Roberta12

I have a full shelf on the bottom, but use half shelves after that.  I fire a lot of plates and platters, I have had no problems spanning the half shelves.  I appreciate the flexibility with the half shelves.  As well as being able to easily heft them into the kiln.
I use kiln washed cookies for my porcelain.

Even at $100/pound, say you put 30 grams of glaze on a mug and 3 grams of that is tin it's only 66 cent a mug in tin.
I don't let it put me off using it, I like tin  

You have to use 4 posts under the full shelf so they line up with the half shelf posts. This is the problem. With 4 posts there's a good chance the shelf will rock, leaving one post not making contact and putting a lot of stress on the shelf there, resulting in cracking or warping. I really don't understand using a full shelf on the bottom and the rest half, but it's the way many people think it should be done. There's no benefit to having a full shelf on the bottom.

I have a full shelf on the bottom, but use half shelves after that.  I fire a lot of plates and platters, I have had no problems spanning the half shelves.  I appreciate the flexibility with the half shelves.  As well as being able to easily heft them into the kiln.
I use kiln washed cookies for my porcelain.

Tacoma Clay Art Center carries Corelite shelves. You probably already know this but if you order anything from Seattle Pottery Supply I would strongly suggest asking for the current price, not prices shown on their website.

Ouch! I've found that most of the time prices for raw materials are less expensive in the US but my local place has tin listed at $59.10 (Canadian dollars) for 500 grams which puts it at $43 US dollars for just over a pound. 

Yes, you just have to make sure they're sitting evenly. A waster slab across the joint is also helpful.

I prefer half shelves. More flexibility, easier loading, and half shelves tend to last longer. Posting gets awkward when using both full and half, because you end up having to use 4 posts on a  full shelf and they don't always sit evenly, which puts a lot of stress on them.

I rarely need to level the base of a pot, if the pot has a foot ring (most om mine do) I don't try and level the entire base. I trim as usual then when I have the foot ring trimmed to width I trim a bevel into both the inside and outside of it then just use a loop tool to cut off the tip of it. Since it's just a very small amount of clay getting cut off it's easy to hold the tool level to do this.

 

Trimming feet for almost everything, hence I leave clay for that at the bottom, also, wiring off, quite often, leaves a step.
I'll wire off when the top portion is stiff enough to handle, then set the pot on a plaster bat to dry out the bottom.
So, once set up to trim, after the first pass, I'm using the needle tool to establish level (height) and round (width) foot ring.
The needle tool goes right in - it doesn't follow the contour of the work.

Well Pres, that sounds slick!  I think I need a visual!

In addition, rims are usually compacted more in throwing. 

I wonder if it was because it was porcelain that I had the issue. less porous and absorptive. I may have to revisit this situation.  

I have had  some success with mixing a little of my clear base glaze into the underglaze colors.
Also, I’m not sure why one would bisque to a higher temperature when that makes the ware less porous and absorptive   Wouldn’t that tend to make the underglazes bond less well to the clay?

did a  big birdbath in the 70s without glaze.  molded the shape on a piece of fabric stretched over a large, 22 or so inches diameter trash can and held in place with several rubber bungee cords.   rolled out a slab 3/8 to 1/2 inch thick and draped it into the fabric while keeping an eye on the bungee cords and avoiding their slipping down the can.  
came out great, plain 112 plus 112 with lots of red iron oxide to make fake wood supports running through the bowl so smaller birds could use them while drinking.  adjusting the cords allowed the bowl to be shallow enough, 2 to 3  inches, for birds to bathe safely.  glaze is too slippery so i did not use it.  threw a separate  large diameter, flared base about 9 inches tall so the ratio of support was enough to prevent tipping over.
sadly, i was not home when the first frost was predicted.  calling my son to ask him to take it inside did not work.  teenager.

@HenryBurlingame  I live in Colorado and  all I have are accolades for Rob Battey.  He has been my "phone" support for 11 years.  When I call or email with panicked questions, he is there and walks me through everything.    I have 1000 firings on my L&L e23t.  It is a great piece of equipment.  A friend of mine has a Cone Art. Again, a great piece of equipment.  As far as I am concerned, the only drawback with a cone art kiln would be the extra element in the bottom.  It's another element to  replace.  
Roberta

@HenryBurlingame  I live in Colorado and  all I have are accolades for Rob Battey.  He has been my "phone" support for 11 years.  When I call or email with panicked questions, he is there and walks me through everything.    I have 1000 firings on my L&L e23t.  It is a great piece of equipment.  A friend of mine has a Cone Art. Again, a great piece of equipment.  As far as I am concerned, the only drawback with a cone art kiln would be the extra element in the bottom.  It's another element to  replace.  
Roberta

You can't go wrong with either one. They are very similar in construction aside from the element holders. Both have zone control, neither one requires element pins. The L&L will be easier to replace bricks, but if you're careful with your kiln you won't need to do that.
There's very little reason to fire to cone 10 in an electric kiln unless you're doing crystalline work. Glazes won't turn out the same as if fired in a gas kiln to cone 10, because most cone 10 glazes are made to fire in reduction. If your'e firing in oxidation, cone 6 is a much smarter way to go. Your kiln will last longer, your elements will last longer, and your firing and maintenance costs will be much lower. If you are going to do crystalline work, then the L&L JH model is the way to go. It's rated to cone 12, is built with K26 bricks, and has type S thermocouples, so it can handle the high temps much better.
Shop around for best pricing. 'Packages' aren't always the best deal. Since you're in Washington, I highly recommend calling Rob Battey at Northwest Potter's Supply if you go with the L&L. He's a great guy and has been providing tech support for L&L for years.

@Roberta12Good answer!!

this is cool!  I had not heard of spangles before.  Florian explains nicely.

Or mica perhaps?

I figured out what was causing this, but wanted to allow for a lot of firings to make sure. It turns out that inside the digital controller that I added, the 'wire-end' of the compression terminal on one of the internal wires was a bit too close to the controller's metal housing. I disassembled the controller (which was bought in one preassembled piece), and found signs of arcing. I put a good bend into the terminal, put everything back together, and have had no problems now over many, many firings.

I just realized that I never came back to reply, and it's super irritating when people do that...
Anyways, I tried working faster and stirring more vigorously, and the plaster set up as usual. Success!
I didn't know that faster stirring made for stronger plaster, so I'll get out the jiffy mixer next time. (I learned to mix plaster in a community college class, so we might have been stirring by hand because it was more practical for a group of people than taking turns with a jiffy mixer.)
Thanks, all, I really appreciate the advice.

I did a little research and found that old plaster sets up fast,  a bag that is 4 to 6 months may to old.   And the big hard lumps are from adding to much plaster at one time and not getting well mixed.  The plastic bag might have made it harder to mix,  I use a pretty old bucket and pop off the cured plaster and wash it.   When it gets to the point it won't clean up anymore I find another old bucket.     To make sure my water is really cold I put ice cubes in my water,  when they are melted I am ready to mix.    I never slake my plaster slab plaster,  I haven't had trouble with bubbles.  I set the edge of the bucket in the bottom of the mold and pour it out letting the plaster fill in the corners.  Sometimes I need two buckets of plaster so I find a friend to help mix a second bucket  while I empty the first one.   I made two to four piece molds for a while,  and used the finger flip method on ornate pieces to eliminate bubbles.   I was train dental lab technician and spent the first couple of years making plaster molds off the forms the dentist sent us.  You should be alright on you next slab,  just one of those days.    Denice

The only thing I am out of is Lithium,  so I don't mix any glaze that contains Lithium.   One of these days they are going to figure out how to make a battery easier and cheaper without using Lithium.     Denice