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Marcia Selsor    1,301

Yes, I am doing this in Oct.in Minneapolis. What did the beet juice do? I love beet juice color and even ate beets baby food when I was a baby. (whew that is literally ancient history).

I see all those pieces in the link have brownish tint. very nice surfaces too. Mine are black and white. I was using porcelain scraps with 5 different additives to the clay body: coffee grounds, perlite, kitty litter, sawdust, and brass filings. I liked the perlite the best.The kitty litter didn't work as well. I have used it before a long time ago. This modern fragrant absorbent stuff didn't hold up.I think the brass filings could be rolled onto the surface. All these were had built.

 

The you tube above shows the process although my results were different from these. These look like they were polished with terra sig.

 

Benzine, using a glaze would prohibit the absorption of the brew and carbon. But as always, try it and see.

Marcia

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Marcia Selsor    1,301

As a chemist, I can't see any real reason to ferment the brew you dunk the pots in. Any kind of foaming from the CO2 would not seem to make much difference. The oxidation smoking of the charred organics in the mix is what gives the color.

Has anyone tried it without fermentation?

 

It seems like you could get even more wild effects by adding other chemical to the mix like copper carb or iron chloride. Also thickening with gelatin or even adding cooked angel hair noodles stirred up so they would adhere to the pot when you pulled it out 

 

From the videos I've seen, It looks like the real trick is how long you immerse and quench the piece, and what the temp it actually was when it went in. Some of the pieces in the videos were a heck of a lot cooler than 1600 F.  It looked like, if the pots were cooler, then the patina was more brown and it they were put in real hot, the patina was black, just due to carbon formation. Some of he videos were pretty bad though. Hard to see how how hot the pots were though they didn't seem to be glowing like you would expect at 1600F.

 

I've done a lot of pit fires and 1600F is probably hard to reach but I'm not sure you have to be even very close. I would bet that you can get the same effect even at  eight or nine hundred. It would be worth a try.

I had 10 pieces in the kiln. I could get 2 out and through the process before the kiln dropped below 1500. Then the process didn't seem to work. A bubbly Scum solidified on the surface.So 1650 is the best temp. from my experience.

Marcia

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Yes, I am doing this in Oct.in Minneapolis. What did the beet juice do? I love beet juice color and even ate beets baby food when I was a baby. (whew that is literally ancient history).

I see all those pieces in the link have brownish tint. very nice surfaces too. Mine are black and white. I was using porcelain scraps with 5 different additives to the clay body: coffee grounds, perlite, kitty litter, sawdust, and brass filings. I liked the perlite the best.The kitty litter didn't work as well. I have used it before a long time ago. This modern fragrant absorbent stuff didn't hold up.I think the brass filings could be rolled onto the surface. All these were had built.

 

The you tube above shows the process although my results were different from these. These look like they were polished with terra sig.

 

Benzine, using a glaze would prohibit the absorption of the brew and carbon. But as always, try it and see.

Marcia

 the beet juice and or sauerkraut juice (red) is supposed to stain the mixture giving more reddish brown hues.  I have not had any success with this, I may have to puree the whole can(s) versus just straining the juice off.

 

In the video none of the pieces were terra sigg'd.  I have found it occasionally flakes off in the process, and when it does stay I haven't noticed enough of a difference to include that step.

 

Chad

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Marcia Selsor    1,301

 

Yes, I am doing this in Oct.in Minneapolis. What did the beet juice do? I love beet juice color and even ate beets baby food when I was a baby. (whew that is literally ancient history).

I see all those pieces in the link have brownish tint. very nice surfaces too. Mine are black and white. I was using porcelain scraps with 5 different additives to the clay body: coffee grounds, perlite, kitty litter, sawdust, and brass filings. I liked the perlite the best.The kitty litter didn't work as well. I have used it before a long time ago. This modern fragrant absorbent stuff didn't hold up.I think the brass filings could be rolled onto the surface. All these were had built.

 

The you tube above shows the process although my results were different from these. These look like they were polished with terra sig.

 

Benzine, using a glaze would prohibit the absorption of the brew and carbon. But as always, try it and see.

Marcia

 the beet juice and or sauerkraut juice (red) is supposed to stain the mixture giving more reddish brown hues.  I have not had any success with this, I may have to puree the whole can(s) versus just straining the juice off.

 

In the video none of the pieces were terra sigg'd.  I have found it occasionally flakes off in the process, and when it does stay I haven't noticed enough of a difference to include that step.

 

Chad

 

They came out really smooth. Nice brown color.

 

Marcia

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Marcia Selsor    1,301

Made six new clay tests for my next Obvara firing. I have jury duty starting next week, so the firing will be on a weekend in the future.Additives include rice, macaroni, paper and perlite.The resulting pitting seems to attract the carbon spotting. I like that.

 

Marcia

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Marcia Selsor    1,301

There are several more you tube videos out there on firing obvara. Jane Jermyn has been doing workshops in Europe. Her site lists several more ceramicist using obvara.

 

 

 

Jose Ramos

 

 

Marcia

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Benzine    610

Great videos.  Thanks Marcia.  I am very tempted to try this.  I still need to get my Raku kiln altered a bit.

 

How was it, that in the second video, he got one half to turn brown, and the other black?

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Marcia Selsor    1,301

Maybe its the temperature when they hit the solution. Clay body?

Can't say. Up in Smoke's pieces are brown. Mine were black mostly.

what's up with your raku kiln?

 

Marcia

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Benzine    610

Maybe its the temperature when they hit the solution. Clay body?

Can't say. Up in Smoke's pieces are brown. Mine were black mostly.

what's up with your raku kiln?

 

Marcia

It wasn't quite getting up to temperature.  We've talked before, about my needing to possibly widen both the intake, and exhaust ports.  I just haven't got to it, as I haven't fired in months.  The kiln gets to about 1600 F currently, and just hangs out there.  Plus, it takes a while to get there, longer than the time it takes the average, similar style Raku kiln to fire anyway.  The glaze is seems to be just below maturity, when the kiln temperature plateaus.

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jchas    0

I started using this technique about a year ago. I am hooked and I am looking for as much as I can about the history.  I have been on Jane's Facebook page, but I can't find any specifics.  If anyone has any information on where to get published information and history, I would love that.  I will upload a few pictures...as soon as I figure that out.  post-58852-0-57190600-1375887285_thumb.jpgpost-58852-0-92092200-1375887304_thumb.jpgpost-58852-0-00863400-1375887337_thumb.jpgpost-58852-0-73361600-1375887348_thumb.jpgpost-58852-0-91471700-1375887365_thumb.jpgpost-58852-0-60821200-1375887374_thumb.jpgpost-58852-0-93887800-1375887381_thumb.jpgpost-58852-0-68422700-1375887396_thumb.jpgpost-58852-0-94907400-1375887405_thumb.jpgpost-58852-0-94907400-1375887405_thumb.jpgpost-58852-0-94640900-1375887423_thumb.jpgpost-58852-0-59971900-1375887436_thumb.jpg

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Wyndham    98

Marcia, what's the percentage of pieces breaking from thermal shock in the first or second dunking?

Wyndham

 

Edit, this could make some great Bonsai pots, hummn

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Marcia Selsor    1,301

Marcia, what's the percentage of pieces breaking from thermal shock in the first or second dunking?

Wyndham

 

Edit, this could make some great Bonsai pots, hummn

for me , zero.

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Marcia Selsor    1,301

When dunking a hot pot, it is important not to let it flip over. The steam could blow it up. Keep a firm hand on the tongs and dip a few gentle times, then go to rinse in the water.

Marcia

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danalka    0

Hi Marcia or anyone, can you advice me on the obvara brew? The mixture I prepared (by this wide spread recipe) ferments the first day and then it stoped even if I stirred and fed it with more flower or yeast or beer. Does it mean the brew is ready or does it mean it didn't ferment enough and would not work? Anyone has similar experience? Please help. Thank you, Dana

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