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Using "Crystal Clear" powder

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Using "Crystal Clear" powder

Postby crishna_simmons » Sat Nov 24, 2012 3:35 am

Hi,

New here, with a technical question. I don't have my own kiln, and use the one at my adult education class, so I don't have firing details.

Recently used crystal clear glass powder for the first time to "fill in" gaps on a chunky frit piece and when it came out of the kiln, the powder was not clear but a sort of transparent milky colour instead. That piece was tack fused. So then I tried just sieving some in different thicknesses on clear glass, (over a single blue stringer for colour contrast) to test it and did one on full fuse, and one on tack fuse with a similar result. Looks clear(ish) if there is a strong light behind it, but otherwise looks milky.

Were my expectations unrealistic - does clear powder always perform like this? (apologies for the bad photo!)
Image
failure with powder by Kikishua, on Flickr
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Re: Using "Crystal Clear" powder

Postby marykaynitchie » Sat Nov 24, 2012 3:41 pm

Hi Crishna,

Powdered transparent glasses that are fused or cast in thicknesses of about 2-3mm deep or more will trap bubbles that give the glass a milky or opalescent appearance. This is due to trapping lots of very tiny bubbles. Using frits of larger sizes (retained on screens with larger mesh sizes) will allow fewer bubbles and result in more transparency. There is more about this at http://www.bullseyeglass.com/methods-id ... nting.html

Mary Kay
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Bullseye Glass Co.

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Re: Using "Crystal Clear" powder

Postby noah9926 » Fri Jul 06, 2018 7:48 am

I have the same issue. When I mixed the "clear" with other colors it turned them milky too. It was disappointing. I have been experimenting to get a clear look so crushed some of my studio blowing glass - it turns out perfectly clear. If the powder always turns out milky I think there should be a note added to say that just so people aren't disappointed. I ruined several pieces assuming it was actually going to be clear. I will try the larger frit sizes to see how it works, but doubt I will order the powder again.
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Re: Using "Crystal Clear" powder

Postby marykaynitchie » Tue Jul 17, 2018 2:27 pm

If you are filling in actual gaps or holes in the surface of your piece, little pieces of frit work better than powder. Try to use the fewest and the largest pieces that will fit, to minimize bubble trapping.

Mary Kay
Mary Kay Nitchie
Bullseye Glass Co.

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