Gluing glass that wasn't originally glued

I have a rear window that was originally held in with rubber seals, but the seals are no longer available. I ended up gluing the glass in with 3m windshield adhesive, and it worked for about 4 months until the glass popped out of the hatch last weekend. Is there some sort of prep that I have to do to the window to get it to adhere? I used the window primer, but the glass is super smooth still. Should I maybe sandblast or etch the area to be glued?

So is the adhesive coming off the glass, the body or both? If it's coming off the body there's a brush on primer for doing this but I don't think it will work on the glass. Urethane is a LOT stronger and has better grip, but if the car body flexes the rear glass will break.

It is coming off the glass. The urethane (3m Urethane Window Adhesive) that I used is still stuck strong to the body.

I gotta defer to a real glass guy, if there's a pro on the board. I've put glass in with butyl which was what was used before urethane and it didn't require a primer. It also stayed soft allowing the body to flex but would not transfer that flex to the brittle glass.

I just had my daughters windshield redone last week, and the glass guy (who I have known and used for 30 years) said it was likely primerless urethane. He has seen them pop before. I'd consult a pro, because by the time you buy the two $15 primers and the tubes of urethane, you could probably just pay him to do it.

Long time lurker, first time poster.

I have been doing auto glass replacement for the past 10 years. This sort of thing is finicky at best, the hardest part is getting enough urethane contact in an acceptable way to keep it from popping out. What kind of car is this for?

An alternate option is using univeral gaskets for the straigh/glentle curves and using the urethane for the angular corners of the window. There are a few different kind of gaskets out there, ill try an and find a link that shows different profiles that might be a close match to the stock gasket.

It's for a 1979 Civic hatchback.

Depending on the thickness of the glass and pinchweld and the offset of the two, one of these might work.

http://www.crlaurence.com/crlapps/showline/default.aspx?GroupID=20854&History=30587:19748:19783:20834:19783&pom=0

If one isn't available those might be your best bet aside from slathering on more urethane. Glass surface prep is key if you go that route.  

I'm not bad a improvising stuff when the need arises but its hard to relay that over the internets.

Have you looked into universal at all? There are a lot of different profiles for various industrial window type stuff.

Kenny has a great idea, JC Whitney used to carry a bunch of different universal glass seals and Rock Auto shows them too. IIRC Per used some of that type stuff on the Saab, he had to miter cut and glue it together in the corners.

Lancer007 wrote: Depending on the thickness of the glass and pinchweld and the offset of the two, one of these might work. http://www.crlaurence.com/crlapps/showline/default.aspx?GroupID=20854&History=30587:19748:19783:20834:19783&pom=0 If one isn't available those might be your best bet aside from slathering on more urethane. Glass surface prep is key if you go that route.   I'm not bad a improvising stuff when the need arises but its hard to relay that over the internets.

Thank Lancer, thats some good info...

Welcome aboard, Lancer007.

Check the email you registered with.....I just sent you a PM with my own windshield questions r.e. my datsun replica.

Lancer007 wrote: Depending on the thickness of the glass and pinchweld and the offset of the two, one of these might work. http://www.crlaurence.com/crlapps/showline/default.aspx?GroupID=20854&History=30587:19748:19783:20834:19783&pom=0 If one isn't available those might be your best bet aside from slathering on more urethane. Glass surface prep is key if you go that route.   I'm not bad a improvising stuff when the need arises but its hard to relay that over the internets.

It seems that nothing aftermarket has ever matched the needs of a replacement. I'm thinking that the glass prep was my issue, but I don't know what to do for prep aside from acetone and primer before the urethane...

In reply to sobe_death:

Spray down the edges with a cleaner of the window then take a fresh razor and make sure any previous residue is taken off of both sides. Then prep both sides with the primer and install. Make sure you get the urethane creates a kind of replica and gets on both sides. It will probably get messy but with limited contact area that might be the best way to do it.

In reply to JoeyM:

You has mail.