Mixing Kiln Shelves?

[Marko]

I just got a full round shelf, just one, these things are expensive. But now I have another problem; how, can I, should I,or is the best way to stack Halves and one Full Round (22") shelf in my electric kiln to maximize my firing. All answers are welcome. Even the ones that roll eyes, but have a humorous edge to em, nuk nuk nuk. 

[neilestrick]

Ideally, all the post should align vertically so the weight is carried by the posts. You do not want a post sitting in the shelf without a support underneath it or you run the risk of cracking the shelf, or causing it to warp. Also, each shelf should only have 3 posts holding it up, so that it can't rock. This gets tricky when you try to mix full and half shelves. To get posts to line up vertically, the full shelf has to have 4 posts. You'll find that it won't always rest equally on all 4 posts, which means that that side of the full shelf is not supported underneath. It's not ideal, but you have to do it if you want to mix them. You can also use clay wads under the full shelf to get it sitting even on all the posts. You'll need to dip the wads in kiln wash or Alumina to keep them from sticking to the posts. Or you can cut the full shelf in half. It's pretty easy to do with a circular saw with a masonry blade. If you only have one full shelf, make it the bottom shelf. Put it on 1/2" posts or kiln shelf shards, and use clay wads to get it sitting even.

[Mark C.]

Neil said it best use the full as the bottom shelve-My full shelve is the bottom and always stays in.

[MatthewV]

Half shelves are only somewhat expensive (~$20). Hopefully affordable enough to get enough to fill the kiln properly. Unless you live in a place that is hard to ship to. This cost will come back to you in being able to finish more work in a load.

 

Unless you plan on making platters that fill a full shelf, I personally recommend only getting one full shelf for the bottom. Half shelves use more posts but allow flexibility and better use of the space. They are also easier to load and handle.

[oldlady]

my half shelves always go in the top of the kiln.  they are usually posted so that at least 2 of the posts rest above the stack of posts from the bottom of the kiln.  since the weight is negligible, i do not worry about the third one.   sometimes because the last of the whole shelves contain taller things, i do not worry about the small stuff on the half shelf and put it where it fits.

 

i have always disliked half shelves in general.  whole shelves are much easier.  one half shelf is usually all i would use in a firing and only in a situation like i described.

[Marko]

Ideally, all the post should align vertically so the weight is carried by the posts. You do not want a post sitting in the shelf without a support underneath it or you run the risk of cracking the shelf, or causing it to warp. Also, each shelf should only have 3 posts holding it up, so that it can't rock. This gets tricky when you try to mix full and half shelves. To get posts to line up vertically, the full shelf has to have 4 posts. You'll find that it won't always rest equally on all 4 posts, which means that that side of the full shelf is not supported underneath. It's not ideal, but you have to do it if you want to mix them. You can also use clay wads under the full shelf to get it sitting even on all the posts. You'll need to dip the wads in kiln wash or Alumina to keep them from sticking to the posts. Or you can cut the full shelf in half. It's pretty easy to do with a circular saw with a masonry blade. If you only have one full shelf, make it the bottom shelf. Put it on 1/2" posts or kiln shelf shards, and use clay wads to get it sitting even.

Thanks Neil. I am starting to make large plates, so I bought a full shelf just for that, but didn't think about what to do with the rest of the kiln, hehe. Can I use many full selves if I go with 4 posts? 

[Marko]

Half shelves are only somewhat expensive (~$20). Hopefully affordable enough to get enough to fill the kiln properly. Unless you live in a place that is hard to ship to. This cost will come back to you in being able to finish more work in a load.

 

Unless you plan on making platters that fill a full shelf, I personally recommend only getting one full shelf for the bottom. Half shelves use more posts but allow flexibility and better use of the space. They are also easier to load and handle.

I have plenty of half shelves, but I read somewhere that I should not use two half shelves to make one full shelf. I was wanting to make large plates, platters and large shallow party serving bowls. 

[Marko]

my half shelves always go in the top of the kiln.  they are usually posted so that at least 2 of the posts rest above the stack of posts from the bottom of the kiln.  since the weight is negligible, i do not worry about the third one.   sometimes because the last of the whole shelves contain taller things, i do not worry about the small stuff on the half shelf and put it where it fits.

 

i have always disliked half shelves in general.  whole shelves are much easier.  one half shelf is usually all i would use in a firing and only in a situation like i described.

Do you ever put two half shelves together to fire a large bottom piece?

[Marko]

Neil said it best use the full as the bottom shelve-My full shelve is the bottom and always stays in.

 

Neil said it best use the full as the bottom shelve-My full shelve is the bottom and always stays in.

Do you lay it on the kiln floor and the build up with fulls and halfs? 

[Mark C.]

I never span a shelve (like two half together) with a platter.

You could buy another full shelve or make the foot only 12 inches and put 1/2 shelve away from wall on top if you get that  idea?

a 18 inch platter can have an 11 inch foot so it fits on a 1/2 shelve

[Marko]

Oh, ok. I get it. That would also mean I would need as much full shelves. Thanks mucho. Thanks Mark.

[Mark C.]

You can bisque them laying sideways(depending on the clay body) as well on the edge-so only need the shelve in the glaze fire

[Pugaboo]

I too have started doing large plates and some platters and only had a couple whole shelves and mostly halves. DON'T fire a large flat piece spanning two shelf halves even if you put the halves snug up against each other. I fire cone 6 little loafers and tried this early on and got a taco shaped plate.

 

I need to do some dinnerware sets and have found I can fit a service for 4 made up of 5 piece place settings in my little 18x23 BUT ... I had mostly half shelves. I bought myself enough whole shelves so I can fire 4 large plates and 1 platter. I use the halves for everything else. I have been starting with the whole shelves at the bottom. I use 4 posts so that when I get to the half shelves I can switch to supporting each half at 3 points using the 4 posts, where the shelves meet each half gets half the post for support. I make sure the posts all line up one on top of the other all the way up for stability. I haven't had an issue with warped shelves but then most of my whole shelves are new so that might be an issue as they get older.

 

I do have a lot of posts in a lot of sizes (2-10 inch tall) since my kiln is so small. I don't want any wasted space because I only have a 6 inch post left when I need 4 inches, I even have and use quite frequently little 1/2 inch posts that I place on top of other posts when something is just a hair too tall for the size I have. I also use posts to place something up slightly above another piece on a shelf if I need to to make it fit. Loading a kiln is like a 3 dimensional puzzle.

 

Oh and I tumble stack my bisque and can get an easy 3 loads of glaze from 1 bisque load, unless there are a lot of underglaze pieces which can't be tumble stacked then it's 2 loads of glaze not 3.

 

T

[MatthewV]

Pieces just need to have their entire foot on one shelf. Many of my large bowls eat into the airspace of the other side.

 

Another efficiency tip: make leaves or other small things to fill the empty spaces.

[Marko]

Pieces just need to have their entire foot on one shelf. Many of my large bowls eat into the airspace of the other side.

 

Another efficiency tip: make leaves or other small things to fill the empty spaces.

Thanks Matthew. I like your website. I bet your classes are a lot of fun and informative. It looks like a big place. Do you rent or own it? I wish you much success in the years ahead. I hope to do this someday. I like teaching. It gives you something to smile about. 

[Marko]

I too have started doing large plates and some platters and only had a couple whole shelves and mostly halves. DON'T fire a large flat piece spanning two shelf halves even if you put the halves snug up against each other. I fire cone 6 little loafers and tried this early on and got a taco shaped plate.

 

I need to do some dinnerware sets and have found I can fit a service for 4 made up of 5 piece place settings in my little 18x23 BUT ... I had mostly half shelves. I bought myself enough whole shelves so I can fire 4 large plates and 1 platter. I use the halves for everything else. I have been starting with the whole shelves at the bottom. I use 4 posts so that when I get to the half shelves I can switch to supporting each half at 3 points using the 4 posts, where the shelves meet each half gets half the post for support. I make sure the posts all line up one on top of the other all the way up for stability. I haven't had an issue with warped shelves but then most of my whole shelves are new so that might be an issue as they get older.

 

I do have a lot of posts in a lot of sizes (2-10 inch tall) since my kiln is so small. I don't want any wasted space because I only have a 6 inch post left when I need 4 inches, I even have and use quite frequently little 1/2 inch posts that I place on top of other posts when something is just a hair too tall for the size I have. I also use posts to place something up slightly above another piece on a shelf if I need to to make it fit. Loading a kiln is like a 3 dimensional puzzle.

 

Oh and I tumble stack my bisque and can get an easy 3 loads of glaze from 1 bisque load, unless there are a lot of underglaze pieces which can't be tumble stacked then it's 2 loads of glaze not 3.

 

T

Thanks Pugaboo, I appreciate all the info. I now feel confident enough to try things. But I'm not too clear what, Tumble Stacking, is. 

[Marko]

You can bisque them laying sideways(depending on the clay body) as well on the edge-so only need the shelve in the glaze fire

Mark, I would be afraid of standing a plate on edge. Can any piece be laid on it's side? I use Aardvark Bee Mix 5 and when it runs out Laguna Bee Mix 5. Thanks for your help, as always. 

[MatthewV]

Tumble stacking is loading a kiln with only a minimum of use of shelves (if at all). In a bisque firing it happens just by loading stuff on top of other work. In a glaze firings (most commonly seen in Anagama firings), pieces are stacked against each other with wadding between them. The wadding leaves a mark which is effectively a design feature of the pieces.

 

--

I am renting the space but have the aspirations to own in the future. It is spacious with 1000 sq ft of very useful working space. I took the best parts of the studios I had worked in as much as possible and built everything "right the first time".

[Mark C.]

Mark the platters I used to bisque on edge where slightly gorged porcelain . It was a cone 10 special body I had laguna make  it for me by the ton its is Daves porcelain with grog-super fine grog. I cannot say about cone 5 b-mix-I You just have to try one-all part of learning the limits. You will find the limits and thats always good info

My guess it will work I just laid the platters on the edge leaning against the kiln wall.Remember I usually bisque in gas kilns but have done 100's of electric bisques but it not a 1st choice for me.

I learned it from another potter working in porcelain . I have found trying what folks think is impossible sometimes works great- but also some times its a bust.I know the limits and they are not what you may think.

try one and see-just go slow as larger forms need slower temps rises.

[Marko]

Tumble stacking is loading a kiln with only a minimum of use of shelves (if at all). In a bisque firing it happens just by loading stuff on top of other work. In a glaze firings (most commonly seen in Anagama firings), pieces are stacked against each other with wadding between them. The wadding leaves a mark which is effectively a design feature of the pieces.

 

--

I am renting the space but have the aspirations to own in the future. It is spacious with 1000 sq ft of very useful working space. I took the best parts of the studios I had worked in as much as possible and built everything "right the first time".

Thanks again. I assume you have to stack from heavy or biggest to smallest. Is they a loss percentage? 

[Marko]

Mark the platters I used to bisque on edge where slightly gorged porcelain . It was a cone 10 special body I had laguna make  it for me by the ton its is Daves porcelain with grog-super fine grog. I cannot say about cone 5 b-mix-I You just have to try one-all part of learning the limits. You will find the limits and thats always good info

My guess it will work I just laid the platters on the edge leaning against the kiln wall.Remember I usually bisque in gas kilns but have done 100's of electric bisques but it not a 1st choice for me.

I learned it from another potter working in porcelain . I have found trying what folks think is impossible sometimes works great- but also some times its a bust.I know the limits and they are not what you may think.

try one and see-just go slow as larger forms need slower temps rises.

Thanks Mark. I will try this in a small kiln first. 

[Pugaboo]

Marlo,

 

When I tumble stack a load of bisque I only use 2 shelves, the bottom and 1 more. For bisque things can touch so I load each shelf with as much as I can. Plates, mugs, Spoonrests, bowls go face to face, bottom to bottom with handfuls of small items inside,mstacked several high this way.

 

I think Mark C is the king of tumbling here, if you do a search in tumble stacking he has posted images of what his kiln looks like when he does. I am not nearly as radical as he is but doing my version of it my bisque loads got way cheaper to do since I am fitting 3 times the work in there.

 

T

[Mark C.]

Mark see my post on tumble stacking from a few years ago.

[Pres]

I do mix shelves a bit. I have also done some very stupid(to others) that worked out well for me. All of that said, I usually use full shelves in the bottom layers of the kiln, and because my bottom is covered with two 1/2 shelves, I use six posts for the full. Do I get warpage-no. I have also had loads where chalices sat with plates and I really needed to maximize space. I spiraled the shelves around using shelve pieces and short stilts to keep everything level.This allowed 4 plates in a 360 go around, that was about eight inches in height used. 3 times around fired 12, with still room for 20 chalices and some smaller pieces. Yes it worked, but it was a bugger to load, but filled the need at the time.

 Over the years I have not warped a full or a 1/2 even when I over slept and probably hit ^8-that only left a kiln full of bloated pots.

 

 

best

,Pres. 

[Mark C.]

Pres I also have overslept-its two alarms always since that time.