Installed tinted PPF on my sunroof rather than window tint

[twraps]

But would the PPF have prevented damage?

I now have two rock dings in my windshield. So frustrating.

Dings likely yes, full blown cracking maybe not...depends on mass/velocity of the rock & vehicle. I am wondering whether I should find some cheap windshield on eBay and do some testing but not sure what "tool" to use to shoot projectiles at the windshield in a measured way so we can actually measure the efficiency of windshield PPF.

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[SwampNut]

Dings likely yes, full blown cracking maybe not...depends on mass/velocity of the rock & vehicle. I am wondering whether I should find some cheap windshield on eBay and do some testing but not sure what "tool" to use to shoot projectiles at the windshield in a measured way so we can actually measure the efficiency of windshield PPF.

I have a variety of such tools on hand, from a .177 kid's air rifle to a .50 BMG. I can come by your place to try them all. Your neighbors ok with loud booms?

Simulating random rock events would be SO hard.

 

[twraps]

I have a variety of such tools on hand, from a .177 kid's air rifle to a .50 BMG. I can come by your place to try them all. Your neighbors ok with loud booms?

Simulating random rock events would be SO hard.

But how would we incrementally increase the impact? We can neither change the projectile's weight nor its velocity so just about the only thing we can observe is "does it break/crack/chip"?
Don't get me wrong, this still sounds like a fun thing to do, just not science-y enough

Edit: Oh also I just noticed you're in AZ....I'm in CA :/ I can go to Oakland and get free shooting @ me

 

[csharp]

I'm a n00b and dont understand how putting PPF on the sunroof would / wouldnt be any different than putting tint in regards to the possibility of cracking it due to heat? I understand why people say not to put tint on the roof because it can possibly crack it due to heat build up, but why would PPF be any different?

 

[twraps]

I'm a n00b and dont understand how putting PPF on the sunroof would / wouldnt be any different than putting tint in regards to the possibility of cracking it due to heat? I understand why people say not to put tint on the roof because it can possibly crack it due to heat build up, but why would PPF be any different?

Not sure either but speculating - the PPF is installed outside, tint - inside. So most of the heat rejection that sunroof PPF provides will happen outside of the car instead of after the sun energy goes through the glass.

 

[SwampNut]

Not sure either but speculating - the PPF is installed outside, tint - inside. So most of the heat rejection that sunroof PPF provides will happen outside of the car instead of after the sun energy goes through the glass.

Exactly, it's the energy absorption sequence, along with the radiated and conducted thermal energy. With window tint this happens:

Sun >

Tinted glass roof absorbs some energy >

Tint film absorbs some, reflects some >

Reflected energy now comes back through the glass and more is absorbed by the glass.

Meanwhile, the tint now has to conduct the absorbed thermal energy away, some towards the glass, some inside, further increasing the total system (car) heat.

Exterior tint/PPF (same thing) greatly reduces the energy through the glass to start with, and the absorbed energy now can also conduct outward.

Note that plastic film has some level of insulation, though minor, trapping some amount of energy in the glass too.

 

[SwampNut]

I am using a couple of AI-driven/centric browsers, so I asked it to review my post and this thread to give citations and a deeper explanation.

• An exterior-applied PPF (like those marketed for EV sunroofs) often gives both better heat rejection and roof protection compared to inside tint.

If found this:

References for Further Reading:

• NGS: Exterior or Interior Window Film—physics lesson
• David Darling Encyclopedia on Heat Absorbing Window Glass
• Superior Window Solutions: The Science Behind Window Tinting
• Tucson’s Best Auto Tint: Heat-Blocking Tint Physics
• YouTube demo: Sunroof PPF vs. Window Tint
• Patents: IR-Reflective Glass with Nanocrystals or Metallic Layers
• UCL: “Intelligent glass” research, vanadium dioxide switchable coatings
• User/Forum Testimonial: Rivian Forums—why PPF is better for sunroofs

 

[Supratachophobia]

But would the PPF have prevented damage?

I now have two rock dings in my windshield. So frustrating.

Honestly, anything that could dull a pointy impact or slow a forceful impact would help in my opinion.

 

[Supratachophobia]

Dings likely yes, full blown cracking maybe not...depends on mass/velocity of the rock & vehicle. I am wondering whether I should find some cheap windshield on eBay and do some testing but not sure what "tool" to use to shoot projectiles at the windshield in a measured way so we can actually measure the efficiency of windshield PPF.

I have a 120psi potato cannon .....

 

[mkhuffman]

Honestly, anything that could dull a pointy impact or slow a forceful impact would help in my opinion.

I agree but just wonder how effective it will be for rocks traveling 75 mph into the glass.

 

[Supratachophobia]

I agree but just wonder how effective it will be for rocks traveling 75 mph into the glass.

75mph? Not effective at all. But in most cases, you are driving into them as they have fallen going the same direction as you, so some speed between 0 and 75mph, i would guess?

 

[twraps]

I just released our windshield (R1T & R1S) & sunroof (R1S only for now) protection film:
https://twraps.com/products/windshi...m-rock-chips-uv-ir-defense-for-rivian-r1s-r1t

Here is the install video:

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