Sunday, August 15, 2010

Giant Grasshopper

Been getting my firing done in big bites, like a grasshopper does to a leaf. This Eastern Lubber Grasshopper, Romalea guttata, is almost 4 inches long and quite colorful. I thought about chocolate covered grasshoppers; when I saw the armor-like skin, I said to myself, no thanks.

The test fire for my new kiln was a fast 04 as recommended, completed in 7.5 hours, with one coat of kiln wash. It was rather smelly, the oils on the elements burning off. The cones showed the bottom shelf went beyond 04 target. If there's no clay pieces in the load does it fire hotter or cooler? I might get a few more cones like 03 and 05.5 if there is such a cone. Ideally I'd like to shoot for firing my bisque just tiny bit under 04.

I know if the kiln is fired faster it's programmed for a hotter fire from the factory. Perhaps a slow fire wouldn't be as hot. So I programmed in 05 for the bisque because I don't want to go over 04. I think higher than 04 will adversely affect glaze penetration and adhesion. I figure a little under is better than over 04 cone. I've adapted a firing log that Gay, from Sister Creek Pottery, sent me to keep notes about my firings. The notes will be invaluable as I go along, thanks Gay.

I had so many tall vases I had to use one side of the kiln for those. Remember the tall vase I wondered about, well it is too tall to fit in the kiln, unless I use a half inch post on the bottom. I'll check it out when I unload the kiln. I may have to take that one somewhere else to be fired. For a half shelf that's 26 inches across, I've used four posts, do you think I should only use three? If so that would give me more room.

I wanted to make a more even load, but I couldn't figure out any other way to load this one. Let's see, I've got 17 vases, 6 lided boxes, 4 pinch bowls, 2 fern trays, a magic umbrella (ha) covered dish, and a wall vase in this load. I really packed those vases, are they too close? I probably could have squeezed lots of small items on the right side of the kiln, but I didn't have any made. I'll have to remedy that for the future. I'm half an inch from the top on the right hand side, hope that's not too close.

I didn't get any of my plates or platters in this load, I figured if I got all the vases out of the way, then I could do a load of smaller pieces and plates. Actually I have a few more vases and some odd shaped sculptures for another load too. I probably could have put a shelf on the bottom right below the vases for plates, but I don't want plates on the bottom, so I left a bit of room at the top on that side.

Various circumstances beyond my control prevented me from firing my new kiln much till recently, so now I am getting caught up. My plans are for back to back firings for the next week or so. The bisque load was fired yesterday and is almost cool enough to open, firing was 11.57 hours, final temp 1881. Please check back for results, only the cones know for sure. I'll be doing a glaze fire in a jiffy. Comments and suggestions are welcome.


  1. Linda your load looks well done- we split the kiln a lot and I think it fires just fine.
    It must be exciting to be working along!
    and those shrimp!

  2. Hi Meredith, thanks, yes finally, the weather for two weeks was lightening and electrical shutdowns every day, then more car catastrophes, etc. Hope all is well in the kiln, Gary was teasing me saying he didn't hear any very 'loud' noises, then he said someone in the neighborhood was doing target practice.

  3. You don't need the 4th post.Any warp in the shelf will make it rock.3 posts won't rock, Just like a 3 legged stool.

  4. Hi Dennis, thanks ever so much, I thought I saw a few other kilns on blogs with three posts and wondered the reason for that, now that you've explained it to me it sounds scientifically reasonable. I sure don't want any wobbling going on in there especially as tight as I packed some of it. Thanks again.

  5. Linda..the load looks great and some interesting pieces to come from it!..happy for you to have it up and running..and a four inch grasshopper!! good grief!:)
    Cheers, T.

  6. Hi Trish, thanks so much. I am so happy to have this kiln, my mind is racing at the possibilities, the only thing is all the heat it puts in the garage. Optimum would have been to have a separate building, but maybe next place. for now I may spring for a vent which I've heard helps dissipate the heat more quickly. I'll have lots of glazing to do that's for sure.

  7. oooh plenty of room you should see how i pack a bisque!! yep 3's the way to go with your posts, keep them stacked vertically on top of one another it keeps the load of the kiln all in the same place...does that make sense?

  8. Yeah Ang, thanks, I am so used to loading a gas kiln rather than these upright kilns. Now that i think of it they were using four posts or more there, perhaps that wasn't right either, but that's what the teacher wanted. I knew the posts should be under one another. I just thought these shelves were so long across at 26 inches I wondered about three posts, but it all makes sense to me now. I wish I had an apprentiship with another potter and then I would learn so much 'on the job' so to speak, but I'll keep plugging along. I just noticed there are you tube videos on kiln loading, I forgot all about checking those out. thanks again.

  9. Glad to see Ang's post about the tight packing. I was afraid yours was too tight--wondered if they might crack. I usually have a light load to fire so never have the need to put pieces so close.
    Are you using the cone fire mode for both bisque and glaze? I've used the ramp and hold mode for both--makes me feel more in control--which is a joke since I don't have any idea what I am doing or why!!
    Happy for you to be firing your own brand new kiln!

  10. I definitely will be back to hear how your pieces fared. It sounds like a very ambitious undertaking to me. I hope you are having a wonderful day. Blessings...Mary

  11. hey 26" shelf that's sizeable...mine are def smaller than that the clubs are only 16" x 16" but mine would be about 23" x 12" in my gas and all our college ones were quite large and we used the 3 post system.. maybe someone else has the same setup as you..hey what about emily murphy she has a big kiln!! i'm just wondering about shelf thickness and firing speeds and what the shelves can take..

  12. like Ang we pack a very tight bisque load, stacking bowls of the same size on top of each other, rim to rim... smaller pots inside larger pots, beads inside bowls. as for your tall vase... since you don't have a kiln vent you can place it directly on the floor of the kiln. we always load from the floor up.
    good luck with your marathon firings!

  13. Hi Gay, thanks, I did bisque fire on slow which takes two hours to get to 200 and then four hours to get to 1000, but these pieces have been dry for months, if I do another bisque for pots that are just dry I will program it differently with a preheat and then a slow fire till I get over 600.

    For the glaze load, I will program a ramp and hold fire into the kiln, not sure what I will use just yet, will do a bit of research and then decide on that.

    I plan on doing a glaze load next.

    thanks again.

    Hi Mary, thanks, I will open shortly and will post the results of the bisque, then glaze tomorrow and two days for results of firing.

    Hi Ang, thanks, I forgot to mention although these are shelves are octagon, they are those new corelite shelfs which only weight 8 pounds but are supposed to be the latest technology and can go to cone 10 and supposedly very strong, I can carry them under one arm like a breeze, so I think they will be ok. I will check with Emily I remember she got a new L&L and it was huge.

    Hi Michele, thanks, I can place the shelf directly on the kiln bottom? I was thinking that the space at the bottom allows for better air flow? If I could place shelf directly on the bottom then I could fit that tall vase in maybe; it is 16.5 inches tall I think, once it goes through the bisque is should bet a little shorter with shrinkage perhaps. I might call Skutt and see what they say, they are super about giving advice. Thanks again.

  14. we don't even put a shelf on the floor.. the first stack rests directly on it. you can put a shelf on the floor if you want. the shelf protects the floor... if you are doing a bisque firing you don't need to be worried about glaze dripping on the floor of your kiln. if you have a kiln vent then you need to put a shelf on posts for ventilation.

  15. Hi Michele, thanks, oh good point, the bottom wouldn't need protection during a bisque, which would give me the half inch of the post plus the thickness of the shelf - more height for my tall vases or other pieces.


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