Reattach Rear Window Glass to a Convertible Car Top
Modern soft convertible car tops often have glass windows glued to the cloth, vinyl or other soft material with a melted plastic strip instead of a clear vinyl window sewn to it. If and when the glass comes unstuck -- sometimes due to the canvas shrinking from neglect or otherwise -- it can be very difficult to reattach. Double-sided foam tape such as 3M VHB tape (what one author used, others could be OK too) can reattach them, but should be applied in a specific way to avoid constant strain that will break its bond.
Steps
- Reattach the soft top material ("canvas") to the glass when just part of the canvas has detached so that the glass does not have to be re-centered within the hole in the canvas. If it does have to be re-centered one might do that by measuring distances with the defrosting grid as a guide and, in any case, holding the glass temporarily in place with gaffer's or other sticky tape.
- Open the top slightly so that it is not taut. Prop something such as a small empty box between the front edge of the top and the upper edge of the windshield frame so that the top stays open slightly.
- Find the seal that was attached but has become unattached, such as the lower edge of the exterior layer of canvas. If dirt has accumulated in the pocket that has been exposed to the weather you may wish to vacuum out any large particles.
- If only a very small part has separated leave it alone. If a large part is mostly separated you may wish to separate it entirely to re-seal it as one continuous piece.
- Clean the mating surfaces with rubbing alcohol.
- Close the roof completely to see where the canvas falls on the glass when pulled gently flat as far in on the glass as it will go, but not pulled hard. At least in the case of cotton canvas, this will probably be not as far up onto the glass as originally (or as on a still-attached inside layer) because it will have shrunk since new.
- Re-open the roof slightly and re-prop it.
- Apply a strip of double-sided foam tape such as 3M VHB ("very high bond")--foam so that it will conform to any irregularities, preferably black so ultraviolet rays will not promptly destroy its exposed edge--to the glass with the edge coming up to the point you determined previously.
- Bring the middle of the area being attached (such as the middle, left-versus-right-wise of the bottom exterior canvas) up to the edge of the tape. It should have just a little slack, since it needs to be pulled basically smooth but not taut when the top is closed. Just a little slack when the top is closed is much better than tension, which will unstick the tape.
- Stick the canvas to the tape, working outward. The reason to work outward from a central point is so that any "excess" material does not build up at one side.
- Rub down the canvas over the tape firmly and apply some heat--not a great painfully hot amount--with a blow dryer for a thorough bond.
- The convertible top should be fixed.
Tips
- It may be better to get the top fixed in a way for whose possible failure someone else such as a dealer will take responsibility. But this is a great alternative to replacing the top.
Things You'll Need
- 3M VHB foam tape, black
