installing anti graffiti film with butt joint

[Sylvia]

Hello Guys,
We mainly do decorative window films (frosted, printed optically clear, contour cut, etc) and large wall installations. Have done some smaller anti graffiti film here and there, but now we have been asked to do an entire building, with many windows being 2.4m (8') high by2.1m (7') wide. So we will need to join the film on the window as they are both wider and longer than maximum roll width.
Having done lots of butt joins on wall vinyls, we though this should not be a problem. Did a trial in our studio window and we are not happy with the result. There is a 1/16" fine line where we cut the butt join. Please see photo attached showing the line on the glass and also the shadow of it on a sheet of paper behind the glass (sorry for messy writing, done on my phone). I can't make it disappear. I have left it to dry for a day and pressed it down again. I have tried to heat it gently with a heatgun, it does not go away.
It seems the me, that because of the thickness of the film, it does not lay completly flat once cut, so it's just a tiny bit too long for the space.
The film is 3M AG4.

Is there someone around who had experience with this? Could you please help? What would you do, how would you join the film?
Thanks so much

 

[AKwrapguy]

How are you applying it? How are you doing the butt joint? Basically what's your process from start to finish?

Also if your doing a whole building, that is a lot energy being absorbed and dissipated throughout the day. There is going to be movement no matter what.

 

[Sylvia]

How are you applying it? How are you doing the butt joint? Basically what's your process from start to finish?

Also if your doing a whole building, that is a lot energy being absorbed and dissipated throughout the day. There is going to be movement no matter what.

Thanks for trying to help!
Here is our method of applying:
After detailed cleaning of the window, we reverse roll the film, separate the top 5”, while spraying it with baby shampoo + water solution. Spray the entire window except the top few inches, where the film is wet already. Apply the film to the window, remove backing, spray the film and secure it at the top, then squeegee it, middle down first, then horizontal squeegee stripes on the two sides, stopping about two inches before the frame. Do release cuts at the corners, cut the extra film, squeegee it till the frame. Apply the second sheet of film and overlap it it vertically about one inch. Once it is secured/ squeegeed to the glass the same way as the first sheet, cut a vertical line through the two layers right down the middle of the overlap. Remove little piece from the top, then carefully lift the corner of the first sheet at the top and take out the small piece from below. Spray the middle section and squeegee down the join with vertical strokes.
When we use this method with wallpaper or a thin film on glass the joint is seemless. But with the thicker anti graffiti film we are having trouble. As if the top layer is just a touch longer and cannot lay perfectly flat next to the first sheet. It is stuck down, but there is a shadow line showing / or some air? And we cannot get rid of it.
This is on a test piece on our studio window. The project we will do has many individual windows sized: 8’high and 7’wide. It is not a large seemless glass area, and there are no silicone joins.
Don’t want to apply it on the client’s window until we can do a better job! I’m hoping you migh be able to offer some advice. Thanks so much!

 

[ikarasu]

What size film are you using?

When we need to do a join on glass and it's a wet apply... We always apply the panels with the true edge of the media - the. Wet apply / slide the true edge to the other true edge... And you should get a perfect butt join without having to do any cutting... Aside from the edges of the glass. We always get perfect butt joins that way.


You'll always be able to see it... And windows flex / heat and contract, so no matter how perfect you get it, you'll have a line you can see.


Another option... We just did a doctor's office with the same 8 ft windows, and fasera frosted vinyl - we didn't like the join... So we incorporated a black decorative strip that went over every join to cover it - we try to do stuff like that whenever possible... It'll always look better than seeing a big splice in clear media.

 

[AKwrapguy]

Thanks for trying to help!
Here is our method of applying:
After detailed cleaning of the window, we reverse roll the film, separate the top 5”, while spraying it with baby shampoo + water solution. Spray the entire window except the top few inches, where the film is wet already. Apply the film to the window, remove backing, spray the film and secure it at the top, then squeegee it, middle down first, then horizontal squeegee stripes on the two sides, stopping about two inches before the frame. Do release cuts at the corners, cut the extra film, squeegee it till the frame. Apply the second sheet of film and overlap it it vertically about one inch. Once it is secured/ squeegeed to the glass the same way as the first sheet, cut a vertical line through the two layers right down the middle of the overlap. Remove little piece from the top, then carefully lift the corner of the first sheet at the top and take out the small piece from below. Spray the middle section and squeegee down the join with vertical strokes.
When we use this method with wallpaper or a thin film on glass the joint is seemless. But with the thicker anti graffiti film we are having trouble. As if the top layer is just a touch longer and cannot lay perfectly flat next to the first sheet. It is stuck down, but there is a shadow line showing / or some air? And we cannot get rid of it.
This is on a test piece on our studio window. The project we will do has many individual windows sized: 8’high and 7’wide. It is not a large seemless glass area, and there are no silicone joins.
Don’t want to apply it on the client’s window until we can do a better job! I’m hoping you migh be able to offer some advice. Thanks so much!

So the issue is the vertical seam? What if you do the top of the glass, than do the bottom of the glass giving you a horizontal seam? If you're using 54" or 60" material this should keep it out of the sight line. Maybe you could than also update the client to a ddecorative band or graphic to go over the seam as well?
Just an idea, I know that install will be a little more awkward but it should be doable.

 

[Sylvia]

Thanks for your suggestions, we will go ahead with a horizontal join and just butt joining factory edges of the panels instead of double cutting. The join will be at the level where the safety strip is on the inside. So not invisible, but still hidden a bit.
Much appreciated your input!