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Tack fusing temp. for frits

Posted: Sat Jul 20, 2019 3:57 am
by Havi
Hello Dear friends,
Hope you are ALL well, wherever you are....
I am planning to create some glass pieces that will get into bigger pieces, not necessarily glass.
I would like to tack fuse frit to an extent that one could still see the glass grains [this is imperative].
I would like to consider all kinds of frits -
01 - the thinnest [ignoring real powder]
02 -
03 -
What temp. should I reach? F or C - I can translate.
Should I have a bubble soak???
is there an estimate how much will it shrink?

Would be grateful for any response, even if it is partial - - -
Many thanks in advance,
Havi

Re: Tack fusing temp. for frits

Posted: Sun Jul 21, 2019 8:53 am
by Brad Walker
Because kilns are so variable and your desired look is so specific, the best option is to do some small scale testing to see what works for you in your process. Use a base glass and put frit of various sizes on it, then fire to different temperatures to see what you like. It's a bit more complicated because different colors behave differently.

Obviously, the larger sizes of frit will soften the least, so the temperature that works best for coarse will be too high for fine. And the glass will shrink 1/4 to 1/2, the smaller the grains the more it will shrink, and the higher the temperature the more it will shrink.

Temperature-wise, grains will stick together starting at around 1325 to 1350F (718 to 732C) and will pretty much no longer be grainy by the time you get above 1400 to 1425F (760 to 774C). So the lower temperature will give you the most graininess and the higher the least.

A bubble soak adds more heat, so if you include one your top temperatures will be different (lower).

But the bottom line is that this is really something you'll have to test for yourself, only you know the exact look you're after.

Re: Tack fusing temp. for frits

Posted: Sun Jul 21, 2019 5:19 pm
by Havi
Thanks, Brad
I want only a thin layer of tack fused glass [without another layer underneath it]
It is supposed to be glued to a fragile thin hand-made paper which I make. - Therefore must be light.
It is important for me that you mentioned the effect of the size of the frit, and I shall check both.

By the way, there is a Bullseye sheet of glass which is called heat and glass, where I found that there is an option of firing at 690C degrees - perhaps this might be good for the thinner frit. I guess I shall try both, but directly on the shelf...

Thanks again,

Havi

Re: Tack fusing temp. for frits

Posted: Wed Jul 24, 2019 9:31 pm
by Buttercup
Hi Havi, I've just seen this thread and have done just what I believe you are looking for, frit melted to stick to itself, nothing underneath. It was used as flower centres. If you haven't found the answer by experimenting let me know and I'll look for my notes.