Caroline E

@Callie Beller Diesel and @Min Thank you very much for your responses! I have some follow up questions. 
Would the glaze be food safe if it was only applied on the outside? From what I can gather from your response, it is not food safe because it does not properly melt at ^6? I also wanted to ask you about the inclusion of lithium carbonate. I realize lithium carbonate is a toxic material. Does any ingredient labeled "toxic" mean that it can not be included in a food safe glaze? When any material is "toxic", is the concern in the powdered form or the fired form?
Also, can you please expand on your mention of the glaze not including silica and what that does to the nature of the glaze? 
 
Thank you very much 
 
Caroline

I see that there are some cracks running from one lump to another.  I make a lot of tile,   a thicker area next to a thinner slab can cause cracks to form.   She might try removing the clay from the back of the tile in the thick areas  and try to keep the clay a even thickness.  Denice

I don't know how the price compares to Brent but I like my Bailey wheel with the removable splash pan. (bumping this thread, hope to get more replies)

speedballs are Chinese  and so are shimpos now. Pacifica is made by laguna
the best quility wheels are Brents Baileys and Skutts these days .
These will hold resale value best and last a really long time
I have 4 Brents myself now as I sold.a few over the pastr few years

I have 9 Skutt wheels, and love them. Their 1/3hp models can handle just about anything you would want to make.

Do you have any kick wheels in your class room,   I have always thought you could develop good throwing skills on a kick wheel.  I had one until I was 68,  I  was old and have MS and my legs weren't as strong.   Marc found a Brent for me on ebay that was local, it works but I still miss the magic of the kick wheel.       Denice

my personal choice is a Pacifica, bought in late 1970s with only the belts replaced from wear.  i do not count the damage from lightning that required something done with the foot pedal.   i do not use a splash pan and built the table workspace around the wheel.   see my album.
i dislike brent wheels because of their noise.   really awful in a setting where several are being used at once.  did use bailey during an NCECA event in Tampa and liked it's solid construction.   the bailey wins in that two wheel race.  
 
 
 

I put 4 top of the line Baileys in the Ceramics Studio at the HS I taught at over 25 years ago. They are still running well, and I still demonstrate on them from time to time. I still center about twenty # when throwing off the hump, and haven't had any torque lag in any of them. I got them with removable splash pans as @Minsays except for one that is with a fixed pan and drain. It is mostly used for smaller work and trimming even though the motor is the 1hp as all of the others are.
 
best,
Pres

Soldners are fine wheels I just do not think about them since he died. My biggest issue with them is they are so large. My studio is to small for one. The foot pedals are super smooth.

Whichever one you get I’m sure it will be a huge time saver. I would be looking at the ones that can mix as well as vacuum pug, this way you can blend up all the scrap clay from bone dry to wet plus throw in some throwing slop (if your students throw as well as handbuild) churn it up then pug it.
I have a Bailey stainless that I’m very happy with.

For me its a peter Pugger all the way-the 20 VPM is best for classroom size wise
I own a SS VPM20 and an aluminum VPM30
If you are using low fire clay get the Stainless model as it will pit the aluminum model

Those cones are very close in terms of evenness. I wouldn't expect them to be any more even than that. If you're going for a full cone 6 then a 5-10 minute hold ought to do it.

Just a thought.
When I had problem with pin holes in my glaze it was caused by out gassing because my bisque fire was not complete (not hot enough?) When I raised the bisque temp that took care of it. Like I said, just a thought.
Stay safe, Graybeard 

This is what worked for me. I use 12 to 17 minutes based on how dense the load is. I also use an offset like Pres mentioned.

A 15-20 minute hold equals 1 cone hotter, so yet, the hold will increase heat work on the rest of the kiln, too. I would first try loading the middle of the kiln tighter and loading the top looser. Put low mass pieces up top, like wide bowls.  If that doesn't work, I would try firing a cone lower and holding for 15-20 minutes to achieve the next cone.

How many thermocouples in your kiln?  Can you do a thermocouple offset?
As Babs says, 1-2 is not much, maybe try starting with a 5 minute to see what happens.
 
best,
Pres

Hi, is it possible to post a photo of blistered pots and cones? That way folk can better understand the extent of underfiring and length of soak required. A hold of a minute or two won't account for much imo.
 

Thanks so much for the replies! 

In my experience, they may or may not warp back. Doesn't hurt to try, though. Just make sure they're really clean on the bottom so they don't drop stuff onto your pots.

If they are clean flipping will be fine. Just wash the other side. They will slowly warp the other way now.
 

Dear @neilestrick,
Wow! This is GREAT! I very much appreciate you taking the time to send the recipes and test tiles. These look like they will work wonderfully in our studio. I am going to make some tests. 
Again, thanks so much!
Caroline 

Dear @neilestrick,
Wow! This is GREAT! I very much appreciate you taking the time to send the recipes and test tiles. These look like they will work wonderfully in our studio. I am going to make some tests. 
Again, thanks so much!
Caroline 

Dear @Pres, 
Thank you so much for your recommendations! This is all very helpful.  Is the Van Gilder book you are talking about titled, "Wheel Thrown Pottery"? And is the M^6 book you are referring to called, "Mastering Cone 6 Glazes: Improving durability, fit and aesthetics" by, John Hesselberth?
 
Caroline

I use cone 6 glazes at my school, but I buy them already dry mixed. It’s tougher on the budget, but I can barely get everything done as it is so mixing my own for school happens rarely. I have tried Tony Hansen’s 20 x 5 base with both cobalt+black stain and copper carb, both came out great. 
Those are some beautiful looking glazes Neil! I may have to change my ways. 
 

Here are a few glazes that we use in my studio that are very stable and consistent.
Butter is great on top of other glazes, and also looks good alone on brown speckled clay.
Harris Red is a great iron red glaze, tends to be the most red on brown bodies.
Runny White is quite stable on its own, but flows a bit on other glazes. Looks great by itself on speckled brown bodies or on top of just about anything.
S-4 Blue looks a lot like denim, has nice surface variation, and looks good on both white and brown clays, especially on speckled brown.
Spearmint is a nice green with good surface variation.
Nutmeg is a fake shino, which I normally hate, but this one's not bad. Goes lighter as it gets thicker.
*edit- These tiles all show double dips. They are not runny with a single dip.

Nutmeg.pdf Spearmint.pdf S-4 Blue.pdf Runny White.pdf Harris Red.pdf Butter.pdf