over to his blog and give him some virtual hugs!!! So here is the damage assessment. Some of you mentioned some possible causes. First, yes I did wash the bisque, every piece, very well. the clay is Phoenix from Highwater. I fired to ^05, ramped up 150 degrees per hour, very slow, for 10 hours. However, at 1200 the kiln started climbing fast and shot up 400 degrees before I knew it. I slowed it back down, but maybe this did something. Almost everything was Temmoku, sieved well. I have decided to work with one or two glazes, get them dialed in, before I try others in this kiln. I used this same glaze in the last firing with beautiful results, not one pin hole. I had ^10 flat, top and middle, some reduction, not a lot, but ok. I looked back at my firing log and the last time I fired this temmoku I had ^11 down, so maybe it wasn't hot enough? But I thought temmoku could go to 9 or 10. Not everything had pinholes. The mugs had one or two, a couple of bowls had none, all fired in the same bisque. Luckily, I don't trust this kiln yet, and I am not putting a lot in it at one time, so I didn't lose a huge amount of stuff, but enough to piss me off. It's still $$ lost that I don't really have.
here is some of the pinholing, temmoku is the most difficult thing to photograph!
can you see the pinholes in this mug? Am I being picky, would you sell this?
This was a test, and of course had no pinholes and came out beautifully. Why wouldn't it? This is temmoku with a reduced amount of red iron oxide.Quite nice, with my first practice at slip trailing, which I probably won't do again, but it was fun to try. Sorry Blaine for the rip off, but I had no idea what to draw so I just went with your demo :) The tray was made from a hump mold I made in a class demo, it works pretty well.
This is the only little bowl that survived, I like it with the Raku, sort of solves my functional pottery issues with this raku glaze
This was another test, the bowl was screwed up inside, so I dipped it in temmoku and then in a Nuka test I have. Looks like it needs more heat, but it's a bit funky. So that's it. Thanks to all for your comments. As soon as I unloaded this pile of shit the first thing I wanted to do was talk with my blogger friends. Who else would understand better than all of you!!! Thanks for being out there, wherever you are, hugs to all!!!!! and by the way, beer and chocolate solve all my problems, ya'll :)


Judy Shreve said...

It's interesting that your last firing was a little hotter & no pinholes - someone told me that pinholes can sometimes heal over with a soak - which in essence is going one cone hotter.

Another thing I forgot to ask when you trim - do you smooth your clay back down with a rubber rib? Sometimes trimming a groggy clay will leave a roughness that encourages outgassing or pinholes.

I think you are smart to just work on a couple of glazes & figure them out. Small steps. I keep wondering when I'll just get it - & quit having to learn new stuff all the time! Why do we love working in clay? Maybe it's because of all these challenges. And chocolate heals all my ills as well! said...

I know what you mean Judy, I just said that today, when does the learning stop, I looked at my firing log today and it looks like one of my notebooks from High School. I do smooth my trimmed pots but the Phoenix isn't very groggy. I think it may have something to do with the bisque going up so fast at the end. I would try and re fire them if they didn't have exploded shards in them!

ang said...

yeh i do a 30min easy soak hold the top temp to finish off the firing in the elect. kiln to fend off the pinholes
and the gas i open up all dampers and clean up for about an hour at the end..
it could be the speedy section that you talked about ..
also i sponge off all my bisque ware before glazing to remove any kiln dust... hope you sort it trace, take your time..

Sister Creek Potter said...

I know nothing on my own experience but today I was at a little glaze deom and was told that pinholes may occur from too fast drying of the applied glaze. The solution was to add gum to the glaze (CMC). The slower drying was said to prevent pinholing IF not caused by escaping gas that does not have enough time to heal over (as 'ang' suggested). Good luck--I do know how frustrating this is. Gay

Blaine M. Avery said...

I like the slip trailed turtle!!! It might be the clay switch the clay body that my two cents?

Kim Hines said...

hi tracey, i feel for you. i recently lost a whole load and almost my kiln due to an over fire. going for ^6, the kiln guy said i hit about ^13 -ouch!

anyway, i haven't worked in ^10 reduction so not sure if this would work, but could you maybe use a dremel to grind the bits of the post out of the surface of the bowls, just till you hit the glaze, and then re-fire?? i used to do this in ^04 all the time and worked like a charm (i wasn't too careful back then lol). might not be 1st quality but maybe good for 2nds? just a thought... good luck! Kim said...

Hi Gay, the glaze was actually drying pretty slowly, so I don't think that was it, Blaine glad you liked the turtle, the glaze is really nice on it, I'll have to keep it for a memento of your workshop :)
Oh Kim, ouch indeed! I did try the dremel, but at ^10 the shards were in there pretty solid, couldn't budge them. oh well........thanks all for the words of advise! If I figure it out, I'll let you know. I think it had to be the end of the firing on the bisque when the temp went up so fast. I checked my firing log and the bisque before the successful temmoku was slow slow as advised from Mark and Meredith at Whynot. said...

Ang, I did a ending 30 minute soak on the successful firing at a hotter temp than this last one that may also have something to do with the pinholes....God, why isn't anything simple!!!!!

Laura said...

girl, were you really up at 4am?? I do think the temoku and the blue raku look great together, and very nice turtle plate!! good luck sorting out the complicated and mysterious kiln/temp/glaze issues. I have no wisdom to impart on that front. good luck on Sat. xoxo

Trish said...

Tracey...well craptastic!!! that is the 'pits'... It must be the week of weird firings across the miles. I fire to cone 6/7, so don't know much about higher. I agree with Judy about the soak helping smooth the melt out.
Good luck with the recoveries.
Trish from 'now cold/wintery' Alberta :-)