Pres

you might want to contact Marcia Selsor about the way she handles the large slabs she uses in raku.  not that you want to do raku, but the way she prepares the slab when she does the horses that are a part of her work.   look at her website and here in albums to see the results.

Minimize bending the clay while rolling it out or when moving it from the roller to the drying boards. Dry between sheets of newspaper sandwiched between drywall boards or cement board untill completely dry. Change boards when they are damp by changing the top board, flipping the sandwich, and then changing the other board which is now on top. Allow to completely dry before firing. Fire on edge. Yes, fire on edge.

Also, pound the clay out into a slab until it is close to the thickness you need, then finish off by rolling. The less rolling you can do the better. Fire it on silica sand or on a waster slab. Firing on edge may or may not work depending on the type of clay you're using, especially in the cone 5 firing. For porcelain or other bodies that fuse pretty tight it's likely to warp.

On the left, 600g (~1.3 lbs) mug.
A normal/medium mug for me, 350g, however, as the large and extra-large ones, people pick them up, 600g is now "medium" size.
The turquoise plastic tumbler is handy as a "rounder" - the taper fits most mugs, and the shape is, strangely ideal.

I was told that the beautiful Chinese pots were very heavy,  the potters were more interested in the shape and design than the weight.    Denice

@Kelly in AK, I used to be the same, thinner was the mantra, especially in front of students. However, my old self would have gasped at the weight of the floor vases I have made for my wife and some others, but they do not tip over very easily and support long strands and branches without a problem.
 
 
best,
Pres

@Kelly in AK, I used to be the same, thinner was the mantra, especially in front of students. However, my old self would have gasped at the weight of the floor vases I have made for my wife and some others, but they do not tip over very easily and support long strands and branches without a problem.
 
 
best,
Pres

@Kelly in AK, I used to be the same, thinner was the mantra, especially in front of students. However, my old self would have gasped at the weight of the floor vases I have made for my wife and some others, but they do not tip over very easily and support long strands and branches without a problem.
 
 
best,
Pres

This guy is 2-1/2 pounds, so I suppose it started with around three pounds of clay. It feels about right. No “ballast” around the bottom. I have to say, I put some real effort into throwing eggshell thin for a long time, and like to do that in demos for beginners, to show them what’s possible, but better too thick than too thin is my vibe now. Balance. 

It's a scam. I get these emails all the time about kiln purchases and they have a specific freight carrier, etc, etc. They'll probably want to use a stolen credit card to pay for it or something like that.

20 oz mug, 1 lb  (base isn't as narrow as it looks in the picture)

3 1/2 pounds got me this "Little Brown Jug"... 

My wedging table is covered with heavy canvas purchased years ago for that purpose. However I now have a plywood top that fits over the canvas that I wedge on. . . less dust, just as easy to wedge on once you get used to it.
 
best,
Pres

My wedging table is covered with heavy canvas purchased years ago for that purpose. However I now have a plywood top that fits over the canvas that I wedge on. . . less dust, just as easy to wedge on once you get used to it.
 
best,
Pres

Would love to hear how it did in your test!

Hi Carol, welcome to the Forum!
By strange torque, I wonder if what you are experiencing is the clay sliding on the bat?
Of the several bat materials I've tried, the black plastic ones seem to offer the weakest grip for the clay.
If that's it, going a bit wider on the centered part, and going easy might help?
As the bats got scratched, well, the shiny wore off, that seemed to help too.

An additional thought on Rhodes: he wrote several books, Clay and Glazes may be the most well known but he also wrote "Stoneware and Porcelain" and "Pottery Forms".
Our high school library had all three books and I poured over them endlessly as an impassioned wheel thrower. What made Pottery Forms so unique was that Rhodes often showed pottery shapes in profile. Meaning...he would cut the pot in half to show the wall thickness. That really sent home the message that a well thrown pot has an even thickness clay wall. (To prevent cracking, mostly, and warping.) I don't think too many other books had this element? 
What the profile shots also did was send home the message that crafting a good pot involves two processes: throwing the pot and trimming the pot.
 

Looking at your pictures I agree with others that the form was thrown too thick, and needed more aggressive thinning to make up for the difference.  I Love throwing large bowls, and other forms for the kitchen, and these require a major amount of wedging of the clay, Mastering the clay on the wheel(coning up and down), and aggressive pressure from the base up into the cylinder walls. Throwing a bowl starts with a rounded interior when opening up, and most of the pressure during pulling is from the outside with more of a flat fingers on the interior keeping the curve of the base into the cylinder then when sufficient pulls have thinned the base the walls are shaped from the inside. My favorite tool for this is a large wooden spoon with the handle cut off and the edges rounded out where the handle had been attached. Whether a dish(flat interior bottom) or bowl (rounded interior bottom) the trimming is important to make certain there are no areas in the base that are thicker than normal fo any thrown piece.
All this IMHO, meant to be helpful, not critical.
best,
Pres

Looking at your pictures I agree with others that the form was thrown too thick, and needed more aggressive thinning to make up for the difference.  I Love throwing large bowls, and other forms for the kitchen, and these require a major amount of wedging of the clay, Mastering the clay on the wheel(coning up and down), and aggressive pressure from the base up into the cylinder walls. Throwing a bowl starts with a rounded interior when opening up, and most of the pressure during pulling is from the outside with more of a flat fingers on the interior keeping the curve of the base into the cylinder then when sufficient pulls have thinned the base the walls are shaped from the inside. My favorite tool for this is a large wooden spoon with the handle cut off and the edges rounded out where the handle had been attached. Whether a dish(flat interior bottom) or bowl (rounded interior bottom) the trimming is important to make certain there are no areas in the base that are thicker than normal fo any thrown piece.
All this IMHO, meant to be helpful, not critical.
best,
Pres

Thank you for the photos. I believe you made the pots too thick. The outside profile vs. the inside shape shows it, to me, clearly. If the bowl is in fact 20” wide, the foot must be well over an inch thick in some areas. 
There are many variables (relative humidity, clay body, temperature of candle, etc.), an eight hour candle ought to have taken care of most of them, but honestly it’s just too thick and blew up. Water did that. 

Lots of great discussion here, but we still don't know what the blowouts look like, where they were on the piece, etc. OP has abandoned us. Personally, I've never considered compression to be the cause for blowouts. They are typically caused by foreign bodies in the clay or moisture. I don't see why compression, platelets alignment, etc, would cause a section to violently separate from the piece.

Hi folks, sorry things are late for this weeks QotW, but I have been self quarantined for much of the Christmas holiday, things are negative now.
I know that some of you out there make your own tools, and some feel it is time consuming using the time saved with purchased items to make more pots. However, there are some of you that make your own tools, whether it be ribs, throwing sticks, dies or other things. I do wonder though how many of you make your own brushes? In the past (college days) I had access to deer hair, and some other animal hairs as I hunted and knew folks that trapped and had some other types of hair. I began experimenting with rolling the ends in paraffin, and wiring to a stick. Simple brushes, but interesting how course hair and fine hair would give me different effects, They were fun for in-glaze brush work with accents of dark stains or glazes. Their biggest attraction was the uncontrollability as compared to a commercial brush. Yet after a while, it seemed there was little time to make new, and they did not hold up well especially when dealing with some course glazes or stains. 
QotW: Have you ever experimented with making you own brushes? Please elaborate on how you did it.
 
best,
Pres 

I rely heavily on a deer tail brush as part of my glazing process. They last a long time, but I taught myself how to make them just to make sure I would always have one. I made a video for anyone who wants to learn how, it’s free on youtube.
 

Mea's details are spot on
I use JB weld epoxy and  a  fine nylon line for hair wraps and heavier line to make my hang loops but its really just minor details-I also drill a hole thru center of bamboo to pull  string with the hairs up and make a loop to hang brush then glue the holes shut.
I have about 4-5 kinds of bamboo (I tend to harvet black bamboo for handles) The timber bamboo in photo gets 30+ high and gets water from sink clay  settling tubs then on to bamboo.
Here's a bunch hanging next to sink waiting for glaze day-I do tend to make them larger than hers -larger handles and more skunk hairs
My glazing is lots of loose brush work under glazes like rutile so these brushes get a workout nearly every week or two.
Thanks Mea for posting the you tube. I never had  a mentor on making these just winged it but that process is the same. I really got into it in the  late 80s and 90s. These where made then.
 

Hi folks, sorry things are late for this weeks QotW, but I have been self quarantined for much of the Christmas holiday, things are negative now.
I know that some of you out there make your own tools, and some feel it is time consuming using the time saved with purchased items to make more pots. However, there are some of you that make your own tools, whether it be ribs, throwing sticks, dies or other things. I do wonder though how many of you make your own brushes? In the past (college days) I had access to deer hair, and some other animal hairs as I hunted and knew folks that trapped and had some other types of hair. I began experimenting with rolling the ends in paraffin, and wiring to a stick. Simple brushes, but interesting how course hair and fine hair would give me different effects, They were fun for in-glaze brush work with accents of dark stains or glazes. Their biggest attraction was the uncontrollability as compared to a commercial brush. Yet after a while, it seemed there was little time to make new, and they did not hold up well especially when dealing with some course glazes or stains. 
QotW: Have you ever experimented with making you own brushes? Please elaborate on how you did it.
 
best,
Pres