Bond plastic to glass?

[SuzukiGS750EZ]

Hey guys. I have some gate hooks (retractable gate) I need to epoxy to a glass panel. What would be recommended to do this?

 

[ericg]

This to That (Glue Advice)

How to glue this to that

www.thistothat.com

 

[SuzukiGS750EZ]

I don’t really care about the visibility but it needs to have good peel strength and adhesion.

 

[4xdog]

"Plastic" is a broad term. What specific polymer are you trying to bond to the glass?

 

[tncatadjuster]

shoe goo

Is shoe goo just silicone?


Shoe Goo is composed of: Styrene-butadiene, a synthetic rubber with good abrasion resistance. Toluene or tetrachloroethylene solvent. Solvent naphtha, a cleaning/degreasing solvent.

 

[AffableCurmudgeon]

I would suggest a UV cured resin.

 

[ike]

Suction cups

 

[SuzukiGS750EZ]

"Plastic" is a broad term. What specific polymer are you trying to bond to the glass?

If I had to guess, ABS. The part isn’t stamped and they don’t list it in the description of the gate.

 

[4xdog]

If I had to guess, ABS. The part isn’t stamped and they don’t list it in the description of the gate.

ABS is a logical choice -- quite likely. It's a decent one for bonding, too. 2-component epoxy would be a fine choice. I'd probably use a filled epoxy to minimize dimensional changes with temperature.

For weatherability, if it makes sense, paint the polymer and the adhesive line with a good exterior paint. That'll minimize UV degradation and extend the pieces life.

 

[SuzukiGS750EZ]

ABS is a logical choice -- quite likely. It's a decent one for bonding, too. 2-component epoxy would be a fine choice. I'd probably use a filled epoxy to minimize dimensional changes with temperature.

For weatherability, if it makes sense, paint the polymer and the adhesive line with a good exterior paint. That'll minimize UV degradation and extend the pieces life.

Any 2 part epoxy? I was worried about the smooth glass letting go of the epoxy

 

[4xdog]

Any 2 part epoxy? I was worried about the smooth glass letting go of the epoxy

Yeah, debonding of the epoxy from the smooth glass surface is a possibility, even if the surface chemistry is favorable. What kind of stress and in what direction will the hook see? Maybe run a few experiments on the benchtop before doing the real thing?

Another option -- depending on the configuration of the work -- is 3M's VHB (Very High Bond) double-sided tape. That stuff's amazing and will bond well to glass. The possible exposure of the back side of the glass to UV could be a concern. Even though the VHB adhesive is acrylic (as far as I know) and could be quite resistant to UV, I don't how 3M rates VHB for UV. Maybe an opaque mask on the glass opposite the bond could protect the tape if it's gonna see UV. Paint, a sticker, a plate of plastic or metal -- anything to block UV from the bond area.

 

[SuzukiGS750EZ]

 

[SuzukiGS750EZ]

The walls are parallel to each other. So the hook pictured above will be the way it is in the photo on the glass panel. The gate in the photo would be turned 90 degrees (not that it matters). The gate is going across some stairs. It’s not a safety device but more of a deterrent (we keep a close on our 20 month old) but we have two dogs and two older kids and anything can happen. So the more durable I can make the bond the better. The hook won’t be getting pulled straight on but rather at 90° to the bond.

 

[LopezBart]

Even though the VHB adhesive is acrylic (as far as I know) and could be quite resistant to UV, I don't how 3M rates VHB for UV.

The glass will block the UV from the backside... and it's fine outdoors afaict - it's held solar panels in place on our Airstream for more than a decade, and it lives outside.

 

[4xdog]

The walls are parallel to each other. So the hook pictured above will be the way it is in the photo on the glass panel. The gate in the photo would be turned 90 degrees (not that it matters). The gate is going across some stairs. It’s not a safety device but more of a deterrent (we keep a close on our 20 month old) but we have two dogs and two older kids and anything can happen. So the more durable I can make the bond the better. The hook won’t be getting pulled straight on but rather at 90° to the bond.

The orientation in the photo is simple shear (one plane sliding against another). Most adhesives are strong under shear stress. I like that one.

The orientation you're using, with one plane in tension perpendicular to the other is in peel. That's a tough one. The stress is concentrated on the line of contact where the gate plane intersects the wall plane. A lot of bonded systems that are fine in shear don't do well in peel -- look at some of the removable picture hangers, for example.

Is the gate retractable and under constant tension, or is it sorta loose when latched across the passage? No tension is better.

 

[SuzukiGS750EZ]

The orientation in the photo is simple shear (one plane sliding against another). Most adhesives are strong under shear stress. I like that one.

The orientation you're using, with one plane in tension perpendicular to the other is in peel. That's a tough one. The stress is concentrated on the line of contact where the gate plane intersects the wall plane. A lot of bonded systems that are fine in shear don't do well in peel -- look at some of the removable picture hangers, for example.

Is the gate retractable and under constant tension, or is it sorta loose when latched across the passage? No tension is better.

Initially it’s under tension but once you lock the retractable side it locks the gate in place and spring tension is transitioned to a static load across the hooks.

 

[no704]

Rear view mirror adhesive. Or windshield urathane. Both will require a primer on both surfaces.

 

[4xdog]

If I had to guess, ABS. The part isn’t stamped and they don’t list it in the description of the gate.

A piece like that could easily be polypropylene, too. PP is almost an engineering thermoplastic, but for its heat distortion temperature. If it is PP, a waxy polyolefin, it's harder to bond adhesively. I lean more toward VHB tape in that regard.