glass is breaking

[AJK25]

I own a business that makes cabinet hardware. The pieces of hardware are made with glass and metal. For a new hardware design, I am getting some pieces of glass that are breaking during shipment. They are predominantly clear glass. I am using one 6mm layer of Bullseye glass. Photo of the pull is attached. Does anybody have any idea why the glass is breaking? The pieces that I make with white and black glass are not breaking. With the white and black glass, I use two layers of 3mm glass that are fused together. With the clear, it is only one layer of 6mm clear. Perhaps when the glass is fused together, it becomes stronger?

I glue the glass to the metal to make the final piece.

I hope somebody can help.

Thanks,

Drew

[jim simmons]

I am confused.
Why are you using BE clear?
I would get to a window repair shop and buy 6 mm float glass.
The reason is 2 fold.
1. Cost
2. BE glass is not fully annealed when it comes out of the leahr like it is when it comes out of your
kiln (if you anneal correctly)
I would bet dollars to donuts that if you took the be glass up to 1300 or so and then follow your anneal schedule
that your breaking problem would be a thing of the past.
Again, It would be a lot less hassle and cheaper to go to a window repair shop and buy 6 mm float glass.
The other Jim

[AJK25]

I do fuse the clear glass to 1365 or 1370 and then anneal it to 960 (hold for 1.5 hours). If we used float glass, could we still fuse it? I assume not. I think we need fusible glass because it softens it. I think it would be too sharp if we do not fuse it.

And these issues are only happening during shipping...fortunately the glass is not breaking once it is installed on the cabinetry. But I need to be able to ship it without the worry of it breaking.

[Tony Smith]

What are you using to glue the glass to the metal? Theres a large difference in thermal expansion between most metals and glass so if you're using an epoxy, you need to be careful how, and more importantly, where, you glue the glass. A silicone is more compliant and therefore more forgiving about how it's glued.

Tony

[Buttercup]

Have you searched the archives? I remember the same question being asked several years ago. Maybe the answer was supplied then?

[Ed Cantarella]

I do fuse the clear glass to 1365 or 1370 and then anneal it to 960 (hold for 1.5 hours). If we used float glass, could we still fuse it? I assume not. I think we need fusible glass because it softens it. I think it would be too sharp if we do not fuse it.

And these issues are only happening during shipping...fortunately the glass is not breaking once it is installed on the cabinetry. But I need to be able to ship it without the worry of it breaking.

BE is currently recommending 900F for the anneal hold. And what are you doing after the anneal hold - tapering down to 600F, maybe a brief hold there.? *GlassArt magazine also just had an article about this in the March/April 18 edition.
https://www.bullseyeglass.com/images/st ... _slabs.pdf

[AJK25]

I use an activator glue from Loctite. But I also use this glue on some other clear pieces that I am not having an issue with.

I will start to anneal to 900 (I have been annealing to 960). And then I'll slowly go down to 600 or 700 degrees.

Thanks.

[Ed Cantarella]

I use an activator glue from Loctite. But I also use this glue on some other clear pieces that I am not having an issue with.

I will start to anneal to 900 (I have been annealing to 960). And then I'll slowly go down to 600 or 700 degrees.

Thanks.

Consider Tony's idea(above) about going with a more flexible glue. Maybe E6000 if you don't want to use silicone.

[Brad Walker]

Consider Tony's idea(above) about going with a more flexible glue. Maybe E6000 if you don't want to use silicone.

E6000 is silicone.

[Ed Cantarella]

Consider Tony's idea(above) about going with a more flexible glue. Maybe E6000 if you don't want to use silicone.

E6000 is silicone.

It is? The smell is bit different. Used some this morning and this concept was bugging me. Have to change my response - manufacturer(eclectic) says it's not silicone and specifically won't stick to silicone well. But it does maintain some flexibility, so yeah, a good-> better choice.

[AJK25]

Thanks very much. I will look into the E6000.

[Tony Smith]

According to the MSDS, it's a styrene-butadiene copolymer. The E6000 uses tetrachlorethylene as its volatile solvent. That means it is not a silicone and is more like rubber cement in its composition.

Tony

[Brad Walker]

According to the MSDS, it's a styrene-butadiene copolymer. The E6000 uses tetrachlorethylene as its volatile solvent. That means it is not a silicone and is more like rubber cement in its composition.

Thanks for the correction, Tony. I had always assumed it was silicone.