Thermal Expansion on Glass

[JTBoh]

So, customer wants perf on the outside, (already installed) and now wants greyback on the inside, for a step and repeat style wall.

I remembered that black vinyl on glass can be bad - wondering if
1. anyone has actually ever seen thermal expansion from vinyl cause a break or crack
2. if this will be OK. Someone hold my hand. Anyone ever done as described?

Already took his money, and sent the CYA disclaimer over... but why not ask here too.

http://www.signindustry.com/installation/articles/2004-02-02-JL-VinylToGlass.php3
"One thing you cannot accommodate for is sunlight. For that reason, you should steer clear of using dark graphics and vinyls on window fronts, according to Jeff Stadelman, technical marketing manager
for the graphics product group at MACtac, a manufacturer of pressure sensitive adhesive. “If you cover window fronts with dark vinyl, then the vinyl will absorb more heat. It will also hinder the ability of
the glass to give that heat off,” he says. “Eventually, the glass could actually explode because of the prolonged intensity of the heat.”

 

[Big Rice Field]

The coefficient of linear expansion of glass is 0.4 in/in/Degrees F x 10 to the -5th power. This information is straight from the Machinery's Handbook, a reputable source.

 

[Gino]

The coefficient of linear expansion of glass is 0.4 in/in/Degrees F x 10 to the -5th power. This information is straight from the Machinery's Handbook, a reputable source.

What does that even mean ?? Can someone translate that into some language ??

 

[tim99]

i have never heard of glass shattering due to vinyl being applied... as far as heat goes i guess that would depend on the build quality of the window. if you think about windows on cars they can stand very high amounts of heat from being closed up and out in the sun all day.. long story short just take a look at the glass. is it double pane? if so i would go for it and not even worry. if its an old thin single pane i would use cautious because of its age and thickness.

 

[Jester1167]

My experience is that a black background with large white/light text is where the problems happen. The black heats up quickly and the white doesn't especially in the cooler months. Double pained glass makes this less of a problem.

The key is to never install graphics on cracked or chipped glass without notification and documentation because it can make it worse, and removal can cause it to break too.

 

[DerbyCitySignGuy]

You absolutely 100% can cause glass to break by installing black vinyl. Whether it WILL happen or not depends on a lot of variables that are nearly impossible to quantify (maybe not for super technical types).

Dark vinyls absorb heat rapidly and changes the temperature of the glass (where it's applied, not in all areas). The glass gets too hot, it cracks (or explodes if it's tempered).

Put a glass in the freezer, pour hot water in it (or take a hot glass and pour cold water in it). Same concept.

 

[zstekovic]

It can explode like bomb
We where helping other company to do tinted windows on one hotel, and tolerance was extremely tight between glass panels and frame (company that put glass in frames did not do stelar job of documenting it, and give us wrong specs). In the morning all we can hear is (around) 5x10 feet glass panels exploding in order of sun hitting the windows (every 3 minutes or so).
Fun times
It was on Adriatic sea shore - so lot of heat&sun.

 

[DerbyCitySignGuy]

It can explode like bomb
We where helping other company to do tinted windows on one hotel, and tolerance was extremely tight between glass panels and frame (company that put glass in frames did not do stelar job of documenting it, and give us wrong specs). In the morning all we can hear is (around) 5x10 feet glass panels exploding in order of sun hitting the windows (every 3 minutes or so).
Fun times
It was on Adriatic sea shore - so lot of heat&sun.

Oof. I bet that was like a punch in the gut. I've never actually experienced it first hand.

 

[rjssigns]

IG(insualted glass) panels are touchy. There are actual formulas that tinters use to calculate the correct shade(darkness). Same goes for single pane.

A school not far from me experienced this first hand. They turned down my friends bid because the tint wasn't dark enough in their opinion and that his bid was too high.
School had some low-baller come in and tint. Blew out all the panels. Guess who got called after the new windows were installed?

 

[zstekovic]

Yea it sucked for everyone involved, but at least it was not our fault. Just really wrong technical spec that was different than tolerances between glass actually installed.

 

[Big Rice Field]

What does that even mean ?? Can someone translate that into some language ??

It is shop mathematics. A universal language.

 

[Gino]

Maybe for you, but the average shop person barely knows increments in anything less than 1/8" and you think people see this and instantly see the constants in decimals going to the 5th power...... ?? Good luck with that one.............

 

[DerbyCitySignGuy]

Maybe for you, but the average shop person barely knows increments in anything less than 1/8" and you think people see this and instantly see the constants in decimals going to the 5th power...... ?? Good luck with that one.............

Maybe at your shop. Here we routinely deal with dimensions in the ten thousandths. If an employee can't read a tape below 1/8", I'd be seriously concerned.

 

[Gino]

Evidently, you didn't see the little laughing character the first time or the cheers guy the second time..... kinda indicating a tongue-in-cheek statement. Bedsides, I said the average shop person. Ever see the silly requests in this place ?? Oops, I forgot, you're just out to make a statement, huh ?? Try lightening up there, derby, my boy.

Sooooo, you understood his first statement ?? Ha..... I didn't think so.

 

[DerbyCitySignGuy]

Evidently, you didn't see the little laughing character the first time or the cheers guy the second time..... kinda indicating a tongue-in-cheek statement. Bedsides, I said the average shop person. Ever see the silly requests in this place ?? Oops, I forgot, you're just out to make a statement, huh ?? Try lightening up there, derby, my boy.

Sooooo, you understood his first statement ?? Ha..... I didn't think so.

Here we go. Somebody disagreed with Gino.

Yes, I recognized the first statement and understood it for what it was.