Hi All,

I recently came home to a shattered back window on the lift gate. We were gone on vacation for a week and I didn't notice it for a couple days after we were back. The van was backed up to my second garage door. Not really sure how it happened. Nothing was taken from the van and I live in a pretty decent neighborhood, so I don't think it was vandals. Only thing I can contribute it too is the heat (it had gotten pretty hot in WI while we were gone).

So I'm in the process of replacing it. After a pretty good search I was able to obtain a used window from a junk yard. The glass is in good shape but it is missing 3 of the 'studs' that are imbedded in the rubber molding. I have the 3M Window Weld butyl 'tape' (3/8") to seal/adhere it to the fiberglass. Will the remaining studs plus the tape be enough to permanently keep the window in place?

If not, I can salvage the studs from the old molding but then I have to figure out how to glue it to the new window. I'm not sure what I can use to do this. I've considered JB Weld, Epoxy, super glue or something like rubber cement. Any suggestions on that? It looks like the old studs were ripped straight out leaving kind of a void in the hard rubber molding. The bottom of the void is I believe rubber (not glass).

Any suggestions?

Thanks,
Jim

 

You need something strong, so I doubt rubber cement is going to do it. The studs will be tightened to the frame by nuts, so I would consider epoxy.

 

The studs snap very easily. I did one side window and two rear windows in the past, and I just had my rear and both sides pulled and resealed a month ago by a local glass shop, because I didn't want to do it again.

Once the stud is snapped off, you can't reattach it. My rear currently has three snapped off by the PO. My glass guy would not warranty that the glass would not leak, even with urethane. He said he'd warranty the labor but that if it leaked I'd have to bring him another rear glass with all the studs.

That said, I've never had any of mine leak after a proper reseal (glass taken out, all old material removed, remounted using proper premium adhesives). The caveat is that you cannot rely on the studs to pull the glass completely into the cavity; sometimes you have to settle for the plastic moulding protruding from the hatch a bit.

Be very gentle when tightening those studs!

 

If the studs are at the bottom of the glass, I wouldn't worry about it..might leak if they're at the top or sides, though.

If the studs are likely to cause a leaking problem, or you're worried about lack of support for the glass, then just skip the butyl and use a silicone or urethane windshield adhesive instead..either of these will effectively glue the glass in place, making the studs moot.
If you can't get the glass "pulled down" and seated properly because of the missing studs, you can work around this (on the rear hatch, at least) by propping the tailgate up with the glass in a horizontal position and stacking weight as needed on the glass while gluing..don't use so much weight that it causes the glass to bend..just enough to seat it properly..if need be you can loosen the studs on the opposite side to get the high side to drop.
Make sure the glass AND the channel it sits in are both well cleaned of all old sealant..a teeny lump of dried butyl in the center will make either end stick up an appreciable amount and/or cause flexing and stress-cracks.

 

I agree with most everything Doug said. Mine were resealed with urethane, and removing *all* the old butyl is key to making it work. I haven't heard of the weights-on-horizontal-glass method, but it sounds workable for the back hatch glass, which is the only one that really looks bad if it's not seated in the hatch.

 

Ford usually uses urethane sealants on the windshield. Once the sealant is applied, the glass is placed on it, and some machine applies an even pressure on it while it sets for some pre-determined amount of time. There are no studs on the windshield, so the urethane sealant must be strong enough to hold it in place. So if you want to use the weighting method, you should place enough weight on the glass, preferably evenly distributed along the edges, that brings the pressure up to something like 15 psi. AND support the rear hatch with something, as the strong arms aren't going to be able to hold up that much weight.

 

15 PSI, even just on the edges, is a lot of weight.

 

Thanks everyone for the advice. 2 of the 3 studs that were missing are on the top, so that did concern me. I went ahead and removed the studs from the broken window, ground down the bases (the replacement window stud bases must have been smaller, older window perhaps?), and got them to fit snugly into the voids that were left behind by the old studs. I then epoxied the studs in and used more epoxy to fill the void. I used the highest strength (30 min) epoxy and let it cure 24 hours inside the house. This appears to have made a pretty strong bond. Probably wont know for sure until I go to install it.

I may go with the urethane windshield adhesive just to be safe. How tough/messy is that to work with? Any disadvantages to using it compared with the butyl tape? Looks like you have to use a caulk gun to lay a bead of it out.

I was also trying to think of methods to safely and effectively 'weight' down the window. I'm considering heavy books placed around the edges with more weight added on top if needed. Another thought is to get several of those large suction cups, place them around the edges on the inside of the glass and then hang some weight from them. All that with the lift gate supported by a ladder or something of course.


On a side note, the broken (original) glass didn't have rear defrost. The replacement I got does. I started snooping around the wire harnesses at the top of the hatch and discovered the wires - with connectors and seals - all ready there! I then pulled the blank switch cover next to the rear wiper on the dash and found the connector all wired up there too. So I think if I just get a switch from ebay I should be good to go - yes?

 

Al, it could have been 10 psi, but I honestly don't remember, as it's been a long time since I read that description. In any case, the urethane sealant will require this pressure while it sets, as there is nothing else hold the glass in place.

If you are using studs, you do not have to use urethane sealant, nor do you have to weigh down the glass for the sealant to set. The studs are to hold the glass in place, while the butyl rubber does the sealing. I would try the butyl rubber first with the studs. Get the "rope" type seal, which you can apply by hand. I used that around one of my side glass, and I used a socket to turned down the nuts by my fingers. Just make sure you turn them down evenly. The butyl rubber never sets, like the urethane does. And the urethane release toxic fumes as it sets, so you need lots of ventilation if that's the way you're going.

 

Glass went in this weekend. I decided my stud repair was strong enough so I went ahead and just used the butyl tape to seal it. Had a bit of a difficult time getting the glass to "seat" all the way in. Tightening the studs wasn't enough to get the outer rubber molding tight against the liftgate. I devised a plan and used some clamps and 1x3 wood scraps to provide a force down on the molding. I clamped one end of the wood against the door with the 3/4" side of the board on the molding. I then slowly pulled the other end of the board downward to provide an almost point force on varying parts of the edge of the glass. I could somewhat vary where the force would be by tightening/loosening the clap on the far side. Worked fairly well. There is still a small gap in a few places but it's not too noticeable. Hopefully it will still keep the water out.

Thanks for all the info everyone!

 

My rear window started leaking (about 10 years ago). I at first tried tightening the bolts, most of them broke off. I took the back window out, removed all of the old sealant and then used a dremel tool with a small grinding wheel to carefully rough up the glass and epoxied the studs on. We reinstalled the window with new sealer and it has not leaked.