blank out glass

[AndyTea]

Hiya Nick

I dont see why you should have any problem with the heat on the windows and i actualy know of a film which is white on one side and black on the other. if you are intetrested let me know and ill advise you.

AndyT 😀

[Andy Gorman]

Mmmm, that’s a risky business. Black vinyl can crack glass, I’ve done it!
It depends on how the glass has been fitted and whether there is room in the frame for it to expand, because it will expand.

There was a very long discussion on this a while back – might be worth doing a search on the boards.

[Matty Goodwin]

Andy!

Are you trippin’ mate?

I fitted black vinyl at Mc Donalds windows in their drive thru at over 30 restaurants over the last couple of years and not one has cracked, broken or shattered!

As far as Andy T says yes the material is Blockout. Its used to stop light showing through on banners etc..

I’d love to here if black vinyl has broken anyone elses windows tho! (sorry Andy G)

[Martin Oxenham]

He’s not trippin’ I’ve also had that problem with vinyl cracking a window.
Do a search for the original post.

[Andy Gorman]

McDonalds? You mean those nice modern buildings with nicely fitted glazing, which probably has plenty of room for expansion and contraction in the frame. 😉

Trust me, it can break glass. I think it is probably safer to do full coverage than say, a stripe, as the heat will be distributed evenly but it does happen.

[Matty Goodwin]

I hang my head in shame and curl in a ball in the corner!

Seriously tho, If a customer asks for a window to be ‘blacked’ out do you..

A. Walk away

B. Advise him on what might happen and loose the job/risk doing it

C. Fit the job and when he comes back with broken window deny all knowledge

Curious to no peoples thoughts…

[Warren Beard]

option B with a signed waiver from the customer.

Getting in a glass company to inspect first for possible problems could also be advised and if rejected to be stated on the waiver.

I’m not one to walk away from any work but if it can’t be done right or safe then any decent person should walk away.

Cheers

Warren

[Bob Scullion]

Nick

Andy and Martin are correct, fitting a dark film/vinyl to glass can crack it if its laminated glass.

If its toughened/tempered you can fit with confidence of no breakage.

I am sure there is a privacy film thats black on one side and white on the other, check with Nik Sanders @ Bonwyke, he’ll know (01329289621)
or Ken Jackson @MVM Films 08452703518. or you can just do as you said and fit black vinyl to one side and white to the other, as long as its toughened glass. ( there should be some markings on the glass, a BS number and most say toughened or tempered if it is, if unsure ask a glazier to check it for you, better safe than sorry)

With laminated glass it absorbs solar energy and if the glass has any defects, small edge shells or hairline cracks in the gasket will cause these to expand.

Bob

[Matty Goodwin]

Hi Warren

Original post being 1.5m x 800mm window to be blacked out.

How much would a glazier charge to come out and look at it?

Then getting a customer to sign a disclaimer?

I may be wrong but I certainly wouldn’t pay to have a window blacked out only to sign to say if its breaks ive got to replace it!

Would you pay a mechanic to change your gearbox and sign a disclaimer to say it might right your car off?

Maybe I’m being nieve….

[Andy Gorman]

I know what you mean, it’s a pane in the arse (pane…geddit?).
All I know is I had it happen to me once, and fortunately the customer was a good bloke. He replaced the glass and we did the job differently.
Now I advise against dark coverings on windows unless I can see a kite mark. If they choose to go elsewhere that’s their choice. I haven’t got time for arguments over who is responsible for broken windows.

[Warren Beard]

quote Matty Goodwin:

Hi Warren

Original post being 1.5m x 800mm window to be blacked out.

How much would a glazier charge to come out and look at it?

Then getting a customer to sign a disclaimer?

I may be wrong but I certainly wouldn’t pay to have a window blacked out only to sign to say if its breaks ive got to replace it!

Would you pay a mechanic to change your gearbox and sign a disclaimer to say it might right your car off?

Maybe I’m being nieve….

You asked what we would do and I told you 😕

A lot of customers want stupid ridiculous things sometimes and who are we to argue? All we can do is advise the possible problems and consequences and the waiver to to prove you did tell them and they still wanted to go ahead with it otherwise they will just say you never told them.

If they want it done they will get it done, as long as it’s not deemed dangerous then take their money but make sure you have protected yourself with a waiver, if they don’t want to sign it then you know they will screw you when it breaks and that’s why you would walk away.

So if somebody phones you to black out a window you simply tell them no thank you and hang up?

[Nick Williams]

thanks for the replies 😀

[Stuart Miller]

As Bob and others have said Blackout can crack glass by thermal stress.
Doesn’t matter film or vinyl the black out will cause the glass to absorb solar energy and heat up.
You could fit for years and have no problems but it is more luck than design. It could all have been toughened glass, also depends on quality of glass, how much sun it gets, and shading patterns.
Thermal stress cracks usually occur from the edge of an already damaged pane of glass.

With Laminated and normal float glass (annealed) all the edges have lots of tiny cracks from the way it is scored and cut. Each one has the potential to propagate under heat. Heat stress is more prevalent where a pane is heated quickly or there is a difference in temperature across the pane, such as where an alcove shades part of the glass first thing in the morning. If the glass is Laminated or annealed we would definitely warn the customer and suggest lighter films or vinyl.

Toughened or tempered glass is made by heating and is made to a particular size with the edges sealed so is far more likely to withstand the amount of heat absorbed. I wouldn’t worry too much if it is toughened.

We often come across windows that a window film manufacturer will not warranty against cracks and we advise the customer of this. They either sign a waiver or go with a film we advise as suitable.

It is a sign of professionalism and knowledge that you warn of problems. If they still want to go ahead that is their choice.

Its more like the mechanic saying he can fit an old gearbox to keep you going (because the customer already had it) but he would advise an new one.

A glazier should charge more than the time it takes to visit the site.
It takes 30 seconds with a meter. We test all glass we film and look for any potential shade patterns on the glass.

While I don’t give a written warranty on the glass on any sign job, like we do with window films, it is still in our minds when surveying each job and we will try and steer the customer away from dark materials on annealed glass.