glass shrinkage

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Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

glass shrinkage

Post by Luiza »

Hi
I have to fuse one layer of glass - 3mm. I know that there will be some shrinkage. I want that the final piece to be 8.3X7.5 in. Is there any formula that I can use to calculate the size of the original glass? Is it linear, or the shrinkade depends upon the area?
Thanks
Luiza
Bert Weiss
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Location: Chatham NH
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Re: glass shrinkage

Post by Bert Weiss »

Luiza wrote:Hi
I have to fuse one layer of glass - 3mm. I know that there will be some shrinkage. I want that the final piece to be 8.3X7.5 in. Is there any formula that I can use to calculate the size of the original glass? Is it linear, or the shrinkade depends upon the area?
Thanks
Luiza
Test
Bert

Bert Weiss Art Glass*
http://www.customartglass.com
Furniture Lighting Sculpture Tableware
Architectural Commissions
Brock
Posts: 1519
Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Re: glass shrinkage

Post by Brock »

Luiza wrote:Hi
I have to fuse one layer of glass - 3mm. I know that there will be some shrinkage. I want that the final piece to be 8.3X7.5 in. Is there any formula that I can use to calculate the size of the original glass? Is it linear, or the shrinkade depends upon the area?
Thanks
Luiza
What do you mean, "fuse one layer of glass "? You should be able to fire polish a pices of glass that size without it trying to achieve equilibrium thickness. Brock
My memory is so good, I can't remember the last time I forgot something . . .
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

Well, I won´t really fuse it, but I want to texturize it with some forms done from fiber paper, and I´ve done lots of tests and I found that it has to stay 10 min soak at 1470 F, to be perfect.
Thanks
Luiza
Brock
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Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Post by Brock »

Okay. See Bert's post. Brock
My memory is so good, I can't remember the last time I forgot something . . .
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

That´s not fair :lol:
At least it is linear???? If I test one I can apply for any areas????
Please, say YES
Luiza
Brock
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Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Post by Brock »

I don't know. The longer you're hot the more it'll pull in. Why can't you make it out of 6 mil glass? The tiles look better. Brock
My memory is so good, I can't remember the last time I forgot something . . .
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

It´s not a tile. I´m doing 18 pieces of glass to decorate a bathroom door, and the idea is to have diferent textures. So I decided to texturize one layer, and I´ll put it together with another blasted or "sponge painted", so that it has a good appearance from both sides, and will not be transparent.(Some privacy...). They will be at a door of a bathroom of a person that bought my first sink. I´m so proud!!!!!! And I´m also so gratefull to Bert and Carol. Good friends, both of you...
That´s why I can´t use 2 layers. Any idea to make things easier?
Luiza
Last edited by Luiza on Wed Jun 25, 2003 10:45 pm, edited 1 time in total.
Brock
Posts: 1519
Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Post by Brock »

Luiza wrote:It´s not a tile. I´m doing 18 pieces of glass to decorate a bathroom door, and the idea is to have diferent textures. So I decided to texturize one layer, and I´ll put it together with another blasted or "sponge painted", so that it has a good appearance from both sides, and will not be transparent.(Some privacy...). They will be at a door of a bathroom of a person that bought my first sink. I´m so poud!!!!!! And I´m also so gratefull to Bert and Carol. Good friends, both of you...
That´s why I can´t use 2 layers. Any idea to make things easier?
Luiza
Are these going into a matrix, lead, or wooden mullions? How are the two tiles being assembled? Do you have access to a tile saw or a wet belt sander? Brock
My memory is so good, I can't remember the last time I forgot something . . .
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

It´s a wooden door, six lines with three columns of glass.
I have a sander, but not a wet one, and no, I don´t have a tile saw. It was a long discussion, the tile saws here are 11000rpm...
I was thinking that I could glue the two tiles with UV glue...Good idea?
Luiza
Brock
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Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Post by Brock »

I'd go with GE silicone, the UV glues require a very smooth fit between the layers. Silicone is much more forgiving. You could also use the silicone as the bedding compound in the mullions. Now, as to the size.

Test.

Brock
My memory is so good, I can't remember the last time I forgot something . . .
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

Thanks a lot. Silicone will be much better!!!!!!
Ok, ok, I´ll do the tests :cry:
Luiza
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

can´t sleep - now I´m curious

Post by Luiza »

Brock
What would you suggest if I had a wet belt sander and a tile saw????
Luiza
Brock
Posts: 1519
Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Re: can´t sleep - now I´m curious

Post by Brock »

Luiza wrote:Brock
What would you suggest if I had a wet belt sander and a tile saw????
Luiza
I wouldn't be worried about shrinkage, I'd make the tiles oversize and cut them down to the exact size you require. Brock
My memory is so good, I can't remember the last time I forgot something . . .
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Re: can´t sleep - now I´m curious

Post by Luiza »

Brock wrote: I wouldn't be worried about shrinkage, I'd make the tiles oversize and cut them down to the exact size you require. Brock
I hate an obvious answer to a silly question. :oops: I deserved it :lol:
Thanks for your help, Brock, I´ll begining my test NOW.
Luiza
Bert Weiss
Posts: 2339
Joined: Tue Mar 11, 2003 12:06 am
Location: Chatham NH
Contact:

Post by Bert Weiss »

Luiza wrote:Well, I won´t really fuse it, but I want to texturize it with some forms done from fiber paper, and I´ve done lots of tests and I found that it has to stay 10 min soak at 1470 F, to be perfect.
Thanks
Luiza
Luiza

I have done plenty of work around 1470 for 10 minutes. I now like 1365 for 1 hour. As long as devit is not an issue, this schedule yields a nicer surface on the bottom.

I guess that the size change will be different for various thicknesses. I find that the size doesn't change much for me. Sometimes not at all.
Bert

Bert Weiss Art Glass*
http://www.customartglass.com
Furniture Lighting Sculpture Tableware
Architectural Commissions
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

Bert Weiss wrote:
Luiza

I have done plenty of work around 1470 for 10 minutes. I now like 1365 for 1 hour. As long as devit is not an issue, this schedule yields a nicer surface on the bottom.

I guess that the size change will be different for various thicknesses. I find that the size doesn't change much for me. Sometimes not at all.
I´ve done some tests today, and I found that my 3mm layer - 21X19 cm -
was reduced to 20.3X18.2 cm. The worst are the edges - the layer is not a perfect rectangle anymore, it has 4 ugly edges.
I´ll try 1365 for 1 hour tomorow.
Thanks
Luiza
Bert Weiss
Posts: 2339
Joined: Tue Mar 11, 2003 12:06 am
Location: Chatham NH
Contact:

Post by Bert Weiss »

Luiza wrote:
Bert Weiss wrote:
Luiza

I have done plenty of work around 1470 for 10 minutes. I now like 1365 for 1 hour. As long as devit is not an issue, this schedule yields a nicer surface on the bottom.

I guess that the size change will be different for various thicknesses. I find that the size doesn't change much for me. Sometimes not at all.
I´ve done some tests today, and I found that my 3mm layer - 21X19 cm -
was reduced to 20.3X18.2 cm. The worst are the edges - the layer is not a perfect rectangle anymore, it has 4 ugly edges.
I´ll try 1365 for 1 hour tomorow.
Thanks
Luiza
Luiza

It sounds to me like you have a few alternatives. You can make the piece 1-2" larger on all sides and cut it down with a glass cutter. You can try 6 mm glass or 10mm. Or maybe the lower temp will have a different effect.

It is interesting to me that you have the shrinkage problem. I guess that the factor of glass wanting to be 6mm holds close to true all around.
Bert

Bert Weiss Art Glass*
http://www.customartglass.com
Furniture Lighting Sculpture Tableware
Architectural Commissions
Luiza
Posts: 81
Joined: Sun Mar 09, 2003 4:50 pm
Location: Rio de Janeiro / Brazil

Post by Luiza »

Bert Weiss wrote: Luiza

It sounds to me like you have a few alternatives. You can make the piece 1-2" larger on all sides and cut it down with a glass cutter. You can try 6 mm glass or 10mm. Or maybe the lower temp will have a different effect.

It is interesting to me that you have the shrinkage problem. I guess that the factor of glass wanting to be 6mm holds close to true all around.
Hi Bert
I was thinking of making a test - let a 3mm layer stay for some hours at 1470 F - maybe it becomes a 6 mm layer :lol:
I can´t use any glass thicker than 6 mm- that is the space I have -, and as I need 2 separeted layers, the thicker I can fire is 3 mm.
I tested the 1 hour 1365 F today. The kiln was still hot, so I could´n measure it. Now I´ll have to wait till monday...
Unfortunately I don´t have a tile saw, so I´ll have to manage another solution.
I imagine that you don´t have a faintest idea of how dificult is to work with glass or any other art or craft here. If some of you have interest I ´ll be happy to make a "brief" of this wonderfull and absolutely non conventional country in Spab´s place...There are very good things too - it´s not bad at all :D
Thanks again
Luiza
Brock
Posts: 1519
Joined: Mon Mar 10, 2003 1:32 pm
Location: Vancouver, B.C.

Post by Brock »

I'd love to hear your "brief" Luiza. Brock
My memory is so good, I can't remember the last time I forgot something . . .
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