Pres

I use two clay bodies, one for cone 6 soda firing and the other is a local clay that fires at cone 03.
The cone 6 body is Laguna B-mix 5. After trying various clays I found it responds well to soda as well as hot and cool spots in my kiln. It seems easy to throw for me and is pretty tolerant when my craftsmanship isn’t perfect. The downside is it’s expensive compared to other white stonewares.
The local clay is something I’ve played with for many years and gotten to know. It isn’t tolerant in any way! I add 1-1/2% Veegum to it, the biggest monetary expense. It cracks, slumps in hot spots, and is left porous in cool spots. I have to be completely on my game to make it work, which is part of its charm. I haven’t tried to calculate the cost, I’m afraid it would be too discouraging. 

Some cracks never heal and some get bigger. Learning which are fixable takes experience . Yours is only going to get worse and if it where mine I would toss it and make a new one.I have used bisque fix for many successful repairs but knowing its limits will take time for anyone to learn

@Russ, I understand your concerns about the aggressiveness of a wood firing, and agree that not many shelf clays would handle that firing.. I live not far from a wood firer who is quite old now, but I am pretty certain in the day he did much of his own clays. I believe now that his clays are manufactured by SC. which gives his name away. 
On another part of your posting, if you look through the last few years of posts about clay there are several times that material suppliers have disappeared or changed mines or some other thing that has disrupted the quality of the clay manufacturers just as it has yours.
 
best,
Pres 

@Sara KelleyFiring the pot the second time vitrified the clay body a little more, and caused more shrinkage of the clay thus enlarging the crack. When I have had issues with cracks of this sort in student pottery, I would have the student enlarge the crack by scraping out the area with a pointed tool like a can opener. Then clean it out well leaving no dust dampen the area and force the repair agent deep into the crack, and not have much over the clay surface around the crack by scraping the surface smooth. Fire to the normal temperature which in your case was 04. You have to realize the your clay body and your repair material probably have different shrinkage rates due to the firings - very difficult to repair after bisque.
 
best,
Pres

That type of crack is likely to continue to get worse, especially in the glaze firing. Sometimes it's best to just move on and make another one.

I use this 

As for mould release agent.....  Nothing required for slip casting.  Nothing should be required for press moulding, but talc can be used in porous, non-plaster moulds, or WD40 in non-porous non-plaster moulds.
The only other time you would need to use mould release is when creating the mould.  Different master materials require different mould release (and some need none), and you need a soapy release between different sections of plaster, so they don't stick together.
Try your local library or the online auction site for a copy of the Clay Lovers Guide to Making Molds.  It has a list of release agents for diffferent materials.
 

@GeniumI added a prefix to your post title. If you would edit the post and change the title to something other than your name, you would get more traffic on the post, and the search engines would be able to pick up the post when someone in the future needs help with the same topic.
 
Welcome to the forum, hope you find your answers!
 
best,
Pres

I pour outside, finger swipe, spray through stencils. . . weeds, found objects. . . .lace, artificial branches etc, all over textured surfaces that break the glaze even more.
 
best,
Pres

Hi  folks, this last week @Pyewackette posted a question in the pool. Even though I think we have covered this sometime this year, it never hurts to approach from a different angle.
@Pyewackette posted:
QoW: What clay body or bodies do you work with and what do you like about it/them? What is the impetus for working with one or multiple clay bodies?  Corollary:  do you make your own clay, and why
My thoughts on this are pretty simple. I use two clays for the last several years, a white clay SC630 that is quite nice to throw and takes my glazes that have used for years quite well. I also use a SC Hazelnut Brown to give me a different set of colors when working. No change in glazes as they look different but darker on the Hazelnut. As far as mixing my own clay. . . not enough space, too much dust, too much mess, more equipment, and too much work! i'll order mine premixed and ready to go!
 
best,
Pres
 

It looks like your cone 6 firing got to about cone 7. Your 05 bisque firing was just slightly over fired, probably not enough to worry about. It's not uncommon for them to fire a little hot at the cone 6 range for some reason. I have to program my kiln to 2190F for cone 6 instead of 2232F. You have several options to dial it in:
1. Set a thermocouple offset. I wouldn't do this, though, because the bisque firing was pretty close to where it needs to be.
2. Set a cone offset for cone 6.
3. Do a custom program, setting the peak temp to whatever it needs to  be at to be accurate. I would start with it about 20-30 degrees below cone 6 (2232F). You can copy the firing schedule in your manual for most of the firing. Just be sure to set the last 200F degrees to a rate of 108F/hr.

A bisque to cone 04 will be fine. You don't need to do the long 'first firing' program you did when you first got the kiln.

Hi  folks, this last week @Pyewackette posted a question in the pool. Even though I think we have covered this sometime this year, it never hurts to approach from a different angle.
@Pyewackette posted:
QoW: What clay body or bodies do you work with and what do you like about it/them? What is the impetus for working with one or multiple clay bodies?  Corollary:  do you make your own clay, and why
My thoughts on this are pretty simple. I use two clays for the last several years, a white clay SC630 that is quite nice to throw and takes my glazes that have used for years quite well. I also use a SC Hazelnut Brown to give me a different set of colors when working. No change in glazes as they look different but darker on the Hazelnut. As far as mixing my own clay. . . not enough space, too much dust, too much mess, more equipment, and too much work! i'll order mine premixed and ready to go!
 
best,
Pres
 

I pour outside, finger swipe, spray through stencils. . . weeds, found objects. . . .lace, artificial branches etc, all over textured surfaces that break the glaze even more.
 
best,
Pres

I pour outside, finger swipe, spray through stencils. . . weeds, found objects. . . .lace, artificial branches etc, all over textured surfaces that break the glaze even more.
 
best,
Pres

Pour inside, spray outside.  I will say spraying is a labor of love. Takes a lot longer to spray a pot than dip it, and it can be difficult to get consistent results. Dipping is definitely a better method. I need to embrace it more.

You’ve ruled out your wedging surface, so that leaves a problem with the clay. If it’s fresh out of the bag, it could be that the batch you have is new clay, and it may resolve in a week or 2. If it doesn’t resolve, contact the manufacturer and see if there are any new materials being used (talc is a recent culprit). It may be a qc issue on their end. 
Frozen clay is a possible issue as well. Some clay bodies benefit from being frozen and thawed, others need to be slurry reclaimed before they can be used again. 
That leads to the last idea I have: If you’re wedging reclaim, are you making sure the fine particles from your throwing slop is going in the bucket with the trimmings and mushed pieces? 
 

Thought this was a good time (seeing it is American Thanksgiving), to put out a thank you to the potters on this forum who give selflessly of their knowledge and time to help other potters.  Together you have built a great resource and you are very much appreciated.  
 

With the gas kilns it’s all me, and that’s been a long slow learning curve. It started with “don’t blow yourself up.”
My experience with electric kilns is a different. I count on electricians. However…I learned, as many do, electricians in general are unfamiliar with kilns. If you find one who is into kilns, they’re a gem! I’ve learned enough to do a lot work myself, but I’m not yet confident to flip any switches till a pro checks it over.
Except the thermocouple. I don’t need a pro for that. 

Hi Pot, Welcome to the Forum!
Good question. I'll circle back and post links to further reading later...
Meanwhile, I work in a single car garage space (previous Studio was also a single garage space!), which does have ventilation options, however, much of the year is rather hot, else chilly. 
I try to keep after the floor with a wet mop - an actual commercial bucket, wringer and mop. Having the floor accessible helps there. The mop is handy for cleaning off shoes/sandals as well - don't track it around!
In general, any dry clay - bits, pieces, splatter, slip - can easily become dust. Hence, I'm looking to keep dry clay to a minimum, wipe off the work surfaces, tools, wheel. No waving cloth about that has dry clay embedded in (rags, clothing, the dreaded canvas, ugh).
The only dry clay I want to see is greenware awaiting first fire (on shelves, out of the way and protected), and clay to be reclaimed (stored away).
I'm seeing the wedging station being a dust source, also trimming at the wheel.
There are strategies for minimizing those dusts, tbc.
The typical dust generators I see are:
  stepping on clay that's on the floor
  dry clay, slip, glaze, etc. that's disturbed and flies into the air
  airborne dust that's settled, then re-launched, repeat, repeat...
It's nice to have ventilation, however, I try not to roll up the door or open the window if there's any dust to be kicked up by moving air - clean up time.
Best case, my Studio is relatively dust free when I start a session, then I've cleaned up at the end for next time.

More reading:
Very paranoid about Silicosis - Studio Operations and Making Work - Ceramic Arts Daily Community
Silica Dust Exposure - Studio Operations and Making Work - Ceramic Arts Daily Community
Can air purifiers remove silica dust from my Ceramic Studio - Studio Operations and Making Work - Ceramic Arts Daily Community|
Dust Collection For Small Studio - Clay and Glaze Chemistry - Ceramic Arts Daily Community
Toxicity (digitalfire.com)
Dedicated Studio shoes/sandals, no tracking clay into the house!
For if/when clay gets on clothes, have a few clean sets handy in the Studio.
Change rags when there's any dry clay on thar, bag or drown in water, along with dusty clothing! ...else, wet that rag.
Wipe down clay smear/bits inside the clay bags with a big ol' sponge, then spray a mist of water in thar before closing up the bag.
Dry clay on plastic sheeting/bags -> instant dust!
Handle the dried out empty clay bags outside, away from the Studio (clean inside and out, save for reclaim!).
Some forum regulars are using air filtration systems, also centralized vacuums (where the exhaust is routed outside/away).
My overhead kiln vent doubles as a glaze mixing station fan.
I'm handling the glaze material outside, away from the Studio door - repacking from the sacks and bags into lidded containers - then hosing the area down later.
Find a P100 (or equivalent) dust mask/respirator that fits you well and wear it when doing dust things.
Check/clean surfaces regularly. Note where dust accumulates, and how much - that's why I believe wedging and trimming are what generates dust in my Studio.
How else can one assess the dusty-ness of the working space?
Heh, I've posed this question several times over the last five years or so...

All these points are so good! Thank you for taking the time and sharing it with us all.

Hi folks, I have seen a LOT of kilns having problems of late on the forum. Many folks asking for help/advice on whether a kiln is worth fixing, or if they should buy a certain questionable kiln. Makes me wonder how many people know enough about kilns to repair them by their self or if they will hire a tech for their problems. I can remember back when I first started firing an old Amaco kiln that there were all sorts of problems with the coils falling down, and bricks breaking because I jammed a shelf against it. Then we got a new kiln, and had an electrician come in to wire it to the wall, and set it up. He knew wiring, but didn't know much about kilns. . . relied on me, which by then I had gotten a little more savvy about what I fired. When the first element burned out a few years later, I reported it, and waited and waited, ordered new ones, and waited. Then I had an afternoon where there was a pep rally and teachers were in-servicing. I asked for the time, and an hour after everyone left I had replaced the elements. Next week the electrician arrived checking on the kiln came to me asking what was wrong. I explained everything and asked him to check over the work. He pulled the box checked the leads ran a few tests with a multimeter, came back and said it was all good. Said there was a kiln up at the Jr high that was having problems and asked if I would go up and look at it with him. . .said sure!
SOooooo ! QotW: Do you repair your kiln, or hire an electrician/specialist to do the job?
best,
Pres

Hi folks, I have seen a LOT of kilns having problems of late on the forum. Many folks asking for help/advice on whether a kiln is worth fixing, or if they should buy a certain questionable kiln. Makes me wonder how many people know enough about kilns to repair them by their self or if they will hire a tech for their problems. I can remember back when I first started firing an old Amaco kiln that there were all sorts of problems with the coils falling down, and bricks breaking because I jammed a shelf against it. Then we got a new kiln, and had an electrician come in to wire it to the wall, and set it up. He knew wiring, but didn't know much about kilns. . . relied on me, which by then I had gotten a little more savvy about what I fired. When the first element burned out a few years later, I reported it, and waited and waited, ordered new ones, and waited. Then I had an afternoon where there was a pep rally and teachers were in-servicing. I asked for the time, and an hour after everyone left I had replaced the elements. Next week the electrician arrived checking on the kiln came to me asking what was wrong. I explained everything and asked him to check over the work. He pulled the box checked the leads ran a few tests with a multimeter, came back and said it was all good. Said there was a kiln up at the Jr high that was having problems and asked if I would go up and look at it with him. . .said sure!
SOooooo ! QotW: Do you repair your kiln, or hire an electrician/specialist to do the job?
best,
Pres

Always done my own work-from electrics to gas. Once 50 years ago I melted my 60 amp service and called a friend (an electrician at the time) who tught me how to fix it. He became a electrical contractor and I used to work for him now and then never looked back on hiring anyone for electrical work. I call for code updates now and then . Gas kilns same deal build them and fire them-up to about 12-14 under my belt now. Worked as a plumber with a plumber contractor back a the in the 80s never needed one to run pipes . Being a potter for me means knowing a lot about manicanical things. I learned them for those in the trades-same with home building -framing and roofing. Potter for  me means the whole of an all-arounder. 

Ceiling fan is a cheap and great idea.   I worked with a portraiture sculpture group for ten years.  We  made turntables out of formica sink cutouts and ball bearing kits for lazy susans.   I have a large heavy duty one that I put together.  It will easily hold and turn a couple of hundred pounds of clay.   Denice