adhesive tape

[Ann Demko]

I am trying to recall the name of the tape used to adhere glass to metal or metal to glass. I have been asked to apply a 3/4" length standoff to a glass window. I'm thinking the glass must be tempered because I was told it could not be drilled. The standoff, well four located in the corners, will be supporting a single sheet of art glass 30" x 12". Since the window is already in place using the hang your glass adhesive system could be problematic. Your ideas and information would be greatly appreciated.

[DonMcClennen]

I would not trust 4 little pieces of tape to last very long..... then "CRASH"

[Brad Walker]

You want VHB tape. 3M makes it. There are several types, get one for glass and metal. VERY strong. Not cheap, either.

For example: http://www.uline.com/BL_6125/3M-4646-VH ... -Foam-Tape

[Ann Demko]

Thanks Don and Brad. I checked the link for 3M 4646 acrylic foam tape and then checked it out with 3M. 3m site said it couldn't be found to I called 3M and got to speak to a real live person who was most helpful. After getting all the info I could provide they were a little hesitant about the strength of the hold since the contact area was obnly 4- 1" surface areas of contact, something about the need of four square inches of adhesion support for every pound. For everyone's information they recommended DP-100 Plus (not just DP-100). It is an epoxy that has a shear strength of 3,500 psi. It is not water thin so it should be easier to handle. Initial set is 4 min., handle strength is 20 min and final cure 24 to 48 hrs.( already forgot that info) but it is on pkg. You need a mixing gun with tips and all can be found on Amazon. Amazon is a distributor for 3M.

[charlie]

vhb tape is amazing for what it does. they install large windows with it, and some car windshields.

i have a 14" diameter 6mm round piece vertically attached to a steel frame at 4 points; each point is fastened with 1/4"x3/4" of vhb tape. it's been hanging in the az heat (118F) and cold (25F) for 7 years now.

be careful when you touch the pieces together. you only get one chance. you can get tape of different thicknesses and strengths.

[Morganica]

The big question will be whether you have enough surface area in a standoff to do the job, and I'm not sure I'd trust much less than the recommended area; I've had that stuff give way. Most of the VHB I've encountered requires a fair amount. 4sq inches per pound sounds about right.

I've gotten around it by not using standoffs and instead using acrylic or glass blocks an inch or two less than the size of the piece. If you've got a transparent piece it doesn't show that way, but it does add to the weight.