Apis Mellifera
Apis Mellifera HalfDork
8/23/19 1:18 p.m.

The windshield was cracked in my '72 Gran Torino when I bought it.  I had a new windshield installed while at work one day and the guy said Ford used butyl back then.  The old windshield popped right out and he used urethane to glue in the new windshield.  He said he couldn't guarantee that it wouldn't leak.  I went home and immediately cracked the new windshield installing the trim so I bought a new windshield and installed it myself.  I used 3M windshield urethane and 3M pinchweld primer.  The next time it rained, the windshield leaked.  I went over the seam with silicone and assumed it was fixed.  I've been commuting in the Torino this week and it rained today.  Leaks like a sieve.  I've ordered a windshield remover tool set and plan to clean off all the old and new adhesives and start over with urethane.  Am I missing something?  I don't know how it could leak and why more sealant causes more leaks.

ShawnG
ShawnG PowerDork
8/23/19 2:09 p.m.

I've used both and had good luck.

If you're not worried about rigidity, I'd use Butyl again. If you get a leak, just park the car in the sun for a few hours and gently push the glass down into the seal again and it should seal.

Urethane is great but I hope the guy used the proper foam pads to hold the glass off of the frame or you'll have a heck of a time cutting the windshield out.

jimbbski
jimbbski SuperDork
8/23/19 4:00 p.m.

They used butyl back in the day, I would use butyl.

Shadeux
Shadeux Reader
8/23/19 4:38 p.m.
ShawnG said:

I've used both and had good luck.

If you're not worried about rigidity, I'd use Butyl again. If you get a leak, just park the car in the sun for a few hours and gently push the glass down into the seal again and it should seal.

Urethane is great but I hope the guy used the proper foam pads to hold the glass off of the frame or you'll have a heck of a time cutting the windshield out.

Wow, no E36 M3! My wife's Jeep had it's third windshield replaced and they didn't use spacers. The glass guy came out and in an hour he was actually screaming profanity. My wife reported him. He got fired. The replacement glass guy used so much Butyl it just blorped out all over. They told her it was ok. Yeah, no. The next time they did a decent job. Do not mess with wife's car.

Streetwiseguy
Streetwiseguy MegaDork
8/23/19 4:46 p.m.

You guys don't have as good a glass guy as I do.  

No way does a properly urethane installed windsheild leak.

Rust hole outboard of the urethane?

 

ddavidv
ddavidv PowerDork
8/24/19 7:19 a.m.

If you're getting glass installed by the big chain that advertises everywhere, good luck with that.

My pro tip on getting windshields done is to visit a couple local body shops and ask who they use. You should quickly get a consensus. Use that guy.

I'm pretty good friends with the local go-to glass guy and have learned a lot just talking with him. There are a lot of hacks in that business.

Slippery
Slippery SuperDork
8/24/19 8:04 a.m.

Did you have a chance to see if the windshield leaked when it was first replaced by the pro? If it didn’t I would call him again. 

Apis Mellifera
Apis Mellifera HalfDork
8/24/19 2:55 p.m.

No.  I literally drove home from work, got out of the car, picked up the trim, and broke the glass.  It was in maybe two hours.  Knowing I needed a new windshield and the urethane would harden, I went ahead and pushed the new windshield out.  The original cracked windshield didn't leak.  There's no rust.  This is a sealing issue.  My guess is the butyl residual didn't allow the urethane to stick.  I've ordered butyl and the tools to cut the windshield out.  I plan to pull it and wire wheel the urethane out then reinstall like Ford did it.

The installer was a local shop.  Safelite wouldn't do it.  Probably because of the butyl.

Apis Mellifera
Apis Mellifera HalfDork
9/2/19 7:50 p.m.

Just a follow up for anyone replacing the windshield in an old car that originally used butyl. 

I removed the third windshield on Saturday and the urethane only stuck in about three places. Of course this was enough to cause the windshield to break, but the urethane did not stick anywhere that had butyl residue.  The places where it was stuck, it was really, really stuck.  I now know that nothing I could have done would have properly sealed it (I tried five times).  I’ve got the butyl and will order another windshield. Hopefully the fourth time will be the charm. 

Also professional windshield removal tools are the way to go.  That said, I don’t think it’s possible to remove a properly urethaned windshield intact even with the right tools. 

ShawnG
ShawnG PowerDork
9/2/19 7:58 p.m.

Couldn`t have been cleaned properly.

I`m not a "glass guy" but I've put in plenty of windshields at work, you need to be really picky about cleaning.

I've got a wood chisel that I no longer care about which is used for urethane removal. That stuff is horrible but it works.

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