Can float glass be tack fused with Bullseye glass

[Flowers]

Hi  is it possible to tack fuse float glass onto Bullseye glass or would it still be incompatible I just wondered if the same problems would happen if the float glass is tack fused rather then fully fused into the glass.
Thank you

[flame n fuse]

You could try it with some transparent bullseye and inspect for stress using a computer screen and a polarizing filter.

[Flowers]

That is a very good idea I like the idea of using a computer screen and the polarising filter would it brave like a light box?

[Enchanted Cobwebs]

My hubby is a fuser, he says no, just wont work

[flame n fuse]

   I don't think a light box would work - the computer screen emits polarised light and you hold up the object you are testing in front of it, then hold a polarizing filter (sunglasses / camera filter)   in front and rotate and you can see the stress. I can't find a good link online, but this one shows how to do it with a phone screen     http://www.davebross.com/GlassTech/polariscope.html

[Fluffstar]

My gut instinct says no, it won't work.  

However if you want to test for stresses - I use two of these:
http://www.ebay.co.uk/itm/Polarising-Polarised-Polarizer-Filter-Film-Gel-Sheet-Science-50x100mm-2lee-d-/262826326296?hash=item3d31ab7918:g:jmAAAOSwqu9VHDZ1

on top of a light box/light source.  A window would work fine if you don't have a light box.  Just hold one film behind and one in front, and rotate the top one 90 degrees.

Stress looks like this:



That's two chips of 104 fused to tekta - they cracked about three days after.  Compare to:



There are two chips under there, you just can't see 'em!  That's bullseye on top of bullseye.


[edited to add BE pic]

[Dietmar]

Float has a COE of 82. Bullseye has 90. That is a diference of about ten percent.

Tackfusing means the glass is just sticking togeather and the contact surface has still undercuts. These undercuts will be the starting point of the cracks. If you are lucky, you can see the finished work when opening the kiln, but expect the diferent COEs separated and at unintented places in the kiln.

Fazit: Unless you want to create an "implosion effect" stay within only one COE.