Firing Program For new to pottery/ceramics

[Gal Levy]

Hi,

Me and my wife new for ceramic and pottery, We did some work and the glaze goes with lots of pinholes,

We have new nabertherm top 80 with 400 controller, That has 4 segment

We use 264 pottery passion clay, Did the basic bisque and then 3 layers of bellssimo (colorobbia) glaze, Fire with glaze 1180 program

 

I want to know what we can do? Maybe program tips of the bisque or the glaze firing (the controller has 4 segment with temp of each segment and time or rate

Or any other tip to solve it

Thanks very much

[Babs]

A photo of pinholes would help a lot. 

Could help to slow down last segment of firing and add a 10 minute soak at end.

If not pinholes but blisters..could be an overfiring so photos definitely would assist best diagnosis.

 

[Gal Levy]

22 minutes ago, Babs said:

A photo of pinholes would help a lot. 

Could help to slow down last segment of firing and add a 10 minute soak at end.

If not pinholes but blisters..could be an overfiring so photos definitely would assist best diagnosis.

 

 

Thanks very much for the fast response

Attached picture and screenshot of firing program tool

[neilestrick]

If you're firing to cone 5, set your last 100C degrees to a rate of 60C/hr, and a peak of 1186C. On the schedule you've shown it looks like you're going too fast, which is not giving the glaze time to settle and/or develop enough heatwork.

[Gal Levy]

8 minutes ago, neilestrick said:

If you're firing to cone 5, set your last 100C degrees to a rate of 60C/hr, and a peak of 1186C. On the schedule you've shown it looks like you're going too fast, which is not giving the glaze time to settle and/or develop enough heatwork.

Thanks very much,

You can help me please to fill the 4 segment?

Two programs, 1 glaze for earthware (cone 06 i think) and also stoneware

[neilestrick]

15 minutes ago, Gal Levy said:

You can help me please to fill the 4 segment?

Firing  programs don't have to be any thing complicated. The most important thing is the last 100C degrees, as the rate of climb in that segment will determine the heatwork. I start all of my programs with a preheat segment where I adjust the hold time as needed to dry things out:

Cone 5 Stoneware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for dry pots.

2. 175C/hr to 1086C, no hold.

3. 60C/hr to 1186C, hold as long as needed. You only need a hold if you need a little more melt from your glazes.

4. You can use this segment for slow cooling, if desired.

Cone 06 Earthenware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for totally dry pots unless they're thick.

2. 150C/hr to 898C, no hold.

3. 60C/hr to 998C, no hold.

[Gal Levy]

7 hours ago, neilestrick said:

Firing  programs don't have to be any thing complicated. The most important thing is the last 100C degrees, as the rate of climb in that segment will determine the heatwork. I start all of my programs with a preheat segment where I adjust the hold time as needed to dry things out:

Cone 5 Stoneware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for dry pots.

2. 175C/hr to 1086C, no hold.

3. 60C/hr to 1186C, hold as long as needed. You only need a hold if you need a little more melt from your glazes.

4. You can use this segment for slow cooling, if desired.

Cone 06 Earthenware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for totally dry pots unless they're thick.

2. 150C/hr to 898C, no hold.

3. 60C/hr to 998C, no hold.

Ok, I will try this

Thanks again for the help

[rox54]

I am self taught but will offer from my own experience. Could the pinholes be caused by a thick glaze? I've had success by thinning my glaze.

[Gal Levy]

On 10/12/2021 at 5:05 PM, neilestrick said:

Firing  programs don't have to be any thing complicated. The most important thing is the last 100C degrees, as the rate of climb in that segment will determine the heatwork. I start all of my programs with a preheat segment where I adjust the hold time as needed to dry things out:

Cone 5 Stoneware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for dry pots.

2. 175C/hr to 1086C, no hold.

3. 60C/hr to 1186C, hold as long as needed. You only need a hold if you need a little more melt from your glazes.

4. You can use this segment for slow cooling, if desired.

Cone 06 Earthenware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for totally dry pots unless they're thick.

2. 150C/hr to 898C, no hold.

3. 60C/hr to 998C, no hold.

Hi,

So I tried the cone 06 program, It turns out great, no pinholes but after cooling the object makes cracking sounds (for 12 hours till now) But the surface looks ok

its normal?

Thanks

[Bill Kielb]

4 hours ago, Gal Levy said:

its normal?

This is usually an indication of a glaze fit issue. Presuming all are rated for cone 06 and now fully melted then this would indicate this glaze and this clay have different enough coefficients of expansion that when fired together they do not fit. Hence the noise, and hence the likely crazing. You may have to look very closely but you ought to notice you likely have very fine cracks in the glaze. This is generally considered a glaze defect and a suitable glaze is found that will not do this. The firing schedule is a good one and ought to be confirmed with cones, do you confirm with witness cones?

can you confirm what cone your clay and glaze are designed to fire to?

[Gal Levy]

4 hours ago, Bill Kielb said:

This is usually an indication of a glaze fit issue. Presuming all are rated for cone 06 and now fully melted then this would indicate this glaze and this clay have different enough coefficients of expansion that when fired together they do not fit. Hence the noise, and hence the likely crazing. You may have to look very closely but you ought to notice you likely have very fine cracks in the glaze. This is generally considered a glaze defect and a suitable glaze is found that will not do this. The firing schedule is a good one and ought to be confirmed with cones, do you confirm with witness cones?

can you confirm what cone your clay and glaze are designed to fire to?

Hi,

This is picture of the clay And the glaze, 
I did neilestrick cone 06 program after normal bisque on my kiln

Cone 06 Earthenware Program

1. 60C/hr to 85C, hold as long as needed. No hold needed for totally dry pots unless they're thick.

2. 150C/hr to 898C, no hold.

3. 60C/hr to 998C, no hold.

 

Maybe I Should do the cone 5?

[Bill Kielb]

@Gal Levy
Your clay fires to 1280c which is cone 10, so firing to 06 will only sinter it and it will not be fully melted or vitrified. As a result, it will be very porous and will weep when filled with liquid  …….. and it’s expansion properties a bit unknown since it’s not fully baked. The glaze you are using is a lowfire product and matures cone 06/05.  It’s generally a good idea to use a glaze and clay that mature at the same temperature. If you are only working at lowfire temperatures 06/05 then you most likely want to use a lowfire clay that matures in the 1000c range. When the clay and glaze match in maturing temperature you can then find glazes that fit well with the clay reasonably reliably. Fitting this clay but under firing it always will have too much of a variety of results to depend on. 
 

@neilestrick gave a very acceptable schedule to begin achieving uniform cone results. Clay really needs to be fired to a cone, not necessarily a peak temperature. The effect of heat over time is very important to fully maturing things in ceramics.  The schedule is not the issue, the products used are. The schedule is pretty universal as to how to more correctly measure heatwork though so understanding it will help greatly in the future no matter what cone you end up firing to.

[Gal Levy]

38 minutes ago, Bill Kielb said:

@Gal Levy
Your clay fires to 1280c which is cone 10, so firing to 06 will only sinter it and it will not be fully melted or vitrified. As a result, it will be very porous and will weep when filled with liquid  …….. and it’s expansion properties a bit unknown since it’s not fully baked. The glaze you are using is a lowfire product and matures cone 06/05.  It’s generally a good idea to use a glaze and clay that mature at the same temperature. If you are only working at lowfire temperatures 06/05 then you most likely want to use a lowfire clay that matures in the 1000c range. When the clay and glaze match in maturing temperature you can then find glazes that fit well with the clay reasonably reliably. Fitting this clay but under firing it always will have too much of a variety of results to depend on. 
 

@neilestrick gave a very acceptable schedule to begin achieving uniform cone results. Clay really needs to be fired to a cone, not necessarily a peak temperature. The effect of heat over time is very important to fully maturing things in ceramics.  The schedule is not the issue, the products used are. The schedule is pretty universal as to how to more correctly measure heatwork though so understanding it will help greatly in the future no matter what cone you end up firing to.

Hi,

So I will try next time the cone 5 glaze program? In the glaze website its looks that it is ok

[Bill Kielb]

33 minutes ago, Gal Levy said:

So I will try next time the cone 5 glaze program? In the glaze website its looks that it is ok

So it may fit better with another glaze and this time fired to cone 5: however the point was you have cone 10 clay, your goal should be to match that. If you fire cone 10 clay to less than cone 10 then the results can be less than ideal as well as predictable.  I would suggest to Research clay and vitrification or clay and firing to maturity.

here is a nice article that may help  https://digitalfire.com/glossary/maturity

 

[Babs]

Magical stuff indeed if it accommodates such a wide temp range, glaze also!!.

The fact that the glaze is pinging at the low firing  indicates it is not happy with the body it is sitting on..

A big broad sweeping statement from the Company!!!!

Better to decide on a body and glaze  wich fall withingb a narrow band imo. Cone 5_6 will give you a great choice of glaze and claybody .

[Gal Levy]

Hello,

Thank you very much to everyone who helped,

we did an experiment on a fire dish in the program you wrote for us and the glaze came out fine, but the dish warped a bit (folded) maybe also our bisque program is wrong (there is a screenshot above,) it only reaches 900 degrees and if possible  Please recommend a bisque firing program with only 4 segments, thank you very much in advance

[Bill Kielb]

20 hours ago, Gal Levy said:

we did an experiment on a fire dish in the program you wrote for us and the glaze came out fine, but the dish warped a bit (folded) maybe also our bisque program is wrong (there is a screenshot above,) it only reaches 900 degrees

I am not sure what is really happening here, but it sounds now as if this clay is possibly over fired and slumping which for cone 10 clay would be very odd fired to cone 5. So I strongly suggest to post a picture of the folded ware so folks can see what this really is.  I also strongly suggest you post how the test was conducted but expressed in the cone you bisqued to as well as the cone you glaze fired to.

My feeling  is it’s really, really, really important that you understand the basics of how and when things are mature and the function of cones to successfully diagnose what is happening and to avoid all types of fit issues in the future. Knowing how to schedule a bisque firing or glaze firing is useful but you will be far more likely to be successful once you learn a bit more about the basics of ceramics.

Creating a bisque schedule is easy, usually 9 - 12 hours to burn out most organics, so pick a speed that will take that long ( about 75 - 100c per hour) and the last 100c of the firing go 60c per hour to reach your desired cone ( generally cone 04-06) from the cone chart. See, there is that cone thing again ………. I think knowing a bit about it will help a great deal in the future IMO.

[Babs]

On 10/23/2021 at 3:46 AM, Gal Levy said:

Hello,

Thank you very much to everyone who helped,

we did an experiment on a fire dish in the program you wrote for us and the glaze came out fine, but the dish warped a bit (folded) maybe also our bisque program is wrong (there is a screenshot above,) it only reaches 900 degrees and if possible  Please recommend a bisque firing program with only 4 segments, thank you very much in advance

 

On 10/16/2021 at 6:59 AM, Gal Levy said:

Hi,

So I will try next time the cone 5 glaze program? In the glaze website its looks that it is ok

This statement is about the glaze.

The concern you have is that your clay body being cone 10 will not be mature enough at that temp/ heatwork done to hold liquid. Also may introduce probs re getting a cone 5 glaze to fit the body.

Most folk have gone to higher cone and temp for bisquing for a number of reasons. 

I fire to 1000dgc with a 10 minute soak because I tumble stack my kiln and want to equalise the temp throughout.

Unless you have purchased a heap of that clay  , go for a midfire clay body.

Sculptural stuff you could get away with,if sculptures for indoors.

Outside, portIus clay freezes  water expands within....you know the rest.

Keep at it.

[oldlady]

sorry if i am butting in but what i see is that Gal Levy needs a cone chart.   and someone emphasize the difference between numbers starting with 0 and those that do not.   hundreds of degrees difference.   read the large type post   (orton 08-7) cone.

[Babs]

On 10/16/2021 at 6:59 AM, Gal Levy said:

Hi,

So I will try next time the cone 5 glaze program? In the glaze website its looks that it is ok

Yet on the bottle you photographed the glaze is for c06 to c05 just over 1000degC. Your clay body only bisqued at that point ...

So you need: 

Clay and glaze maturing around c 06 to 05, the lower the cone number preceded by an 0 the higher the temp and the opposite with no preceding zero...are you still with me????

Or you fire to c10, why would you?

May need a different kiln, very expensive firing.

Or clay body and glaze maturing at the same temp , whatever you choose.

And you thought it was a simple pinhole issue...

Can be if you are making them just for yourself and you don't mind a bit of porosity, and shorter life of pots, dont leave them on auntie's french polished grand piano with a latte in them....