Two strange developments when I fused

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J. Wang
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Joined: Fri May 24, 2013 12:49 pm

Two strange developments when I fused

Post by J. Wang »

Hello, I am new to this board. I have an retail art studio and boutique in the San Francisco area. One of the activities I offer is a drop-in fused glass studio. I opened about a month ago and business has been brisk. I've done many, many firings with no problems until I yesterday. One customer made a pocket vase. When I took the fully fused piece out of the kiln, I discovered that the back of the piece had split creating a long skinny vertical hole (the glass was not split to begin with). I'm thinking there must have been a defect in the glass. I'd post a picture of it, but I don't know if I can on this board. I'm thinking of re-fusing it with a matching piece under it. I'd appreciate some expert opinions on why this happened and if re-fusing is the solution. I use COE96 glass.

The second unexpected result happened to a little plate another customer made. She'd used fine frit sprinkled on top of glue to write out the word TEA, each letter a different color frit. The glass beneath it was a cobalt blue Uroboros wavy semi-transparent. The frit colors were bright and showed nicely before firing. After the full fuse though, the frit fired so pale and lightly into the blue under glass that the letters can barely be seen. My question is: if she sprinkled the frit over the letters again and I did a tack fuse, would the letters come out brighter? Or should I full fused it again?

Thank you!
J. Wang
Alameda, CA
Brad Walker
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Re: Two strange developments when I fused

Post by Brad Walker »

The crack in the fiber piece isn't due to defective glass, it's because the fiber paper insulated the glass in certain areas and caused a crack which healed during the firing, leaving the hole. If you post your firing schedule, we may be able to suggest a better schedule that would be less liable to cause the break. Letting us know the thickness of the fiber paper used would also help.

Anytime you fire frit on a dark background, the colors won't be that noticeable after the firing unless they're a very light color. If you add more frit and do a tack fuse the end result will be more readable. But even then, you have to make sure the colors will show up against the cobalt blue. A tack fuse will generally give you a better result than a full fuse in this kind of firing.
tbach
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Re: Two strange developments when I fused

Post by tbach »

I have experienced the "disappearing color" factor as well. Found that if I sift a fairly thin (but even) layer of opaque white powder before sifting the lighter colors, the colors will show up very well on dark glass. To avoid confusion, I will add that if you are using stencils or a silkscreen, the opaque white has to be sifted with the same stencil or shape . . . color applied afterwards has to be registered carefully so that none of the white shows, unless you like a white shadow.
JestersBaubles
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Re: Two strange developments when I fused

Post by JestersBaubles »

Another thing to add is that (as far as I know, and at least with System 96...) all frit is transparent unless it is specifically marked as opal. Opal frit is going to give you a much stronger color than transparent.

Dana
Brad Walker
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Re: Two strange developments when I fused

Post by Brad Walker »

JestersBaubles wrote:Another thing to add is that (as far as I know, and at least with System 96...) all frit is transparent unless it is specifically marked as opal. Opal frit is going to give you a much stronger color than transparent.
That's a really good point. Transparent frit over a dark color will usually look fine before firing, but can virtually disappear after firing.
Laurie Spray
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Re: Two strange developments when I fused

Post by Laurie Spray »

tbach.....have you tried mixing the white powder with your color before stenciling?
Laurie Spray

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J. Wang
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Re: Two strange developments when I fused

Post by J. Wang »

Thanks to everyone who responded. The disappearing frit is an annoyance. I re-fired with opal frit and two colors came out better, but the green pretty much disappeared again. I'll contact the customer and ask her to use brighter frit, and I'll tack fuse. The repair attempt on the hole didn't come out well either. The hole stretched an important part of her design so I will just invite her to remake the piece. I've fired many, many pocket vases before with no problems, so I think this must have been a fluke.

Question for future posts: how do I upload photos to the board (for the next time something strange happens)?

Thanks!
J. Wang
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Re: Two strange developments when I fused

Post by Brad Walker »

J. Wang wrote:Question for future posts: how do I upload photos to the board (for the next time something strange happens)?
To upload a photo:

The photo must be 256k or smaller, jpg format.

When you post, you'll see a tab labelled "Upload Attachment" beneath the box in which you type you post. Click on the tab and you'll be able to browse your computer, find the file, and upload it to be attached to your post.
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