thicker and thinner together- ok?

[Bonnie Rubinstein]

Hi all, I have fused and 40" x 24" piece, the base double thick clear. There are many added elements fused flush, but there are large areas that are just the DT clear without additional glass. I later tack fused some additional elements on, and they are 3 or 4 mm thicker than the 3mm base of the glass. The glass is well- annealed for hours. This will hang on a wall. Should I be concerned that the 3-D pieces were not fused down long enough to even out the thickness more? I just don't want the glass to go into thermal shock, or be fragile. thanks!

[Brad Walker]

Assuming you annealed properly, you shouldn't have a problem.

[Dick]

Brad is right, and remember it is not just the annealing for hours, but the cool down is critical. A lot more stress is added with uneven thicknesss.

[Bonnie Rubinstein]

Yep, took most of the day to cool that puppy down. Then it just sat in the kiln for 3 days.

Thanks so much, what a relief! (pun intended).

[Bonnie Rubinstein]

For this 24" x 40" piece, I am about to drill 4 holes not far from 4 corners (5" in from width, 2 1/2" from top and bottom), to secure with stand offs to the wall. The overall glass is about 1/4" thick, except for the tack fused, thicker elements, as described above. Since the piece is only 1/4", should I be concerned with how much pressure is put on the glass at those 4 support points? thx!

[Bonnie Rubinstein]

P.S. the holes will be about 5/16" diameter.

[Tony Smith]

The rule of thumb is twice the diameter of the hole from the edge of the hole to the edge of the glass or a minimum of twice the thickness of the glass. I also found a reference to 6 diameters from the corner of the glass. I think your dimensions are very conservative and should work fine. Support your glass well under the drill to reduce chipping and radial cracking. Inspect the holes after drilling and don't hang it if you see any cracking.

Tony

[Bonnie Rubinstein]

Thanks, Tony.
I have been debating with myself about whether to use 4 edge grips, 2 on bottom and 2 on top- whereby the glass is sitting inside of the grips for support; or 4 standoffs, whereby the bolts inside drilled holes support it. I have used edge grips in the past. But this client wants to use the standoffs, so I am consenting- just a bit cautious.
What do most glass artists use to hang, i.e. a 20 lb. large glass piece with no frame?

[The Hobbyist]

Have you considered "Hang Your Glass"? I've used them on a few pieces with success.

Jim "The Hobbyist"

[Bonnie Rubinstein]

Hi Jim,
For the size and weight of my work, not willing to risk. Also, the back of my work is not smooth, but has slight bumpy irregularities, so not sure if this would affect the bonding. I will be trying Hang Your Glass for smaller work in the future, however.

[DonMcClennen]

I have hung several panels with 2 cables or chains over many years similar in size and weight you are stating. I drilled 3/16" dia. holes in 1/2" to 3/4" from each edge. Always had good results... I use the spherical diamond drills... drill holes under water.. supported on underside.... not really drilling, more like grinding hole with moderate pressure. After 100's of successful results I am confident you'll be fine!

[Bonnie Rubinstein]

I have been using hollow core diamond bits with water to drill the holes. Very safe.

[Dick]

I use stand offs all the time. Some I have drilled, but most I adapt the standoffs with a set screw, glue the cap to the back of the glass and install. I will try and add a photo.

[Bert Weiss]

Bonnie

I consider successful drilling to be a successful annealing test. If there are internal stresses, drilling will find them.

Bert