gczop
Full Member
Posts: 202
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Post by gczop on Jan 30, 2016 10:35:05 GMT -6
 This a self reduced copper red after Sanders' book Glazes for Special Effects. The operative ingredients are 0.3% Silicon Carbide, 0.4% CuCO3 and 0.7% Tin Oxide. Fired in an electric kiln in an oxidizing atmosphere cone ten flat. The classic Chinese copper red glazes are different, separating into three layers during firing,the middle one containing the reduced copper. See Nigel Wood's book Chinese Glazes for details. |
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joerg
New Member
website: www.crystalsforever.com
Posts: 49
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Post by joerg on Jan 30, 2016 15:48:38 GMT -6
This a self reduced copper red after Sanders' book Glazes for Special Effects.
The operative ingredients are 0.3% Silicon Carbide, 0.4% CuCO3 and 0.7% Tin Oxide.
Fired in an electric kiln in an oxidizing atmosphere cone ten flat. Hi Gordon, and thanks! Which grain size has your Silicon Carbide? 200 - 400 - 600? I only get 200 in Spain and always thought that < 500 doesn't work... hasta la vista! Jörg |
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Post by tileman2 on Jan 30, 2016 15:54:17 GMT -6
Gordon: Very nice piece first off. Jim posted a paper on various combinations to produce reds: tin oxide was among them. I would have never believed that, but I need to change my mind apparently. Question: would this fall into the Avertine glaze category?
Tom
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gczop
Full Member
Posts: 202
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Post by gczop on Jan 30, 2016 16:28:20 GMT -6
Hi guys,
The silicon carbide is from Laguna which info says 400 grit.
The glaze does not have the character of aventurine glazes.
The base is simple, custer feldspar, silica, and equal parts of whiting and 3110 frit.
Gordon
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Post by jfox on Jan 31, 2016 11:05:32 GMT -6
I could never get it to work without pin holing,it releases CO2 at high temperature but i have some super fine silicon carbide now think ill try again
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Post by jfox on Jan 31, 2016 11:08:26 GMT -6
Tin promotes copper reds and Barium helps too
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Post by tileman2 on Jan 31, 2016 16:06:29 GMT -6
Jim:
I knew about the barium and knew (some, very little) about the silicon carbide. Just hard to get my head around tin oxide knowing how tin acts as a colorant. Going to have to accept it however, the proof is in Gordons piece. Read a bit about silicon carbide: classified as a reduction agent- so that explains alot. Ordered a lb of 400 mesh carbide yesterday. I am still curious if cadmium would deepen the red color- will have to experiment with that as well.
Tom
Arnie- not seen you post in awhile- doing okay?
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Guru
New Member
Posts: 11
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Post by Guru on Jan 15, 2018 2:06:27 GMT -6
This a self reduced copper red after Sanders' book Glazes for Special Effects. The operative ingredients are 0.3% Silicon Carbide, 0.4% CuCO3 and 0.7% Tin Oxide. Fired in an electric kiln in an oxidizing atmosphere cone ten flat. The classic Chinese copper red glazes are different, separating into three layers during firing,the middle one containing the reduced copper. See Nigel Wood's book Chinese Glazes for details. |
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Guru
New Member
Posts: 11
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Post by Guru on Jan 15, 2018 2:12:46 GMT -6
Hi folks!
Did someone try to do a false (chemical) reduction using Silicon carbide with crystalline glazes?
Thanks!
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Post by mohawkpiper on Jan 16, 2018 15:30:21 GMT -6
Hi folks! Did someone try to do a false (chemical) reduction using Silicon carbide with crystalline glazes? Thanks! I have tried I believe... but not very hard. It was a long time ago... I don't remember being very successful. I know i tried 200 grit (which was horrible) and now have like 600 or something, but can't remember if I used it for crystalline. Perhaps later tonight I can find some time to dig up my notes and share. G |
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Post by mohawkpiper on Jan 16, 2018 15:31:29 GMT -6
and VERY NICE! Gordon. great job  |
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Guru
New Member
Posts: 11
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Post by Guru on Jan 17, 2018 2:33:48 GMT -6
Hi folks! Did someone try to do a false (chemical) reduction using Silicon carbide with crystalline glazes? Thanks! I have tried I believe... but not very hard. It was a long time ago... I don't remember being very successful. I know i tried 200 grit (which was horrible) and now have like 600 or something, but can't remember if I used it for crystalline. Perhaps later tonight I can find some time to dig up my notes and share. G |
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Guru
New Member
Posts: 11
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Post by Guru on Jan 17, 2018 2:51:14 GMT -6
Thanks moha!
I'll try with 800 and 1000 grit in a ongoing experiment about Al2O3 boundary (via UMF and Stull chart) in CG.
Probably will not be successful reduction because of a long cooling period (SIC can "evaporate"), but it's worth to try.
I'll post the results of the experiment and here.
Cheers!
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paul
Junior Member
Posts: 51
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Post by paul on Jan 17, 2018 12:51:08 GMT -6
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Post by mohawkpiper on Jan 17, 2018 23:42:38 GMT -6
Guru... this is all I could find... A few of stuff like this...  it was actually 60 grit silicon carbide... not 200 grit. 5%. Pretty nasty. I later bought 400 grit... but I cant find anything in any of my notes about trying it in crystalline... so I either never got to it or intended to use it in non crystalline glazes... the non crystalline stuff I never really note very well... I'm not sure I ever tried it. |
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