Bond Lexan to metal frame?

[locknut]

Made up metal window frames for the cab project using 1/2" square tube.I tried using 3M 06377 double sided mounting tape,but it will not stick to the painted metal or the Lexan.Is there something else that will work,or am I going to have to bolt it down? If so,what's the expansion factor for 1/4" Lexan?

 

[Treemonkey1000]

Would a rubber gasket material glued to the lexan work? Have the rubber gasket folded over on both sides of the lexan with about 1/2" of excess material. Then put screws through that excess rubber into your metal frame. That would allow expansion contraction and vibration dampening to keep the lexan from cracking.

 

[Jaylegger]

I tried lepages double sided tape (similar to 3m's) as well but didn't stand up to vibrations so then just used auto glass black polyurethane adhesive picked up at a autoparts retailer. A light sanding and cleaning of the metal first is all I did and though my side window are plexi so far it has held perfectly. After a little checking it appears polyurethane adhesive works for lexan too.

 

[czechsonofagun]

Little bit off, but anyway. I made wooden windows for my shop and used lexan instead of glass - sometimes I get carried away cutting the grass and them flying rocks .... never mind - To glue it to the wood I found some filler in Home Depot in the typical caulk gun package that holds it there safely and well. The window is north side and never leaks.
However since the lexan is temperature sensitive, it is pretty much convex/concave due to heat/cold dilatation. That said, I am not sure if you will not experience the same thing with lexan glued to rigid frame.

My $0.02 of course

 

[PILOON]

I have used polyurathane caulking (FLEXTRA) with success.
I essentially is similar to auto glass bonding material sold in caulking gun tubes.

Read that auto glass well bonded is considered part of many auto structures now-a-days.

 

[ToadHill]

I bonded the Lexan rear window to my race car with clear silicone. It held up at 140 mph.

 

[Steve C]

Made up metal window frames for the cab project using 1/2" square tube.I tried using 3M 06377 double sided mounting tape,but it will not stick to the painted metal or the Lexan.Is there something else that will work,or am I going to have to bolt it down? If so,what's the expansion factor for 1/4" Lexan?

a thick silicone bead that will allow for expansion and contraction

 

[rus_geek]

What about using a gasket like a skidsteer door/window? Something like this:

McMaster-Carr

There are assorted one-piece and two-piece styles:
Locking Gasket

Your local tractor/equipment dealer should have something you could buy by the foot.

 

[Window Geek]

Made up metal window frames for the cab project using 1/2" square tube.I tried using 3M 06377 double sided mounting tape,but it will not stick to the painted metal or the Lexan.Is there something else that will work,or am I going to have to bolt it down? If so,what's the expansion factor for 1/4" Lexan?

The coefficient of expansion of polycarbonate is 65 x 0.000001 x length x change in temperature ｰC.
How big is your piece of lexan? It moves a lot more than steel in the same temperature range. Try bonding one side and having the opposite edge in a flexible gasket or groove that is deep enough to expand into during the hot days.
Using urethane to bond lexan can cause some crazing in the plastic due to its solvent content, but urethane sticks to nearly everything.
I've seen some silicones fail to bond with lexan, mostly the acetoxy silicones (smells like vinegar) won't hold well, but the neutral cure silicones will do ok.
3M makes Very High Bond (VHB) tapes that are used in vehicle assembly. Those will work well as long as you have room for expansion.

 

[locknut]

Thanks for all the suggestions.I ordered some higher bonding tape from McMaster-Carr.I've ordered some moldings and stuff from them previously and must say,they are extremely easy to order from and [from here] items are on my doorstep the next day.Amazing.