[Nelly]

Dear All,

I have just put in a load of low fire clay that has been bisqued to cone 4 and is now being glaze fired at 05.

My issue is that I think I mixed the jars up when applying the commercial final glaze. I think rather than putting a product on called "crystal clear" I put "white" underglaze on the already bisque/underglaze decorated pieces.

Here are my thoughts:

If I did make this mistake what will happen is that I will have pots come out that are more fully baked but will have a white color. The bright underglaze colors originally applied may or may not show through. There may be slight shadows under the white underglaze where I should have had clear glaze.

I cannot at this point remove the white underglaze. The kiln is on and firing. My mistake is in progress.

What I can do, however, I think, is to remove them when they are completely fired and refire the whole lot. I think the solution is to refire one level up (i.e., 04) AND apply the appropriate clear glaze before they go into the kiln again. This will produce some sort of effect?? Cloudy looking pieces with a clear surface.

I can't believe this happened?? I will not bore you with the excuses of why this error occurred but I just want to know from the group, is this what you would do if you made this error? Will the second time fired pieces (fired to maturation temperatures) hold the glaze?

If you fired to cone 05 would you refire to cone 04 with the appropriate clear glaze on the surface? If anyone has any suggestions or if my thinking on this process is incorrect I would appreciate any responses.

Nelly

[Marcia Selsor]

nelly,
if you are talking about the difference between cone 04 and05 there should not be a big problem. The cone 05 is one cone cooler than the 04 . You should be able to reapply a glaze to this white underglaze. It is still in the bisque range temperature.
Marcia
On the road in Belgium

[Lucille Oka]

If I had just loaded my kiln, and I thought that I made a mistake in the glaze, I would shut off the kiln, wash off the glaze and start again. Now if you just want to see what you will get and hope that it will be fantastic well that is the situation that you are in just now. Did you make a error in your post you said you bisque fired to cone 4 did you mean cone 04?

[Nelly]

Lucille Oka, on 08 September 2012 - 12:15 AM, said:

If I had just loaded my kiln, and I thought that I made a mistake in the glaze, I would shut off the kiln, wash off the glaze and start again. Now if you just want to see what you will get and hope that it will be fantastic well that is the situation that you are in just now. Did you make a error in your post you said you bisque fired to cone 4 did you mean cone 04?

Yes, I meant 04.

I do agree with you. I could have unloaded the entire kiln and just washed. But I am hoping beyond hope that in preparation for this group to glaze yesterday that I DID put out the right jars. I am, however, anticipating the worst case scenario.

And no, this is not my stuff in the kiln. It was a kids party and their work.

Will keep you posted.

Nelly

[Nelly]

Marcia Selsor, on 08 September 2012 - 12:09 AM, said:

nelly,
if you are talking about the difference between cone 04 and05 there should not be a big problem. The cone 05 is one cone cooler than the 04 . You should be able to reapply a glaze to this white underglaze. It is still in the bisque range temperature.
Marcia
On the road in Belgium

Dear Marcia,

Thank you for your response. It was a total error on my part?? I should have checked before everyone started to paint. Anyway, thank you.

Have fun in Belgium.

Nelly

[Mark C.]

Dear Marcia,

Thank you for your response. It was a total error on my part?? I should have checked before everyone started to paint. Anyway, thank you.


Nelly
[/quote]

Nelly
Many customers over the years think we bake and paint and cook the pottery-I suggest calling glazing glazing instead of painting-yes you can paint glaze but it really is just a way to apply glaze -this is a small point but public eduction begins with us.
We fire not bake - that sort of thing is up to us to promote.
Just a suggestion.
Mark

[Nelly]

Mark C., on 08 September 2012 - 11:59 AM, said:

Dear Marcia,

Thank you for your response. It was a total error on my part?? I should have checked before everyone started to paint. Anyway, thank you.


Nelly

Nelly
Many customers over the years think we bake and paint and cook the pottery-I suggest calling glazing glazing instead of painting-yes you can paint glaze but it really is just a way to apply glaze -this is a small point but public eduction begins with us.
We fire not bake - that sort of thing is up to us to promote.
Just a suggestion.
Mark
[/quote]

Dear Mark,

Yes, I was using fairly common language wasn't I?? Thank you for pointing this out. I don't want to be offensive to any professional artists. This is just my hobby. I can appreciate that you want people to use language in keeping with this particular domain of art. I will try to remember this is my postings.

Nelly

[TJR]

Nelly;
This is called developing a vocabulary of terms. It is important to use the correct terms with students and children, otherwise they won't learn the wording. I don't bake, I FIRE!!!
Tom [TJR]

[Mark C.]

Even as a hobby learning the terms is a good thing-just as important as learning how to glaze fire hand build or throw-all part of the whole.
For me its 40 years of educating the public at shows when I'm asked if I bake the ware or paint it.
Mark

[Nelly]

Mark C., on 08 September 2012 - 08:00 PM, said:

Even as a hobby learning the terms is a good thing-just as important as learning how to glaze fire hand build or throw-all part of the whole.
For me its 40 years of educating the public at shows when I'm asked if I bake the ware or paint it.
Mark

Dear All,

I have now unloaded the kiln. Turns out that most of the ware WAS decorated with the clear. jar. I can see where there are some spots where the white was applied but it is nothing that extraordinarily bad.

Thank you one and all for the advice.

Here is what I learned:

1. When in doubt, unload kiln, wash, dry, reapply glaze to ware.

2. Check labels twice or three times if the color in the jar appears the same.

3. Remember to use the appropriate language when describing this art form.

4. If I had made this error that I could reglaze and refire to cone 04 as I planned. My original idea was I think, correct.

Thank you again. I am truly sorry if I offended anyone with my use of language.

Nelly

[Mark C.]

The turn off kiln and wash the ware is what I first thought when you 1st posted this-glad you realized this for next time.No one was offended especially me on terminology just trying to get it right

On a side note I cannot tell you how many times I have messed up glazes either mixing (phone rings and my check list goes down the tubes)or firing-it just happens-wrong glaze on ware is very common error for just about everybody at some point.
The take away is learning for next time.
Mark

[Nelly]

Mark C., on 08 September 2012 - 10:32 PM, said:

The turn off kiln and wash the ware is what I first thought when you 1st posted this-glad you realized this for next time.No one was offended especially me on terminology just trying to get it right

On a side note I cannot tell you how many times I have messed up glazes either mixing (phone rings and my check list goes down the tubes)or firing-it just happens-wrong glaze on ware is very common error for just about everybody at some point.
The take away is learning for next time.
Mark

Dear Mark,

Exactly. The take away is the reading of the labels and having focus during important times such as glaze application.

It also speaks to my neurosis when firing other people's work. I knew the work of mine that I put in the kiln was correctly glazed. I am fastidious about this and am usually alone when I am working. It was their work that scared me especially after seeing the two similar jars on the table.

Yesterday the glaze application process occurred in a group. There was lots of chatter and after school playfulness as they worked from bowls of poured glaze.

It was when I saw the jars sitting on the table later that I realized both were white, both were in the same sized containers and had approximately the same amount gone from each. Then my imagination went wild.

The good news though is that after seeing their work tonight, I know they will be extremely pleased to see their dragons, turtles and little pinch pots. Like anyone who fires, they will remember each and everything that went into the kiln. They will have recollection of their color scheme --this was where my worry laid. I am sooo pleased to see nothing was really damaged.

So yeah, I have learned an important lesson. Focus. And don't push the panic button until you are 100% sure you have made an error in supervision/instruction.

I will end my worry about this project right now and won't bother the forum with this neurotic outburst further.

Nelly

[Marcia Selsor]

Nelly,
you would not be the first one to make such a mistake. Glad you listed what you learned from the experience. Experience is the best teacher.
I am glad to know nothing drastically bad happened. And yes, when in doubt unload and wash off.

Marcia

[Lucille Oka]

Nelly, is it possible for you to separate your glazes from your underglazes at least put them on different shelves? Adding labels on the shelves can help. Also be sure the students are aware of what they will be doing that session and have them check the jars. If you are overwhelmed you can try selecting a monitor that set out the glazes or underglazes for the session and just leave you to check it.

[AndyL]

You might try taking an industrial magic marker like a Sharpie and marking the lids and Jars with a ^symbol & number.

[Nelly]

AndyL, on 09 September 2012 - 11:15 AM, said:

You might try taking an industrial magic marker like a Sharpie and marking the lids and Jars with a ^symbol & number.

Another really good point. Awww...the lessons I have learned this summer. I could write a litany.

Nelly