View Full Version : Vent window glass removal

03-31-2017, 10:44 AM
I got a used vent window from Carl, but it has (had) clear glass, while my vent window has a light green color. So i need to swap the glass. Tried to remove the clear glass from the new window by heating up the glass with a torch (heating equally over the entire glass área), but suddenly the glass cracked. Only one side cracked, the other side was still ok. Should i have heated up both sides, since the pane is made out of two layers? Is it possible to heat it up in water, or would the boiling point not be sufficient to weaken the sealant?
I will have to remove now the green glass from the old window, but would not like to damage that one.

03-31-2017, 11:27 AM
The first thing to determine is if the glass was installed with the window tape or someone replaced the glass and used a sealant.
If the glass was put in with tape, I would not heat the glass, but instead heat the metal frame to help release the tape and glass. I think I put the glass in a vise and protected the glass with some rubber or some softer material to hold the glass. Then I took a small block of wood and just tapped on the frame to get it to release from the glass.
If someone has used a sealant to install the glass in the frame, I think you would need to use a razor blade and try to cut the sealant inside the frame as best you can to get it loosened up.
These are just things I did when I changed my glass. Fortunately, all my glass was still installed with tape.
Another option would be to take it to a glass shop that does it everyday and let them do it. Might be cheaper than having to buy a new glass.

03-31-2017, 12:06 PM
Thanks Nyles. It seems indeed to be some kind of tape which is in the frame, no sealant.
I wonder if a glass shop overhere would do the job, they are most probably not used to this kind of glass installation, but i could give it a try.
How did you install the glass, used the same tape again?

03-31-2017, 12:15 PM
There's only a couple of ways to install glass. If a glass shop can't do a simple job like that they shouldn't be in business.


03-31-2017, 12:16 PM
There's only a couple of ways to install glass. If a glass shop can't do a simple job like that they shouldn't be in business.


My concern is more with the removal of the glass.

03-31-2017, 01:30 PM
I had one vent window frame repaired by a welder. When returned to me, I noticed the heat had begun to walk the glass out of the frame. I tapped the glass back into the frame with a 16 oz. mallet.

I heard that you can place the glass in a vice with each side properly cushioned, heat the frame and tap the frame away from the glass.

But I'd trust the shop to R&I the new tinted glass and install the latch. It's a no brainer.


03-31-2017, 06:41 PM
I used new tape going back together. A little soap water made things slide into place pretty easily. Once the water dries, the glass is locked in place.
One thing that makes the vent glass a little tricky is the metal boss where the latch goes. The tape won't fill the area completely so I just used a small amount of sealant to fill the gap.

04-01-2017, 04:19 AM
This job is neither technical nor difficult. If your glass cracked, it is because you did NOT heat it evenly. Yes, the frame touches both sided of the glass. Whether you heat the frame or the glass makes little difference to the tape. The melting point remains the same. I have never had a problem removing any glass.

Modern cars use urethane, not tape. Urethane cures in one day, seals properly and it can be cut or trimmed with a razor. That is what I use as well. - Dave

04-01-2017, 08:45 AM
Back in the day glass shops had a tool for removing the frame from flat glass. It has been several years since I've seen one but as I recall it had two opposing rubber pads that could be tightly clamped against the glass and two sets of rubber pad type clamps that fit on both edges of the frame. There was two crank mechanism that extended each of these clamps. You had to crank first one then the other, alternating until you had moved the frame clear of the glass which was still clamped tightly.
The flat glass is normally held in the frame by 'glass setting tape' which comes in various thicknesses. Some of this tape is rubber, some is fabric covered with rubber or rubber embedded with cork. After selecting the proper thickness for the frame and the glass thickness it is usually folded around the edge of the glass and the frame forced over it. The glass is held in place by the friction of the setting tape on the glass AND the compression of the frame on the tape/glass combination. The aforementioned tool can also be used for assembly, but most often a rubber mallet on the frame does it quicker.
When the frame is spread too much or when rust has decreased it's clamping power urethane can save the day, but it is difficult to remove once it sets up.

04-01-2017, 01:24 PM
Carl is right and he gives great history.

If you're not familiar in working with urethane, it can seem daunting. Glass tape will not cut very easily. Urethane cuts very easily. At Ford, if we have glass that was mis-set and immediately removed, we set it on a rack for a day to intentionally let the smeared urethane set.

The next day, a razor blade easily cuts the cured urethane off, then we re-apply fresh urethane and set that same glass in the next car.

I understand this glass is set in a frame. The hardest part of setting 'side vent' glass is to center it in the frame. Using tape is a 'no-brainer' because the tape takes up so much room on both sides. Urethane does not. In fact urethane is very liquid. So, little 'tabs' are used in a channel. They can be made of Styrofoam, but they simply center the glass in the frame until the urethane cures.

If glass set in urethane needs to be cut out of a channel, there is plenty of room between the glass and channel for a razor blade. After the glass is out, remaining urethane can be cut out of the channel very easily. BTW, new urethane sticks to cured urethane very well so not all the old urethane needs to be removed in the channel. Glass set in urethane does not leak and the finished product renders beautiful results.