annie
Junior Member
Posts: 55
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Post by annie on Nov 9, 2016 8:34:01 GMT -6
Hi all, I'm hoping for some practical advice to improve glazing my rims on mugs, bowls, pitchers, etc. I thought I had this figured out but my success ratio is not improving.
I'm getting pin-holing still where the crystalline glaze overlaps the liner--not all over but in spots. (I have a twenty minute hold at top temp). I thought the problem was being caused by a glaze thickness issue (too thick liner) from dipping the rims after I'd glazed the insides of the pots (or the reverse order) so I've tried fettling, or dipping the piece in one go then sponging off excess on exterior where I use my crystalline glazes. I tend to leave about 3-5mm of liner down the outside of the pieces then put crystalline over 2-3mm of this.)
I don't think it's a glaze composition problem but glazing procedures with crystalline.
Maybe I don't need to put liner on the rims or over the rims? What do others do?
Really welcome all advice/suggestions.
--Annie
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bbucky
New Member
Married
Posts: 36
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Post by bbucky on Nov 9, 2016 22:02:04 GMT -6
Hi Annie, You could try a little lithium carb, I've found if it doesn't smooth things out on the lips, it could make you just not feel so bad about it anyway. Seriously though, doing a few tests adding a little flux to a liner glaze could solve it, and it can't really hurt much, after all it is a liner. Lithium brightens too. bbucky
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annie
Junior Member
Posts: 55
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Post by annie on Nov 10, 2016 2:42:15 GMT -6
Hi Bill, Thanks for this suggestion of lithium. It made me smile.
You're thinking my liner is too stiff then. It may well be as I added 3grams silica awhile back to stop the crazing entirely on my clay body. I also must learn to watch the cones bend. This load was packed more lightly with less kiln furniture and shelves now that my pieces are taller and the cones show I didn't get enough heat work throughout this kiln load too. They're underfired at the top -- which could be the real problem vs application. I looked at precious pieces (before my contactor was replaced making my kiln more efficient) and no pinholes on the liner.
Do you think adding 0.2 lithium would still be beneficial? And not reintroduce the crazing? (My kiln varies a half cone from top to bottom.)
Thank you! --Annie
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annie
Junior Member
Posts: 55
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Post by annie on Nov 25, 2016 5:54:52 GMT -6
Just want to thank those kind souls who emailed me with suggestions. More heatwork did the trick. With my new contactor, switches and elements my kiln was just far too efficient and I was underfiring in upper half of kiln.
Love you guys! --Annie
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