What's your plan for replacing your rear deck glass?
01-24-2008, 03:37 AM
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How I repaired delamination of hatch glass
Part of my glass/hatch frame started delaminating at the top while driving the newly purchased car (from GA to ID). Below is how I fixed it....almost two years ago and it's tight as a drum still. Success is based on getting all surfaces really well prepared (degreased, scuffed with sandpaper for adhesion, the best glass adhesive made, and mostly....dumb luck.). I don't guarantee that you won't break your glass with the following method, but it worked well for me.
I used 3M windo-weld super fast urethane #08609 (maybe the best adhesive for this kind of thing available. Glass shops use it). It's calk gun size and there's plenty for a good job. Google a source or check with a glass shop. It's very Black and really nasty stuff, use lots of rags and 3m adhesive remover. I took a chance and scraped off all the paint I could between the glass and the frame (my glass was only delaminated across 2/3rds at the top). I then cleaned the area with acetone and various degreasers...then I did the unthinkable, I very carefully flexed the glass away from the metal frame (or the frame away from the glass?) with the smaller end of wooden clothes pins that I'd taken apart (BTW, I DO NOT RECOMMEND THIS TRICKY PROCEDURE..it's just a description of what I did and it worked for me. I'd do it again too). Then I used a caulk gun (set to a fine bead) to force as much of the urethane adhesive into the crack/opening (both sides) as humanly possible.. I also used a large syringe without a needle in it (warming the adhesive up helps with the flow). I used wax paper to keep the wrong stuff from sticking between hatch frame and car with hatch closed...and let it cure. It's worked great for nearly two years now even though I wasn't able to get urethane 100% the way through the small gap I'd made between the frame and glass (It's 2/3rds in places). It's worked for me but I was willing to take a chance on braking the rear deck glass with the minor flexing.
After reading up on how to do this the complete and professional seal way, that appeared to be way too much work for a hatch that was just partly delaminated. Also I didn't like the idea of "sawing" the other 3/4 of the glass adhesive loose from the frame and regluing the whole thing back together again. I figured that I could do that later if I needed to. (you should be able to do the search function and find directions for the other method). While that approach may be preferable, it's fraught with other risks and I KNOW that I'd have broken the glass that way! So, I took my chances with this less radical approach and it worked out great for me. I wouldn't reccommend any adhesive other than 3m windo-weld super fast urethane #08609 since it grips like the devil herself. It's also nasty stuff to clean off glass or carpet or body parts so be ready with lots of cleaner and drop cloths. I was pleased with the outcome and, as I said, no problems in two years.
To finish up the job, I continued to clean then seal the entire perimeter of the glass/frame both inside and outside with a fine bead that I smoothed out with my finger. I don't think I'll ever see a leak in my hatch again.
While I was at it, I cut a small hole in the deformed weather strip and snaked a small 1/8" flexible hose into it starting from about the middle of each side and up past the top corners and the hatch hinge. In essence, this gave new life to the seal and saved me from buying a new weather strip as it put the shape back in the smooshed down part of the strip. I recommend much caution with this since too stiff a tube might stress things too much. I just wanted to re-firm up the seal between that hatch and body. I was very careful...and it's working also excellent also. Never a drop of water enters the car, even in a heavy car wash. I closed the hole where I inserted the additional supporting hose with some silicone and used protective wax paper between the closed hatch and hatch/seal while it cured. Otherwise, you'd glue the hatch down permanently!
I assume no responsibility if you try this and you break you expensive deck glass. The local glass shops wouldn't touch the job so I felt I had to do something. Had they broken the glass, I'd have wanted them to replace it. My backup plan was, if I broke the glass by flexing the relatively "flimsy" frame away from the glass to stick in the satatic black adhesive, was to got the difficult route and remove glass from a 944/951 hatch that I had purchased and install it in the 968 hatch (big job, btw). Or, take the easy route and just install the 944/951 hatch until I could get another 968 hatch.
I know some people are scared of the 968 because of the cost of a new hatch but you don't have to be. There are options. The glass is very strong. The hatch frame itself is relatively flexible. Porsche only sells the glass and hatch frame assembled....and it's not cheap.
I hope you never have to do this but, at some point, many 968s will experience hatch glass delamination..but it doesn't have to be a show stopper.
Harvey
__________________
'94 968 Coupe
I used 3M windo-weld super fast urethane #08609 (maybe the best adhesive for this kind of thing available. Glass shops use it). It's calk gun size and there's plenty for a good job. Google a source or check with a glass shop. It's very Black and really nasty stuff, use lots of rags and 3m adhesive remover. I took a chance and scraped off all the paint I could between the glass and the frame (my glass was only delaminated across 2/3rds at the top). I then cleaned the area with acetone and various degreasers...then I did the unthinkable, I very carefully flexed the glass away from the metal frame (or the frame away from the glass?) with the smaller end of wooden clothes pins that I'd taken apart (BTW, I DO NOT RECOMMEND THIS TRICKY PROCEDURE..it's just a description of what I did and it worked for me. I'd do it again too). Then I used a caulk gun (set to a fine bead) to force as much of the urethane adhesive into the crack/opening (both sides) as humanly possible.. I also used a large syringe without a needle in it (warming the adhesive up helps with the flow). I used wax paper to keep the wrong stuff from sticking between hatch frame and car with hatch closed...and let it cure. It's worked great for nearly two years now even though I wasn't able to get urethane 100% the way through the small gap I'd made between the frame and glass (It's 2/3rds in places). It's worked for me but I was willing to take a chance on braking the rear deck glass with the minor flexing.
After reading up on how to do this the complete and professional seal way, that appeared to be way too much work for a hatch that was just partly delaminated. Also I didn't like the idea of "sawing" the other 3/4 of the glass adhesive loose from the frame and regluing the whole thing back together again. I figured that I could do that later if I needed to. (you should be able to do the search function and find directions for the other method). While that approach may be preferable, it's fraught with other risks and I KNOW that I'd have broken the glass that way! So, I took my chances with this less radical approach and it worked out great for me. I wouldn't reccommend any adhesive other than 3m windo-weld super fast urethane #08609 since it grips like the devil herself. It's also nasty stuff to clean off glass or carpet or body parts so be ready with lots of cleaner and drop cloths. I was pleased with the outcome and, as I said, no problems in two years.
To finish up the job, I continued to clean then seal the entire perimeter of the glass/frame both inside and outside with a fine bead that I smoothed out with my finger. I don't think I'll ever see a leak in my hatch again.
While I was at it, I cut a small hole in the deformed weather strip and snaked a small 1/8" flexible hose into it starting from about the middle of each side and up past the top corners and the hatch hinge. In essence, this gave new life to the seal and saved me from buying a new weather strip as it put the shape back in the smooshed down part of the strip. I recommend much caution with this since too stiff a tube might stress things too much. I just wanted to re-firm up the seal between that hatch and body. I was very careful...and it's working also excellent also. Never a drop of water enters the car, even in a heavy car wash. I closed the hole where I inserted the additional supporting hose with some silicone and used protective wax paper between the closed hatch and hatch/seal while it cured. Otherwise, you'd glue the hatch down permanently!
I assume no responsibility if you try this and you break you expensive deck glass. The local glass shops wouldn't touch the job so I felt I had to do something. Had they broken the glass, I'd have wanted them to replace it. My backup plan was, if I broke the glass by flexing the relatively "flimsy" frame away from the glass to stick in the satatic black adhesive, was to got the difficult route and remove glass from a 944/951 hatch that I had purchased and install it in the 968 hatch (big job, btw). Or, take the easy route and just install the 944/951 hatch until I could get another 968 hatch.
I know some people are scared of the 968 because of the cost of a new hatch but you don't have to be. There are options. The glass is very strong. The hatch frame itself is relatively flexible. Porsche only sells the glass and hatch frame assembled....and it's not cheap.
I hope you never have to do this but, at some point, many 968s will experience hatch glass delamination..but it doesn't have to be a show stopper.
Harvey
__________________
'94 968 Coupe
