Roberta12

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

I have been spending a lot of time and energy replacing my Gerstley Borate glazes. The new ones are coming along, but they just don’t have the same glow and magic. I am trying to push the limits of “how much boron can I get away with?”
The good news is that switching to Fabi Talc in place of Texas Talc has been seamless. 

Many commercial underglazes just don't hold up at cone 10. They start to flux out and that causes them to behave poorly when you put a glaze over them. If you're just looking for black or blue, you'd probably be better off making your own underglaze or slip. If you do want to use commercial underglazes, each color will need to be tested to see how it holds up and cone 10 and with your clear glaze.

Laguna now sells a flameware body so you can get a 25# at Laguna/Aftosa location in Fl

Damn @neilestrick!!!
Best low fire work I’ve seen in a long time. So good I could eat it.
To @Biglou13, bisque anything will tolerate that kind of abuse better than a clay close to maturity. Lots of grog, kyanite, or even spodumene (gotten a bit expensive lately) will help. Unglazed flameware sounds better than any other clay body, but I haven’t tried that.
It can be done in the studio, ordinary clay products that handle the extreme temperature swings of cooking, but that’s far from saying it should be. I’ve made several earthenware pots that survive the stovetop, experimenting with clay formulations and bisque temperatures. Though I used them regularly, the maintenance was unforgiving (mold will not be denied if given a habitat to grow), and sooner or later they will fall apart despite all best practices. You didn’t bring this up, but I would never try to sell such a thing. Too complicated. 
Pottery used for cooking is largely disposable, in places it’s actually used. Manufacturers like Le Creuset and Wiliams-Sonoma create ceramic ware that’s functional in a contemporary kitchen, but they are carefully engineered first world conveniences. If people can afford to use metal they do. 
I’ll confess, I’ve never had better beans than those I cooked in clay pots. I don’t want to discourage anybody, I just think they should know what they’re in for. 

@Biglou13I started seriously making sourdough bread 6 weeks ago. Sooooo much fun.  I took a class and learned what I had been doing wrong!  I use cast iron skillets, aka dutch oven.  I would recommend that as well.  

Test the element resistance, it's the best way to know for sure. But with 15 minutes longer and 75 firings they're probably still good. Resistance per section for 240V1P should be about 14.45 ohms.

At 800 degrees, the glaze particles have not begun to sinter, they are just a little toasty. Fix the kiln and refire.

As much of the density or mass in a firing comes from the shelves themselves it's often helpful to put the taller pots on the bottom shelf, shorter pots and more shelves in the middle of the kiln and tall again on the top shelf. (assuming it has with just one thermocouple or is a manual kiln)