Crystalline Glaze Forum - excoboard.com

Poll

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Message

Avi Harriman
Administrator

Posts: 1060
Registered: Dec 2008

Posted September 10th, 2009 09:16 PM IP

I propose an EPK/Alumina/Biscuit SmackDown at Phil's. We have to glaze for the high fire reduction so let's all bring our own glue/material mixture. Let's show how we mix it, apply it and separate it after the firing. There will be no winners or losers. Only Knowledge Gained.

Quote:
Koz wrote:
And to think, so many of you folks use EPK instead of alumina hydrate in your glue mix.
Oh, Suuurrre.......go ahead and use it on your shelves to keep clay from sticking, but gosh, don't use it to keep clay from sticking from itself.

Yeah I know molecular structure shape of the two in comparison, blah, blah, blah, we've been through it all.

Hey Avi, you EPK guy, I'm gonna go glue myself to a post until we all get to Uncle Phil's, and then YOU'RE going to have to soak me in warm water overnight to set me free so I can put Dragon #6 back together.

Quote:
Bill Wrote
Besides preventing plucking, the alumina will act like tiny ball bearings to allow wide flat pieces to shrink and move easier.

Way back when (1970's) I used cut firebrick as pedestals, until I read the article by David Snair about making clay pedestals. He used alumina as a separator, but I often had chunks of the foot break away when I chiseled off the pedestal (we didn't know about the torch stuff back then). I did try different separating materials and found a mix of alumina & kaolin worked better. I also found scoring the glaze at the seam between foot and pedestal with a glass cutter worked well. I began using the "biscuit" mix for the pedestals back in 2003/04 and have stuck with that ever since. I think Ginny may now be using this for her pedestals as she has non-round bottoms on many pieces.

Be well, do good work, and keep in touch

Bill
Glaze Guru

Posts: 535
Registered: Dec 2008

Posted September 11th, 2009 08:25 PM IP

Quote:
Avi Harriman wrote:
I propose an EPK/Alumina/Biscuit SmackDown at Phil's. We have to glaze for the high fire reduction so let's all bring our own glue/material mixture. Let's show how we mix it, apply it and separate it after the firing. There will be no winners or losers. Only Knowledge Gained.

Since I won't be at Phil's for the get together, perhaps there's another who will carry forth the biscuit for me.

Bill

Bill Schran
wschran at cox dot net

Jeff Gieringer Artist-In-Residence Posts: 374 Registered: Jan 2009	Posted September 11th, 2009 08:34 PM IP Bill - I will be doing the biscuit thing. I wasn't sure how to answer the poll as I use glue and EPK to attach the biscuit to the pot, so I obviously answered EPK/Glue. Jeff "If you are lucky enough to find a way of life that you love, you have to find the courage to live it." John Irving. www.powdermillpottery.com www.powdermillpottery.blogspot.com

Koz
Clay Wizard/Court Jester

Posts: 1803
Registered: Jan 2009

Posted September 11th, 2009 10:10 PM IP

Alllllrrrriiighty THEN!

It's on.
I voted, the FIRST for alumina hydrate and glue!

Got a WHOPPING 8% of the popular vote!

O.K. so here's me standing in front of everyone in my alumina hydrate and glue underware.

Can you imagine? Trying to spread it around and get it to stick and cover and make sure everything is tucked in at the same time?
The globs falling and being caught, and the ones that weren't being scooped off the floor and re-applied until finally............

The material would start to yield to the atmosphere, time, and the hand of the master craftsman as it slowly set and hardened into a personal garment......

Talk about having to soak in warm water overnight.

O.K. so Avi,
You're on, Brother, GREAT idea.

I will BRING IT to Uncle Phil's!

I'm not even going to go into it here.
Maybe it just works on my clay body ONLY!

The porcelain one, I mean, not me, trying to soak off my close to permanent undies in the hot tub.

Some days it's tough to tell the difference.

Koz

Testify, Good People, Testify...
www.wizardofclay.com

Bill
Glaze Guru

Posts: 535
Registered: Dec 2008

Posted September 12th, 2009 08:16 PM IP

Quote:
Jeff Gieringer wrote:
Bill - I will be doing the biscuit thing. I wasn't sure how to answer the poll as I use glue and EPK to attach the biscuit to the pot, so I obviously answered EPK/Glue.
Jeff

Well **** Jeff!
I do the same thing.
But the pedestal is the biscuit, that's where your vote should be.
The folks voting epk/glue are using clay pedestals.

Throw your vote for the Biscuit Party! No new taxes!

Bill

Bill Schran
wschran at cox dot net

John Tilton
Artist-In-Residence

Posts: 357
Registered: Jan 2009

Posted September 12th, 2009 09:34 PM IP

I am beginning to feel like the EPK and glue mixture is not enough -- at least it is not perfect. I still have glaze that can get into the space between the pot and the pedestal, and those pots are the hardest to separate. I have a lap wheel that makes both surfaces very flat.

So I'm going to do some research on what might be better. There are several types of alumina -- alumina oxide and alumina hydrate and these have different mesh sizes too.

EPK is not the smallest clay particle that you might encounter, so why not use a white bentonite as part of the formula, where you need something (maybe) to fill in the EPK holes. The alumina particles will be bigger than the EPK -- What might exist between EPK and alumina that is very refractory and will fill up that hole? Maybe pyrophilite.

I think the problem could be described as finding a wad clay in which all the particle sizes are small.

John

Neil Simak Journeyman Crystallier Posts: 110 Registered: Jun 2009	Posted September 12th, 2009 10:43 PM IP I started off using Alumina/glue, but i found that even if the pedestal and pots bottom where completely flat glaze could still get under the two. Glenn woods turned me onto EPK/glue and it has worked great. except when I forget to sand one of the two (I'm pretty clumsy). Neil

Phil Hamling Everyone's Uncle Posts: 894 Registered: Dec 2008	Posted September 12th, 2009 10:51 PM IP EPK all the way! I want to grow up to be just like the best! http://puttgarden.com/crystal/2007/Page.html

robert troost Artist-In-Residence Posts: 276 Registered: Feb 2009	Posted September 12th, 2009 11:35 PM IP The method that works best for me is Calcined EPK,no glue, applied right before loading in the kiln. It,s all good.

Avi Harriman
Administrator

Posts: 1060
Registered: Dec 2008

Posted September 13th, 2009 11:16 AM IP

Quote:
Jeff Gieringer wrote:
Bill - I will be doing the biscuit thing. I wasn't sure how to answer the poll as I use glue and EPK to attach the biscuit to the pot, so I obviously answered EPK/Glue.
Jeff

Mea Culpa
I have to admit I set up a little bit of apples and oranges here. The topic was meant to be just glue but I added riser material by mistake to the poll. They do not allow even administrators to edit the poll lest we be accused of vote rigging.

Soooo... let's carry on the discussion about both items and we will expand the discussion slightly at Phil's

Be well, do good work, and keep in touch

Jeff Gieringer
Artist-In-Residence

Posts: 374
Registered: Jan 2009

Posted September 13th, 2009 09:03 PM IP

Avi, I will be bringing some good ole southern biscuits and gravy to Uncle Phil's. My gravy being of the EPK/Elmers type. I get a much cleaner departure with this combination, especially when both pieces are sanded nice and flat.

Jeff

"If you are lucky enough to find a way of life that you love, you have to find the courage to live it." John Irving.

www.powdermillpottery.com
www.powdermillpottery.blogspot.com

Phil Hamling
Everyone's Uncle

Posts: 894
Registered: Dec 2008

Posted September 13th, 2009 10:53 PM IP

Avi,
Like I said "EPK all the way1". You and I have covered this ground extensively in the past but thanks to this stinkin' poll I haven't been able to get it out of my head all day.
I thought besides seeing for oneself that EPK works better when it comes to catchers popping off pots, is there some other way to demonstrate the difference between the two. I believe alumina is wet by the glaze whereas kaolin is not.
Then I wondered if two little desert cups, one of kaolin the other of alumina, with a ball of Gold Stuff glaze, put through a crystalline firing, would show the difference.
Well stay tuned and we'll both find out.
Phil
http://www.puttgarden.com/crystal/2007/Page.html

I want to grow up to be just like the best!

http://puttgarden.com/crystal/2007/Page.html

Avi Harriman
Administrator

Posts: 1060
Registered: Dec 2008

Posted September 13th, 2009 11:45 PM IP

Quote:
Phil Hamling wrote:
Avi,
Then I wondered if two little desert cups, one of kaolin the other of alumina, with a ball of Gold Stuff glaze, put through a crystalline firing, would show the difference.
Well stay tuned and we'll both find out.
Phil
http://www.puttgarden.com/crystal/2007/Page.html

Phil,

My understanding of the difference between the two is that the alumina is shaped like little balls and the EPK, which is clay, is shaped like flat platelets. The alumina allows the glaze to wick in between the pot and and the riser while the the EPK seals the gap and forces the glaze run past. It will be interesting to see the results of your test

Be well, do good work, and keep in touch

John Tilton Artist-In-Residence Posts: 357 Registered: Jan 2009	Posted September 14th, 2009 07:30 AM IP What kind of Kaolin looks dark in color? John

Phil Hamling
Everyone's Uncle

Posts: 894
Registered: Dec 2008

Posted September 14th, 2009 07:40 AM IP

Quote:
John Tilton wrote:
What kind of Kaolin looks dark in color?

Moist EPK.

I want to grow up to be just like the best!

http://puttgarden.com/crystal/2007/Page.html

Ginny Conrow
Full Member

Posts: 98
Registered: Jan 2009

Posted September 14th, 2009 02:21 PM IP

OK...finally chiming in here. I am using Bill's mixture of sawdust, alumina and kaolin, then EPK and glue as separator.

I make mostly non-round pieces, so throwing pedestals isn't an option (although i could cut the clay into shapes, but this was time consuming and did not work well...). I don't spend a lot of time on the flat bottom bit, although my assistant does make the home made brick pedestals pretty flat and level so as to avoid any pot falling over issues and i do a quick sanding of bottoms for the same reason))

I don't mind a bit of time on the bench grinder, at which i have gotten quite skilled and fast! Who would ever have thought that being a potter would take me into grinding expertise!!

I believe the kind of clay we use may determine which separating system works best.

Ginny

Ian Artist-In-Residence Posts: 314 Registered: Dec 2008	Posted September 14th, 2009 02:34 PM IP It looks like i'm the only other person with Koz in the Alumina and Glue! It works fine for me, so i haven't really tried anything else. If it aint broke dont fix it. I'm looking forward to discussions at the reduction workshop. can we build a zero gravity kiln after we get all this reduction stuff down to a science?' Pottery Gangsta!

Koz
Clay Wizard/Court Jester

Posts: 1803
Registered: Jan 2009

Posted September 14th, 2009 03:21 PM IP

Ian,
Great idea........

I was thinking more along the lines of an zero gravity throwing room.

You could really float out some nice huge half and full baggers, that is if you have the "Right Stuff."

I guess you'd have to keep water in a spray bottle, or sip it from a straw and spit it out on the piece as you work, and magnetic or velcro tools so they would stay put on the table.

Plus we would need a belt or shoulder harness to hold us down to the seat.

Other considerations would arise perhaps once we got a test model going.

Koz

Testify, Good People, Testify...
www.wizardofclay.com

John Tilton
Artist-In-Residence

Posts: 357
Registered: Jan 2009

Posted September 14th, 2009 06:07 PM IP

Today I mixed up a mixture of equal parts

EPK
Calcined Alumina (fine)
Amorphous Silica
Bentolite - L
Pyrophyllite

To this I added Elmer's glue until it would stir up and then water to make it thinner. Screened it through a 60 mesh sieve.

Anne is glazing a pot with the new glue mixture tonight so we will see whether it works tomorrow afternoon. It might be good and it might be terrible.

John

Stephen Boehme
Artist-In-Residence

Posts: 248
Registered: Dec 2008

Posted September 15th, 2009 09:59 PM IP

Hi all I just saw the examples of the melted glaze results that Phil has posed at the puttgarden. It reminded me of a study I read recently about the best kiln wash or release for recycled glass. They did a thorough job of testing different refractories. I believe a mix of alumina and epk worked better than just one or the other. Having any silica at all in the kiln wash or release has been a bad idea for me. John Britt just had an awesome article on kiln wash in ceramics monthly. I was wondering about using some of the kiln wash formulas mixed with the glue a try.

here is the glass study, Its a labor intensive read, but i learned a lot from it
http://www.cwc.org/glass/gl002rpt.pdf

Steve

http://www.boehmestudioproductions.com/

Koz Clay Wizard/Court Jester Posts: 1803 Registered: Jan 2009	Posted September 15th, 2009 10:23 PM IP Oh my, I just opened that link, saw the title and got hit with the realization that I still need to learn how to read. I've been putting that off for just too long. But it has been a very peaceful existence. Koz Testify, Good People, Testify... www.wizardofclay.com

Phil Hamling
Everyone's Uncle

Posts: 894
Registered: Dec 2008

Posted September 15th, 2009 11:28 PM IP

Avi,
Sorry for the slow results posting. I had my umbilical hernia repaired today and have been a little distracted.
I thought it was pretty cool that a crystal formed in the center of each of these cups. Also I believe you can see that alumina is being attacked by the glaze much faster than is kaolin.
Phil
http://www.puttgarden.com/crystal/2007/Page.html

I want to grow up to be just like the best!

http://puttgarden.com/crystal/2007/Page.html

robert troost Artist-In-Residence Posts: 276 Registered: Feb 2009	Posted September 16th, 2009 11:47 AM IP Phil. Ouch on the hernia.So whatever you might think about lifting anything,DON,T.I,m having to have mine re-repaired because i didn,t take the time to heal.So please learn from my mistake.I,m a Kaolin man also and will demonstrate my technique in Oct.Good luck. It,s all good.

Avi Harriman Administrator Posts: 1060 Registered: Dec 2008	Posted September 16th, 2009 12:09 PM IP Fascinating difference between the two. Interesting the way the glaze separated from the EPK and fuses to the alumina. That demonstrates what is happening between the pot and the riser. Be well, do good work, and keep in touch

Koz
Clay Wizard/Court Jester

Posts: 1803
Registered: Jan 2009

Posted September 16th, 2009 01:13 PM IP

Avi,
Yes.......in SOME situations.

I am experiencing the EXACT opposite.

My clay body sticks to EPK, but not Alumina hydrate.

I don't know why, I don't care why.

It works for me, and I have a feeling that the Smackdown at Uncle Phil's will have very little influence on any REAL answers, or change anyone's preferance for one or the other.

Besides, Uncle Phil's tests are not duplicating the circumstance of glaze running OVER a join between pedestal riser and the foot of a piece.
If the join is tight enough, it flows right over it.
Phil's test is in DIRECT contact with it from the beginning, pooling and melting, and is a SUPERLATIVE test of a possible circumstance.

So we can all test our own situations, share glue recipes, try mine on his and hers on mine, get the stuff hot and see if we can get it off the riser clean and without chips.

Mine that I glue with the EPK will stick and chip, and everyone can see it for themselves.

It won't do them any good, because they will have to try my glue on their clay body, or their glue recipe on MY clay body.

I'll share my glue recipe, but not my clay recipe.

So as far as any REAL analysis of this whole thing, it either works or it doesn't.

Forgive me folks, but this is already getting to be a tiresome discussion.

As I have said before, I just do not analyze these things to this point.
It either works or it doesn't, then I go make more stuff using the method that does work.

Or maybe the alumina hydrate and glue 50/50 mix works for me because my pedestals just fit the foot of the piece so darn perfect EVERYTIME, I just NEVER have a problems because it just comes all too easy and naturally to me.

Yeah that's it. Piece of Cake.

Again folks please forgive me for the terse tone of my remarks.

I'm done venting, and will bring plenty of glue and alumina hydrate and little test pilots to Uncle Phil's for everyone to test glue recipes and use for some test glazes too.

O.K. I'm done.
Sorry.
Couldn't keep it in.
I'll see you all at uncle Phil's in my alumina hydrate underware.

Koz

Testify, Good People, Testify...
www.wizardofclay.com

Tax Journeyman Crystallier Posts: 154 Registered: Apr 2009	Posted September 22nd, 2009 01:07 AM IP Alohaz - one of the best sayings that I've ever read came from the Clay Art site - - - There are a thousand right ways to do something - - - - and no wrong ways. I love this sport Tax Alohaz from Aloha

John Tilton Artist-In-Residence Posts: 357 Registered: Jan 2009	Posted September 29th, 2009 02:20 PM IP My previous test was OK but not amazing. Which leads me to think about this. EPK Bentonite Zircopax That's my next test. John

Avi Harriman
Administrator

Posts: 1060
Registered: Dec 2008

Posted September 29th, 2009 02:26 PM IP

Quote:
John Tilton wrote:
My previous test was OK but not amazing. Which leads me to think about this.
EPK
Bentonite
Zircopax
That's my next test.
John

John, what was in your last test?

Be well, do good work, and keep in touch

John Tilton Artist-In-Residence Posts: 357 Registered: Jan 2009	Posted September 29th, 2009 06:56 PM IP Hey Avi, It is just above on September 14th. I think it has too many things in it and the silica is probably a no no. It was OK but not any better that just EPK. One thing that I don't like about EPK is that it leaves a residue that can be hard to remove. I'd like to find something that is so refractory that it just powders off. John

FotisK Artist-In-Residence Posts: 299 Registered: Jan 2009	Posted September 29th, 2009 07:25 PM IP Has any one used Zircopax only , mixed with clue? I know the melting point is very high. A friend of mine mixes it in his kiln wash. Fotisk

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Crystalline Glaze Forum :: DISCUSSION AREA :: THE VAULT: Useful Technical Threads :: EPK/Alumina/Biscuit SmackDown
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