yedrow

Tough to answer that question actually. Experience is best, trials are the best way and test tiles with good notes are super important. Experienced potters can tell you a lot of general properties of their glaze, but then again they have acquired the experience. Generalities for a celadon for instance might be darker color with more dramatic breaks and at some point perhaps too thick and it runs or crawls.
Test tiles likely are the best solution, one, two, three dip and so on.
Here is a shot of about 1/5th of the tiles from a Jon Britt workshop. Took him a long time to get this experience. If you go to a workshop you likely can gather some of that experience in on tenth the time or simply exchanging info with other potters often saves a bunch of time.
you can also search https://glazy.org/search?base_type=460&production=false&photo=false Many have pictures and notes on application. All for no charge.
 

Breaking glazes I've found are usually opacified with zinc or tin, but not always and not all of them do it.  I haven't noticed any chemical analysis that predicts it though.

Thanks,
we plan to do something more comprehensive and with more clarity and content. There are so many dependent issues with glazes our hope is to someday incorporate as much gathered knowledge from many sources into a series or chapters if you will, for beginners and maybe intermediates.

I got time to watch that video Bill and it was wonderful!!! Thank's again!

Might be me. It sounds like Stull and I use the Katz worksheet when possible. He provides it free on his website. We actually have a modified version of his sheet with his permission, and provide updates to a handful of  Folks in a small group that does personal  glaze research. Katz course is a Nice course on Claybodies and Glazes. Other than that I have posted a bunch of spreadsheets over time free to anyone who wants them.
Katz Website https://www.ceramicmaterialsworkshop.com/resources.html
over time  we have sought to incorporate as many aids  as practical for beginner potters
here is a link to an early beginner video.  Surface Texture and durability were the intended focus to the intro.
 
If you have a need for any of the sheets, message me. Hope that’s what you were  seeking,
 

Thanks Bill. I don't think it was you, but that looks like some awesome material to go through. Thanks again!
Joel.

Just a tad under 12 on one try, three pulls, with a bottom.
 

  Joel.

I do not recommend a Pacifica, we have one that is just a few months old and already we've had to replace the pedal and it feels like the bearings are going out. I don't like Brent for production use, but I think it would be a great studio wheel, and I like their kick/electrics. I know two production potters who love their VL Whispers, I personally don't like the RKs. I know one master potter who is pleased with his Bailey. I like the Soldner type of wheel, but they're a bit pricey for the average potter. Creative Industries makes cheap wheels, nuff said.
 
I strongly recommend trying the pedal first. Lots of people talk about power, but if you have a weak pedal you are much more limited than if you can't throw a 50# block of clay. I know a 110# woman who can center a 6# chunk of clay as well as I can, and I'm a stout guy. Precision trumps power IMO. However, if you are planning on centering 15 or 20 pounds, you may want to go for a stronger wheel. If on the other hand you are planning on turning out coffee mugs and pie plates, a responsive pedal is top of the list. I can throw on anything, but a touchy pedal, well, it just makes pottery not fun.

I've been using hardiboard for the top of my table for the last few months. It isn't plaster, but it works pretty good.
 
Joel.

Just a tad under 12 on one try, three pulls, with a bottom.
 

  Joel.

I have a life-time supply of river clay from the Red River which was part of the "flood of the century"in 1997.We shovelled bucket after bucket of Albany slip looking clay from the steps of our parliament buildings.
The woman who helped me without complaint I eventually married. She had other fine qualities, but she knew how to handle a shovel.
I have at least 5, 5 gallon pails of slip clay. Unfortunately, people don't buy black pots here, or even brown pots.
TJR.

OCD works when the devil is in the details.
 
I started quite late in this race, so I need to leverage whatever gizmos I can come up with to catch up.

I like challenges. When I was younger I played foosball for money. I got 9.5 inches in two pulls and just a squeak under 12 in three. If I did a few with that purpose in mind I'm certain I could get up around 13" or maybe a little more. I torqued this one about half-way up (trying too hard) and that cost me a little height.
 
http://ceramicartsdaily.org/community/topic/4793-12-inch-club/
 
Thanks for pointing that out, it was fun.
 
Joel.

Great video yedrow- you could probably do the nine inch club in 2 pulls!

I throw four to five days a week at work, and I work at home some as well. It's a pretty tight pace. Throwing bigger stuff uses up a lot of clay. That being said, unlike Neil and others I don't throw anything over 20 pounds and rarely that much. I make production stuff at the pace customers purchase it. Most of what I make is 6 pounds and under. That means lots of mugs and pie plates.
 
Joel.
 
Joel.

I do what should probably be called quasi-production. I don't make only one thing, I make several different items and often three or four different things in a day. I throw around 35 to 40 one pound mugs in an hour, around 18 pie plates in an hour, and around 18 three pound spoon jars in an hour. I throw between 100 and 150 pounds of clay in a day.

I hand make my handles. To do this I roll the clay into a ball, then without changing much of the motion, I roll it into a carrot shape. Then I slap this down to flatten one side and then cut off the tip of the big end. I wet both the mug and the big end and attach the handle. I can do this in about the time a person using an extruder takes, when doing a run of 30 mugs. After 30 mugs the extruder starts getting faster. But, if I'm doing 10 mugs I'm much faster. All total it takes me about 4 minutes to throw, trim, and handle a mug.

Repetition is the trick. On top of that, I'm a form guy. I have no interest at all in a well glazed pot if it doesn't have good form. I follow a simple set of rules I learned from a Ferguson quote, "First learn technical skills, then form, then the kiln/glaze, and finally surface." Most of the work I've seen ignores the first two parts and goes straight to glaze and decoration. But to me, to get the beauty out of a pot, you need the form. Form comes from control and control comes from practice. Just make lots of pots. And, if you can, find a good handle and try to reproduce it. I think I have a good handle, here is a pic. Feel free to give it a shot. Another couple of tips: Good handles come from a good eye for negative space, and let yourself flow, like water. Beauty comes from natural motions in an analog sense, not from digital skips and jumps.
 

 
 
 

I do what should probably be called quasi-production. I don't make only one thing, I make several different items and often three or four different things in a day. I throw around 35 to 40 one pound mugs in an hour, around 18 pie plates in an hour, and around 18 three pound spoon jars in an hour. I throw between 100 and 150 pounds of clay in a day.

I hand make my handles. To do this I roll the clay into a ball, then without changing much of the motion, I roll it into a carrot shape. Then I slap this down to flatten one side and then cut off the tip of the big end. I wet both the mug and the big end and attach the handle. I can do this in about the time a person using an extruder takes, when doing a run of 30 mugs. After 30 mugs the extruder starts getting faster. But, if I'm doing 10 mugs I'm much faster. All total it takes me about 4 minutes to throw, trim, and handle a mug.

Repetition is the trick. On top of that, I'm a form guy. I have no interest at all in a well glazed pot if it doesn't have good form. I follow a simple set of rules I learned from a Ferguson quote, "First learn technical skills, then form, then the kiln/glaze, and finally surface." Most of the work I've seen ignores the first two parts and goes straight to glaze and decoration. But to me, to get the beauty out of a pot, you need the form. Form comes from control and control comes from practice. Just make lots of pots. And, if you can, find a good handle and try to reproduce it. I think I have a good handle, here is a pic. Feel free to give it a shot. Another couple of tips: Good handles come from a good eye for negative space, and let yourself flow, like water. Beauty comes from natural motions in an analog sense, not from digital skips and jumps.
 

 
 
 

For me, close to center is close enough. If you can neither feel a wobble nor see a wobble then it's close enough. The only real value of centering lie in its effect on where and how you put the opening hole. You want that hole to be as close to exactly center as you can get it. I do this by creating a dent in the top, letting my right thumb ride on the interior of the rim of that dent, then using it to guide my left thumb to the depth of my hole.
 
Like everything else in wheel thrown pottery it is best to use a smooth motion that moves at the same speed through the length of that motion. If you do this right they hole should make itself.
 
After that you need to make sure your opening fingers travel away from the center at an even distance from the bat. This allows the bottom to be even, and more importantly in this case, it keeps spirals from forming in the bottom. The excess clay in those uneven spirals comes from the walls of the pot which is now back to uneven. Uneven feels the same as uncentered.
 
Joel.

I do not recommend a Pacifica, we have one that is just a few months old and already we've had to replace the pedal and it feels like the bearings are going out. I don't like Brent for production use, but I think it would be a great studio wheel, and I like their kick/electrics. I know two production potters who love their VL Whispers, I personally don't like the RKs. I know one master potter who is pleased with his Bailey. I like the Soldner type of wheel, but they're a bit pricey for the average potter. Creative Industries makes cheap wheels, nuff said.
 
I strongly recommend trying the pedal first. Lots of people talk about power, but if you have a weak pedal you are much more limited than if you can't throw a 50# block of clay. I know a 110# woman who can center a 6# chunk of clay as well as I can, and I'm a stout guy. Precision trumps power IMO. However, if you are planning on centering 15 or 20 pounds, you may want to go for a stronger wheel. If on the other hand you are planning on turning out coffee mugs and pie plates, a responsive pedal is top of the list. I can throw on anything, but a touchy pedal, well, it just makes pottery not fun.

Them are lil' doodads. They're for fillin' in the empty spaces between big doodads.

I would find a similar object that doesn't leak and tap it lightly against something solid but not extremely hard. Then tap the two vases. It may be that they have dunted a little, but not enough to be real visible. I've seen pots with hairline cracks that reveal themselves by leaking. Other than that, if you are using a common glaze that you know vitrifies at cone 6, on a body that you know is supposed to vitrify at cone 6, and they both look normal, it seems likely to me they are both vitrified. If it is a new clay on the other hand, you may need to talk to your supplier. As Jim said, glaze doesn't always produce an in impermeable barrier.
 
Joel.

I'm sticking handles on these in this video. The clay is real soft so it is whipping at the ends. Other than that it went pretty well.
 
Joel.
 
 
 

I must apologize for the sound, we're shooting these on a point and shoot camera. I will try to dub over with some play-by-play when I can. I made a few of these yesterday but as I was going back to my studio I tripped and fell down the stairs onto some jagged flint rocks that make up much of my back yard. I gouged a chunk of hide out of my knee and banged myself up pretty good, so I've been laying low today and just got around to putting the pie plate video up. I have a couple more videos, including trimming the mugs, and making a utensile holder. And, when I get to feeling a bit better I'll trim some bowls I made yesterday.
 
 

Probably not. I personally don't care for Brent wheels but I'm a professional potter. At worst you may have gotten more wheel than you need with the 1hp motor. It you caught one on sale, for a little more, you could have gotten a brand new VL Whisper; a better wheel IMO. All in all though, unless the pedal is bad or something like that, you did perty good.