Heat Shrinking Window Film
* Warning *
Never use a heat gun on laminated glass, such as windshields and certain Mercedes back glass.
The only way to avoid using strips on a compound curve window is to use the heat shrinking method. This is an advanced technique and best left to a professional. It involves using a heat gun to shrink the excess film along the grain (toward the factory edge) and smoothing it out with a rolled up paper towel or a bondo card.
The best way to learn it is to watch one being done.
Keep in mind that the film will only shrink properly toward the factory straight edge.
On an oversized piece of tint laying on soapy water on the outside of the back window with the liner still in place facing up, squeegee a horizontal anchor onto the film to bring all the excess film into finger shapes on the top and bottom of the window.
Pass the heat gun over a finger quickly, just until you see the film react, smooth that area flat with a rolled up paper towel, then do the fingers that pop up on either side of the one you just smoothed flat and so on. After the film is all flat repeat the procedure with a bondo card instead of a paper towel. Cut the film to shape and repeat step 2 (bondo card smoothing) as some fingers will pop up after it's cut to shape. To lay it in, roll it up onto a drum stick, reverse the liner and roll it out onto the prepared inner surface. Squeegee it out, etc.
Unheated finger on left, heated
finger ready to smooth on the right.
Squeegee a horizontal anchor to
bring the excess film to the top and bottom.
You must use a heat gun on high setting, a hair dryer will not get hot enough! You are only shrinking the finger itself, just pass the heat gun over the finger quickly until you see it distort slightly, then smooth it out. If you spend just a moment too long over the finger it will burn, or shrink unevenly. The trick is not to crease the film when you smooth it, so the first time use a rolled up paper towel to smooth the finger down to keep the film wet against the glass, otherwise larger fingers will bind and crease if you use the bondo card first, repeat the process with a grey bondo card.
VERY IMPORTANT, the film will only shrink properly if the fingers are aligned with the grain of the film. As you unroll film from side to side the proper grain direction is up and down, i.e. If you have a window 45" wide horizontally and 18" vertically, using a 20" roll, the fingers need to point up and down toward the straight factory cut edge. Fingers always need to be moved toward the factory edge. Squeegee a horizontal anchor onto the glass to anchor the middle and sides moving all the excess to vertical fingers. Heat shrinking is very challenging, I recommend you watch one being done just to be clear on what I'm saying.
Using baby powder wiped onto the glass instead of water will allow you to heat shrink large areas instead of fingers one at a time. This is known as dry shrinking and is very difficult to master, but will allow you to do most windows in one piece. The following series of pictures shows me doing a dry shrink on a Toyota Camry rear window.
When anchoring the film just let it go where it wants, just make sure all horizontal fingers are moved to the vertical, usually most of the excess will be toward the sides.
This is the pattern of heating i use, it allows for more even shrinking rather than trying to tackle one finger at a time. I heat a circled area, then smooth with a rolled up paper towel. The circled areas are about 3 inches square.
From a visitor
Another method we use is to use a product called Plexus, its a plastic
cleaner that acts as a lubricant while shrinking. Most cars will come
one piece using Plexus as you shrink the entire piece of film rather
just the fingers. Cut the screen out with a one inch overlap, lightly
the screen with Plexus, use a very wet cloth to mark out the "H" to lock
middle and edges. Then use your heatgun to heat the whole area where you
have fingers. The film will react by kinda bubbling, just smooth it flat
using your hand (wear a woollen glove). The Plexus does not need to be
rinsed off after shrinking which saves a lot of time.
User submitted tips:
Tinting Tip: I find that sanding the dot matrix is the easiest and quickest way
to do it. To do the dry shrinking baby powder is the way I use to get every
backwindow down in one piece (eclipse, bug even the old vette with the verticle
defogger)make sure you leave extra film on the sides so that the fingers are not
as big. You also have room IF you crease the film. I have tried shrinking with
water, dryer sheets, and powder seems the best. TRY IT.
Email: thunder email@example.com
Tinting Tip: thanx for explaining that how to tent windows, but could u plez
show a little movie about it so i can learn that how to do it because i wanna to
see little bit how u guys did it, i,m realy thanx full for that.
Tinting Tip: On dry shrinking what I do is baby powder. I use a wet anchor
line across the middle and then I anchor my film and i shrink from that line to
the top and the bottom i use my hands to smooth out the film but be carefull
it is hot and i wear a pair or leather gloves while i do it an it works great
for me i have been able to do just about every car in piece.
Also check out the Soap Shrink Method here