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Biglou13

Campana Kiln Wash

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Just made recipe

 

2500 epk

2500 glomax

5000 alumina

4250 h20

20 Darvan

 

 

It's settling like mad.

 

 

Only what is alumina. That is how bag is labeled. I'm guessing I had wrong one

 

Alumina hydrate vs alumina oxide........

 

At this point I may "floc". To suspend???!!!!

 

Frustrated.........

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Potters often toss around the term "alumina" and can mean EITHER one of the ones you mentioned.  USUALLY it is alumina hydrate... because it is cheaper.

 

If you went over on the Darvan... that could be the settling issue. Amount is "one single drop" critical.

 

But you are also WAY heavy on non-suspendables in that recipe.

 

best,

 

...................john

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Grams are often not close enough on defloculants. The usual approach is to add almost all of it,.... but not all.  Then drop by drop... add in the last until you get what you want. Local water chemistry affects things.

 

best,

 

....................john

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The other thing is bottle is just marked darvan.

 

I'm desperation I added flocs just enough to suspend.

 

Second thing was shelves need to be near saturated prior to application just sponged wet and it dried instantly

 

There were a few shelves different than the rest that were outside after grinding and got rained on these performed as in pictures and self leveled.

 

I'm pretty sure I didn't have alumina hydrate it's supposed to suspend better.

 

Majority of shelves have uneven wash on them I may sand lightly tomorrow. (Group studio is closed no one will see bad shelves)

 

Any thing will be better than what was there to start with.

 

I'm chalking this experience up to "testing"

 

What's your opinion on washes that add a bit of flux. Eg nepsy?

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Biglou13

 

Per the link from Min, Glomax should be 2500g. Is the 2599 in your recipe a typo?

 

-SD

Corrected

Yes typo

 

Since shelves are uneven from rough application of kiln wash, I'm planning a light sanding to even out surface. Pros, cons?

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Grind them as flat as you can-what are they made of?????

-kiln shelves come in many flavors

Mark

Are they silcon carbide?

mullite?

dry pressed high alumina or

advancers

or chinese advancer knock offs?

just plain electric mullite shelves?

Many flavors my friend

Mark

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Yes I found out fast. The first shelf has some battle scars......... (Thank god the shelf wash hides those)

I now use grinder with diamond pad parallel to surfaces. I think it would be smarter now to get rigid backing pad vs. semi.

50 grit pads worked well, almost too well. I'd suggest using 100 grit unless there is glaze direct on shelves. 200 was pretty much waste of time. I grounds 5 22" full shelves and 2 1/2 shelves in under an hour. Making shelf wash and coating is another issue. [All while Getting sassed at studio for leaving extension cord out is another issue, after donating my time, including research, buying grinder, buying diamond pads, buying 1/2 face mask, cutting my Hand on crappy shelves, grinding shelves, making kiln wash, coating shelves, cleaning after coating, drying, cleaning area after coating indoors, drying, re hand sanding to soften texture, then running a low temp dry cycle on the kiln that I change relays and wiring harness that layer defunct for years prior to my arrival, diagnosed further issues. that I ran QC and tested to get a perfect cone six top to bottom, all as volunteer and as donated time, not to mention the spectacular glaze gallery I'm developing (ok they had two dipping non commercial glazes before I showed up). Mopping the studio multiple times, the whole studio.Then you have the gall to put notes around the studio accusing me wrongly of leaving a mess , with my name on it. (Slander) To some one who as donated considerable time and monetary value to studio, you just barked up the wrong tree. Maybe I I have old school standards but I will not and cannot tolerate your disrespect!!!!!!!!!...don't you know I love pottery I have no agenda.........I hope you read this......Rant off] as you previously may have read there are 2 readily available alumina' one suspends better than another. Clarify which one before using.

 

After action report.....

 

So much of the shelves drank up the wash leaving them a bit textured after wash.

The two that were left in the rain, were some what saturated these two (1/2 shelves) actually "self leveled" the kiln wash as stated in article.

But that was due to the shelves not eating up wash, (because they were wet) Like a dry piece of bisque eats up a glaze.

These to cracked a bit (slightly...think parched earth in a few spots ) , thinner coating than others, no biggie I'll add more coats as necessary. One shelf needed up with a greenish tint ( I'll let u chemistry gurus mull on that). The others after bisque fire came out white coated well, no cracking no peeling. But even with post coating pre bisque sanding , Have some texture, and some shelves are coated somewhat "thickly".

 

Well the true test will lie in cone 6 firing. ........ Later this week. Report later

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If you soak the shelves to get the self leveling....... you may find that you have to let them dry a long time before use. 

 

DO NOT get Advancers wet!!!!!!!!!!!  The explode... with GREAT force.  Even when you THINK they should be dry.

 

best,

 

.....................john

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