Film on Film, will it stick?

[JJAWS]

Smh

[H.G.]

I have always shied away from film on film per factory recommendations , ie : the hard coat "could" react with the adhesive on the second layer. But with all the "success" stories I might think again.

[Bham]

I think it was someone in the film industry that explained it to me like this.

Film works in certain direction. If you install film on the opposite side of the glass, it doesn't work the same(similar yes, but not the same)

If you layer film, you are not creating one piece that works properly, you are creating two pieces fighting each other. The layer closest to the sun will go bad faster than it is supposed too. The layer closest to you is causing the other layer to go bad.

I have also seen the two pieces slide after install, on roll-up windows.  The layer closest to you will slide over time. 

[jh812]

After stripping a back glass that was double layered a couple of weeks ago, I'd say the adhesive acts different. I probably could've left the first layer and would have never noticed the second was ever on.

[VIP tint + glass]

we do it all the time but it has to be done the right way.  and we never warranty it

 

the first piece that is applied has to be bigger than the 2nd piece.  if the 2nd layer is larger there will be an air bubble line from the overlap.  if there is any overlap; after a long amount of time (my experience is 5 years) it will develop fingers.

 

so cut the first layer larger than normal on all sides.  on the second layer cut it a tas smaller and leave the tiniest gap at the top edge.

 

we do the same when applying a sunstrip to a tinted windshield

[Tintguy1980]

I think it was someone in the film industry that explained it to me like this.

Film works in certain direction. If you install film on the opposite side of the glass, it doesn't work the same(similar yes, but not the same)

If you layer film, you are not creating one piece that works properly, you are creating two pieces fighting each other. The layer closest to the sun will go bad faster than it is supposed too. The layer closest to you is causing the other layer to go bad.      

I have also seen the two pieces slide after install, on roll-up windows.  The layer closest to you will slide over time.  But really poor adhesive grab.

If that were so you would see only one ply films produced. 

[cuda67]

I applied a darker tint so they all matched. I metered the windows and they were all the same.