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Post by hollymckeen on Jul 10, 2015 10:15:32 GMT -6
Hey all! So on the old forum, there was a recent thread by Arnie on strike firing, and I tried to add my intel & experience on the topic, but it simply wouldn't go in, and I lost it all... So, here is what I can remember to add to that info. Yes, re the bubbly glaze pic of Phil's on a Childered piece - my experience is that once a piece has been in the vinegar or whatever, it will NOT like a strike fire. Don't bother it will be yuch. After experimenting with temp a lot, I came to strike lower than discussed - closer to 018, to get the results I want, and I do go up and back down very slow. And my experience is that there needs to be at least 4% titanium in any piece for striking to have much effect - as is probably the case in your layering, Arnie, with rutile of titanium in the layers. Sometimes the best results come in the layers with some non-titanium and titanium glazes - where the actual % varies - but still, when there is a total of upward of 4% the sesults are most noticeable. Cobalt is the addition that will, added to the ti, give the most effect and it only takes a whisper. And yes, for all you precise minded men out there - a "Whisper" is in fact an accurate measurement. Ginny and I use it with great precision. (i.e. "a hair more than a whisper"...) Other oxides, even in combination with the ti, give me nothing - like mang - does nothing in my experience. Add silver nitrate into the equation, and things change a lot... Hope that's helpful to some... there's a load of testing and experimenting to get to those few conclusions... Here's an old one... this was just white and brown before the strike:
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joerg
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website: www.crystalsforever.com
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Post by joerg on Jul 10, 2015 14:11:16 GMT -6
just to confirm one comment from Holly.... twice already... an etched piece (etched with diluted HCL ) , which still I didn't like ... and refired.... exploded in the kiln.... lots of small clay particles on all the other pieces...the only way, to refire an etched piece is to do another very slow bisque first....
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Post by Arnie Benton on Jul 10, 2015 16:21:29 GMT -6
Hi Holly - I'm glad that you're back.
Here are 2 struck pieces with the exact same glazes - Fe Mn Ti on the bottom and Cu Co Fe Ti on top - on the left the ratio is 1 to 2 and on the right it is 2 to 1.
However my major contribution is to demonstrate that the font size can be increased. Do you have access to change the default font size? That would be wonderful for those of us who are visually challenged. The striking temp range comes from my post fire reduction program - to control for that so the only difference is the propane. I will try your lower number, around 1300, probably with an hour hold. I've had pieces split in half after striking, so I also go up and down very slowly from 1000 to 1100 and down from 600 to 400. Hi Joerg - exploding pieces is a scary image.
Arnie
AHA! The font size can't be increased. Even more reason to try to get the default size increased!
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Kuba
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SztukKilka in Old Formu
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Post by Kuba on Jul 11, 2015 3:11:55 GMT -6
I fired etched pieces and without any problems. This one was etched for one day in strong HCL and after that I fired it in 740C (1364F) with 1,5h hold
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Kuba
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Post by Kuba on Jul 11, 2015 3:15:44 GMT -6
And the same story with this one:
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Post by Arnie Benton on Jul 11, 2015 9:28:30 GMT -6
Hi Kuba - The first piece seems to have the rough, grainy change in the ground that I've gotten. The second vase is harder for me to see. Is it more matte? Maybe we need to put together a list of the glaze ingredients to figure out what's causing different reactions to striking after etching. Arnie
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Kuba
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SztukKilka in Old Formu
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Post by Kuba on Jul 11, 2015 12:53:52 GMT -6
Hi Arnie, First one had cracks all over it. And during striking those cracks melted and gave very interesting surface (I looks like delicate spider web all over the pot). It is simple formula 3/3/3 - Copper, Mangan, IOR. Second vase just change the crystals color to black. Another simple formula 3/3/3 - Copper Red, Copper Black, Dolomite Regards Kuba
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joerg
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website: www.crystalsforever.com
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Post by joerg on Jul 11, 2015 13:47:39 GMT -6
I fired etched pieces and without any problems. This one was etched for one day in strong HCL and after that I fired it in 740C (1364F) with 1,5h hold Jakub: I refired completely... i.e.1280° top...
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Post by billpowellart on Jul 23, 2015 22:15:02 GMT -6
Hi Guys, I've noted that when you have etched a piece in HCL and then wash it of and dry it there is a rainbow film left on it that takes a bit of rubbing off. I have had good results with reduced,etched pieces and am wondering [ for the chemists out there] if the film is a thin coat of Metal Chloride that can result in lustre finishes? Any one seen this film I have seen ? Cheers
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Post by tileman2 on Jul 24, 2015 17:04:33 GMT -6
Bill:
I do not have an answer for you other than experience with HCL in the construction industry. HCL is one of the few acids that does not lose potency when exposed to air ( pulled out of the wash to dry.) When we etched stone, concrete, etc: if we did not neutralize the acid with lime or some other alkali; it would keep etching until effervescence appeared. A film that was milky white, that sometimes had a pearl-like appearance. We all know HCL will attack metal oxides; that is the whole point to begin with. As an experiment ( will call it that for now), try rinsing in an alkai bath to neutralize the HCL. If you have lime, that is cheap, or a bit of feldspar, perhaps whiting: all relatively cheap. Would think a few tablespoons in a gallon of water would do the trick. Give it a shot.
Tom
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Post by sherri on Jul 24, 2015 21:33:35 GMT -6
When I did soldering and casting in jewelry making, after soldering, we would place the piece in Sparex pickle - the active ingredient which is sodium bisulphate - to clean the piece and then have the neutralize the acid by placing it in a bath of baking soda - such a nice, cheap neutralizer. I was surprised that in the discussions of using aggressive leachants, a neutralizer has not been mentioned in the posts that I've seen. We were always told that if you didn't neutralize the acid, it would continue to eat away the metal.
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Post by Arnie Benton on Aug 8, 2015 17:45:29 GMT -6
Here are some more striking results - or results from striking - I'm beginning to get more precise about what it takes for striking to perform its magic. Here's a before and after - This plate has layered glazes - A 413 glaze with Ni1 Cu1 Fe1 Ti2 on the bottom and another 413 glaze with Ru4 Cu1 Co.1 on top, one coat of the Ni glaze and 2 coats of the Ru glaze. This piece also has an engobe with 5% Li and 5% Whiting applied before the bisque firing - but I don't think it's a necessary piece of the puzzle. Here's another - Before After This one has a 413 glaze with Fe2 Co.2 Ti4 on the bottom and a 413 glaze with Cu1 Co.5 Ti2 on the top, ratio 1 to 3. Engobe has 5% Ti. As Holly described, all the pieces that change dramatically with striking have Co and a lot of Ti. Without an engobe I've gotten good results also with Fe2 Mn1 Ti4 on the bottom and an Cu1 Co.5 Fe.2 Ti2 glaze on top, ratio 1 to 3. I have no idea how this works on vertical surfaces. I hope someone tries and lets us know. Arnie
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Post by tileman2 on Aug 8, 2015 21:30:01 GMT -6
Wonder what it is about TiO2 that makes it so reactive? Hmm, must turn aside to investigate. On tile, excess TiO2 overpopulates. Anyone ever mess with frit 3195 for cone 6?
Tom
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Kuba
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Post by Kuba on Aug 9, 2015 1:34:20 GMT -6
Second one is hypnotizing. Keep going Arnie!
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Post by tileman2 on Aug 9, 2015 18:21:03 GMT -6
Question:
When referencing TiO2: are we talking naturally occurring mineral, or chemically processed? Are we talking rutile or ilmenite; or white processed powder forms?
Tom
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