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Benzine

Member Since 08 Sep 2012
Offline Last Active Yesterday, 09:36 PM
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Topics I've Started

Firing A "large" Slab

20 February 2014 - 06:38 PM

I recently had a student create a relatively large relief sculpture, as an independent project.  In the standard class, I also have the students make a relief sculpture, but the slabs are only 5.5"X8.5"X.5".  So I say "large" because in relation, the independent student's work is pretty big.  It's a circular format, with a diameter of 20"X.75-1".  When planning the project, he knew he wanted it to be big, so I just had him build it on a spare kiln shelf, to avoid potential breaks, while trying to move and load it. 

It's been drying for a couple weeks now, and has no spots, that feel cool.  So I'm not worried about residual moisture, but I've heard people suggest placing slabs on a layer of silica sand(?) or clay coils, to avoid stress during the firing.  The clay is low fire, so will this be necessary in either firing?

 

If it were my project, I'd just fire it, and deal with any issues that might arise, but as it's a student's project, and they put a lot of time into it, I don't want anything to happen to it.

 

Thanks for the help folks.


Repairing Projects

09 February 2014 - 11:47 PM

One of the joys of Ceramics, is destroying something, you just put your heart and soul in to.  It comes with the territory, but hey, odds are, it's your fault, and you know what you are doing.  Best case scenario, it's an easy fix, that won't take long.  Worst case scenario, you scrap it and start over.

 

But with teaching, neither of the above points are always true.  For one, they are students and are obviously just learning.  So they don't know how to fix broken ceramic ware.  So, in a teaching environment, it makes sense, to explain how to fix the project, and avoid a similar problem in the future.....Though usually, I explained that from the start.

But what happens, when the other point also isn't true, when a project is damage by someone, other than the owner?  Who do you have fix it?  Should the owner be required to take time out of their schedule, to fix something that shouldn't need it?  Should the guilty party do so, even the person can even be identified?  Should the teacher be responsible, since they are the expert and can probably fix it faster and more efficiently? 

 

What are your thought? 

I've done pretty much all of the above.  Normally, if someone breaks their work, have them fix it.  If I do it, then it excuses them from being haphazard with their work, and they'll do something similar again.  The big issue, is when someone else breaks a project that is not their own.  I had that happen recently.  A student threw a medium sized pot, and really had to fight it, to keep it from flopping.  They had a nice underglaze design, and it was drying on the the shelves.  I was loading greenware, and when I went to grab it, I noticed the telltale sign of "You picked up a greenware vessel incorrectly", that is the u-shaped break.  So I questioned them about it, the next day.  They swear they didn't break it.  I have no idea who did.  So I repaired it, and fairly well, if I do say so myself.

I'm sure I will always have those cases.  Unless I get cameras in my room, or someone's guilty conscience gets the best of them, I'll never know all that goes on....but as a teacher, I don't tell them that.  I AM ALL SEEING AND KNOWING, SO SPEAKETH THE ART TEACHER!!!!


Crack In Glazed Vase

25 January 2014 - 05:02 PM

I recently glaze fired this vase, and thought it came out of the kiln fairly well.

There was initially only some crazing on one of the glazes I used, which didn't concern me, as it was a decorative piece. 

However, several hours later, when I looked at the vase, these cracks had appeared.  Obviously, they are very much structural.

My first thought, is that they are stress cracks, that just didn't show up earlier in the process.  As you can see, one of them follows the curve, where the body meets the neck.  I had a bit of an issue with this area, when throwing.  It really wanted to "flop".  I'm guessing, this is where the initial structural problem arose.

I've just never had something crack this long after unloading it from the kiln. 

I plan to make a vase using a similar glaze combination in the near future.  So I'm trying to figure out if it was just a clay structure issue, or if the glaze fit, could have caused a crack this badly in the clay body?

Cracked Vase Top
Cracked Vase Side

 


Random Idea, I Thought I'd Try

10 January 2014 - 12:13 AM

So for whatever reason, I've had the idea for a while, to use a hollowed pumpkin as a reduction chamber for a Raku piece.

A few weeks ago, I finally had the chance, as I happened to have a pumpkin sitting around.  I wanted a bit more combustion, so I dried it a bit first.  Sadly, the made the top fit poorly, and not seal well. 

Nothing really big happened, but there are a few interesting spots where the color changed.   I really do like the inside, which I've never had turn out like that normally.

The middle bowl, is the one that went into the pumpkin.  The two outer bowls, were fired in metal bins, with newspaper.

Pumpkin Reduced Raku
Pumpkin Reduced Raku Top

 


Oops How Did That Happen?

05 January 2014 - 11:30 PM

So I recently had a situation, where a student project had a defect during a firing, the thing is, it went according to my plan.

In other topics, there have been discussions of accidentally breaking a student's project, but have you ever damaged a student's project (for whatever reason) on purpose?

 

I'll start.  There have been a few projects over the years, where I questioned their intended use.  So I'd make some alterations pre-bisque, like small holes or "cracks"  Also I just don't allow any small bowl type object, with notches in the top.  I'll tell the students to get rid of them.  If they don't, I'd take a fettling knife to the pieces, and I am not careful, or neat about it.

 

In regards to the project, that inspired this topic, I had a student make a nice coil pot.  It had some nice additive elements, and the student put a lot of time, both into the building and glazing.  However, the student kept asking odd questions, that made it sound like they wanted to use the pot.  The project isn't meant to create functional wares.  The project in question, would not be functional, for any legit purpose.  The student was also very adamant about me glaze firing the project.  They really wanted it back.  This was before the Christmas break, so I asked, if it was going to be a gift.  They said no, so I inquired further about why they needed it so soon?  They just said, they really wanted it.  The final straw was, when a couple of the student's friends came to look at the project, with big grins on their face.  I asked them why.  They didn't say.

So I decided I needed to do something about it.  I wasn't going to break the project, but I wanted to make it non functional, for any conceivable purpose, besides being purely decorative.  So, I fired it one evening.  When I came back in the next day, the kiln was still around 300 F.  Not terribly hot, but probably a little too warm, to be set next to an open window, where the outside temperature is around 0 F.  Sure enough I hear "ping, ping, ping".  Moments later, hey look stress cracks!.....

I put the project back in the kiln, and when I unloaded the kiln during class, "Oh no, that's too bad....."  I assured them, the cracks wouldn't affect their grade, and it will still look quite nice. 

The student really wanted to find a way to fill the cracks.  I said there weren't any.  "Couldn't we put glaze in there"...NOPE!  And even worse, the student asked if they could come in next term, and make another coil project.  They even offered to pay for the materials.  I said, no.