Glaze Bubbling

Deleted
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Glaze Bubbling Jul 20, 2017 18:24:46 GMT -6

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Post by Deleted on Jul 20, 2017 18:24:46 GMT -6

Hello,

I had a really nice, tall vase that turned out some beautiful aqua/green (copper carbonate) crystals. I wanted to try to remedy something (actually forgot what it was), so I took it back up to cone 04 and it came out with a lot of small (one to three mm) bubbles in the glaze. It was probably the nicest piece I've done to date, so I wasn't happy.

Does anyone have any ideas what would cause bubbling at 04 when it was already fired to 9, with all the attendant holds necessary for growing the crystals?

Thanks,

Gabriel

mohawkpiper Administrator Posts: 274	Glaze Bubbling Jul 21, 2017 10:02:02 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by mohawkpiper on Jul 21, 2017 10:02:02 GMT -6 if you ever figure it out id love to know. ive gotten this on post fire reduction occassionally. usually cooper pieces.
	animator by day, potter by night

Deleted Deleted Member Posts: 0	Glaze Bubbling Jul 21, 2017 10:06:55 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by Deleted on Jul 21, 2017 10:06:55 GMT -6 Well, Greg, looks like the copper might be the common denominator in this puzzle. I was wondering what re-firing it to cone 6 would do toward flattening them out. Probably melt the crystals.

Arnie Benton
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Posts: 204

Glaze Bubbling Jul 21, 2017 11:51:02 GMT -6

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Post by Arnie Benton on Jul 21, 2017 11:51:02 GMT -6

I can add that doing reduction above about 1750 causes the Cu to bubble out of the glaze.
When I've done striking in that range the crystals change dramatically - I'm surprised that didn't happen with your piece. If you refire to cone 6 you'll melt the crystals and if you do some crystal growing holds you'll get a mass of small crystals.

Arnie

Deleted Deleted Member Posts: 0	Glaze Bubbling Jul 21, 2017 13:01:12 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by Deleted on Jul 21, 2017 13:01:12 GMT -6 Thanks Arnie. I may just try to create some crystals at cone 6 rather than just retire the piece to the scrap heap. I assume you are referring to doing those holds at cone six?

mohawkpiper Administrator Posts: 274	Glaze Bubbling Jul 21, 2017 15:57:51 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by mohawkpiper on Jul 21, 2017 15:57:51 GMT -6 i reduce copper (initial firing) waaaay over 1750 F and dont get any bubbling. not even once. ive only gotten bubbling on post fire reduction between 1350 and 1500 and only sometimes.
	Last Edit: Jul 21, 2017 15:59:17 GMT -6 by mohawkpiper animator by day, potter by night

mohawkpiper Administrator Posts: 274	Glaze Bubbling Jul 21, 2017 16:00:38 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by mohawkpiper on Jul 21, 2017 16:00:38 GMT -6 ive gotten bubbling once or twice striking titanium and iron
	Last Edit: Jul 21, 2017 16:01:21 GMT -6 by mohawkpiper animator by day, potter by night

Deleted Deleted Member Posts: 0	Glaze Bubbling Jul 21, 2017 16:03:05 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by Deleted on Jul 21, 2017 16:03:05 GMT -6 I can assure you that my skills in crystalline glazing are sufficiently primitive that I haven't even considered any reduction firing.

Post by Deleted on Jul 20, 2017 18:24:46 GMT -6

Post by mohawkpiper on Jul 21, 2017 10:02:02 GMT -6

Post by Deleted on Jul 21, 2017 10:06:55 GMT -6

Post by Arnie Benton on Jul 21, 2017 11:51:02 GMT -6

Post by Deleted on Jul 21, 2017 13:01:12 GMT -6

Post by mohawkpiper on Jul 21, 2017 15:57:51 GMT -6

Post by mohawkpiper on Jul 21, 2017 16:00:38 GMT -6

Post by Deleted on Jul 21, 2017 16:03:05 GMT -6