Lets discuss Convertible top glass separation/delamination

[bonez318ti]

I was trying to research how frequently the e88 glass separates from the fabric top. The majority seems to refer to 2008 models, so I was wondering if the later years saw any problems with the glass becoming unglued from the top. (if anyone has had problems in the later years, can you please comment - would be interested in seeing if this problem was fixed in later years).

For people that did repair, I was curious as to the type of adhesive they used, the prep they did and how long it held up.

I am about to do the repair myself on my 2008 and after a bunch of research have identified two separate problems that are rarely specifically addressed when people mention they repair it, and that I suspect may have a big impact on effectiveness of repair.

The two areas that need to be addressed are:

1) the fabric portion of the window opening that is bonded to the glass is folded over itself and glued (fabric/fabric interface)- this part often delaminates/becomes unglued. I suspect this is the initial failure that causes the glass to bmp on the metal rail at the bottom of the convertible top creating the rattling that often serves as a precursor to the glass itself becoming unglued.

2) the fabric portion that is glued to the glass. when this fails, there is obvious separation between the fabric and the glass and leaks can occur.

In order for a proper repair to occur, you must first repair/glue the 'fabric to fabric' interface, then repair the fabric to glass interface.

It seems like the consenus here is to use 3M's window weld (product 08609: Technical data sheet) with the single step primer (product#08682:Technical data sheet ). Use the suction clamps to hold pressure while it sets.

I would be interested in hearing peoples experiences with their repairs - specifically:

1) Year/model of car:
2) How long have you owned the car before there was glue failure?
3) Did you regularly apply any type of protectant to the top, if so, what type (ie: did the protectant serve a purpose in breaking down the glue?)
4) Was the care garaged regularly?
5) Was there breakdown of the fabric/fabric interface? Did you glue this first? If so, what kind of adhesive did you use? What kind of preparation did you perform to applying adhesive? How did you secure and how long did you allow to cure before proceeding with repair?
6) Was there breakdown of the fabric/glass interface? What type of adhesive did you use? How did you secure and how long did you allow to cure before proceeding with repair?
7) After your repair, how long did it / has it held for? (you can specify 2 years 3 months "and still going" or something like that if repair hasnt failed yet)
8) If you replaced your top rather than repair? (if replaced, was it under warranty? did you go with an aftermarket top, if so, which one and how has it held up)

If you have had multiple repairs with different types of glue, you can repeat the relevant data. I believe it is useful to hear adhesives/processes that do not work. You can also provide any additional data points feel would be helpful.

After my research - this is my process I plan on taking:
As mentioned, there was breakdown of the fabric/fabric interface - I am in the process of gluing it using shoe goo, then using spring clamps over popsicle sticks to apply pressure and let it cure for about 24 hours (60-80 degrees with humidity 70s). I broke this down into 3 separate phases (left/right/bottom, the top of the glass is still glued and secure), 3 phases only due to the number of spring clamps I have (I put around 15 or so on top of popsicle sticks to maximize pressure.

For the second stage, I have cleaned off as much of the old glue as I can from the top and glass(razorblade to scrape the glass and screwdriver and some razoring on the fabric). Then I plan on applying the primer to fabric and glass surfaces that will be glued using the window weld. I will then apply window weld and holding pressure with the suction clamps (i bought 2 sets, 12 total clamps). Things I have yet to do is determine whether I will raise the roof halfway or remove the fabric from frame to remove tension. If I am able to get the fabric to easily glue the glass I will probably defer the relieving tension part as more tension probably means more chance of failure once its glued (at the same time needing to verify sufficient area of fabric/glass overlap to maximize the gluing).

Ill update this thread with my experience as I finish it.

[popps9]

2013... I have owned it about 2 years...the rear glass separated about 6 months ago and since the cost of a replacement top is super high I tried the 3M and clamp repair and thus far its surviving. I hope it lasts for years. I am in Central Florida so it sees a lot of sun and heat but it is garaged.

[JimD]

I ordered my 2009 and took delivery at the performance center in mid 2009. It had wear at a crease in the sides behind the window before the back glass and it was replaced twice under warranty - about a year apart. So the top is newer. By the time of the second new top there was a TSB to add some plastic parts to the top mechanism so it folds differently and they seem to have resolved the wear issue my first couple tops had. If you have a 2008 or early 2009 e88 I would check to be sure it has had the tsb done. But it doesn't affect the glass delamination.

I have had no issue with the glass coming loose like you describe. I use Ragg Top cleaner and treatment about once a year. I used my e88 as a daily driver for maybe a year but other than that period I have always had another vehicle that my daily. It has less than 120K miles.

[lucahemi@gmail.com]

Originally Posted by JimD

I ordered my 2009 and took delivery at the performance center in mid 2009. It had wear at a crease in the sides behind the window before the back glass and it was replaced twice under warranty - about a year apart. So the top is newer. By the time of the second new top there was a TSB to add some plastic parts to the top mechanism so it folds differently and they seem to have resolved the wear issue my first couple tops had. If you have a 2008 or early 2009 e88 I would check to be sure it has had the tsb done. But it doesn't affect the glass delamination.

I have had no issue with the glass coming loose like you describe. I use Ragg Top cleaner and treatment about once a year. I used my e88 as a daily driver for maybe a year but other than that period I have always had another vehicle that my daily. It has less than 120K miles.

Any more details on where to look for the plastic tabs and what they look like? Would like to see if my 13’ has them

[LaKuan]

Same thing on my 08. Since no water is coming in.. im not worried for now. I saw some new vert tops online, im probably going to replace it sooner or later and bite the bullet. I saw a deal for $600 on a new top and for me thats the way to go.

[bonez318ti]

Originally Posted by LaKuan

Same thing on my 08. Since no water is coming in.. im not worried for now. I saw some new vert tops online, im probably going to replace it sooner or later and bite the bullet. I saw a deal for $600 on a new top and for me thats the way to go.

Where was that deal? for 600, i would probably replace it. Lowest Ive seen is around 1000-1400 (1400 for OE 'acoustic' material).

[JustAnotherSportsCar]

I repaired the top on my 2008 last summer. While I had purchased and planned to use the suction cups, I ended up deciding to pull the fabric off the rear section of the frame and removed the glass completely. To re-glue it, I folded the fabric over and placed the glass on top. I used a ton of little, metal chip bag clips from Dollar Tree to clamp the fabric to the glass. I pre-fit the glass before I glued it. I used a razor blade to clean the glass and cut away the old glue from someone else’s failed repair attempt. I used 3M Window Weld and the 1 step primer. Flipping the fabric over allows you to thoroughly clamp the fabric to the glass, though as the original poster questioned, you aren’t able to glue the fabric to itself this way.

After it cured, I cut away the excess. I put the top up and down a lot in daily use and the window weld shows no signs of failing. If you take the time to prep the glass, you should have no issue. The fabric peels off the frame fairly easily and goes back just fine.

The tabs someone is referring to, I believe, are a very noticeable issue if failed. With the windows down and top up, they blow around all over by the rear roll hoops in the interior. The tabs are supposed to press into a metal retainer. The tabs themselves have a 3-tab circle that presses into the retainer. It is these 3 tabs that break, allowing the main tab to pull off the retainer. Mine were flopping all over with the windows down and top up. I clipped off the little tabs that remained from the 3-tab circle, and pop-riveted the main tab to the retainer. I did this on both driver’s and passenger’s sides; no more issues!

[bonez318ti]

Originally Posted by JustAnotherSportsCar

I ended up deciding to pull the fabric off the rear section of the frame and removed the glass completely. To re-glue it, I folded the fabric over and placed the glass on top. I used a ton of little, metal chip bag clips from Dollar Tree to clamp the fabric to the glass. I pre-fit the glass before I glued it. I used a razor blade to clean the glass and cut away the old glue from someone else’s failed repair attempt. I used 3M Window Weld and the 1 step primer. Flipping the fabric over allows you to thoroughly clamp the fabric to the glass, though as the original poster questioned, you aren’t able to glue the fabric to itself this way.

Do you mean you released the back of the top like at 3:33 of this video:

When you say you folded the fabric over, what was the position of the rear portion of the frame with the glass, was it standing straight up? if you fold the top and place the glass on top, then i gather the top/glass is resting on the more forward part of the convertible frame. if you used the chip spring clips, did you put it where the fabric folds into itself, if so did you ultimately glue the fabric back to the fabric? if so how did you do it?
When you cleaned the glass, did you leave any part of the remanant glue at all, or did you clean it completely and then primed it? for whatever reason, prior repairs writeups/youtube vids, many indicated they left some glue there but still primed it.
How well did you clean off the old glue on the fabric top?
How long ago did you perform your repair?

[JustAnotherSportsCar]

Yes, to your question about the video. That is how I peeled away the rear portion. Don’t drill anything though, after you remove the rubber seal, the fabric has a lot of clips to release by pulling. Once the fabric is released, the frame will fall back to its resting place. I used a box to support it and the folded back fabric and glass. The fabric will rest partially on the forward section of the top. I put plastic covering down to protect the forward section from any potential spilled glue.

When I glued the glass to the fabric, the fabric did not get glued to itself. The ‘V’ the the fabric makes, allowed me to position the chip bag clips into the V and on to the back of the glass. It will make more sense when you do a practice fitting without glue.

I completely cleaned the glue off the glass and did my best to get the large chunks off the fabric. I used a razor blade to carefully go around the fabric to cut the glue down close to the fibers. It isn’t difficult, just time consuming. I did this about 1 year ago.

[bonez318ti]

Originally Posted by JustAnotherSportsCar

When I glued the glass to the fabric, the fabric did not get glued to itself. The ‘V’ the the fabric makes, allowed me to position the chip bag clips into the V and on to the back of the glass. It will make more sense when you do a practice fitting without glue.

Did you end up gluing the fabric back to the fabric (the 'V') some how afterwards or did you just leave it unglued?

Thanks for your detailed response. This is the first I have come across this approach and it seems like it would apply the most pressure to the fabric/glass interface. Im curious as to if this is more effective than using the clamps.

if you remove the fabric like in the video, do you have easy access to removing the headliner (i believe there is a plastic edge on the headliner that slots into a metal channel built into the glass) The top of my glass is still glued to the fabric, but I think the fabric/fabric has become unglued at the top and because the headliner is there, I can't access it to check or glue it up without completely removing the glass.

[NVHoo]

Even the brushless automatic washes have a blower/dryer at the end that exert tremendous downforce on the top and glass. You only have to look at that process once and see the glass vibrating like hell to realize it's not a good idea. I've owned convertibles for 50 years and never had a glass separation. I've had my 128 for 8 years and the glass is still solid. My car is garaged. Using protectant is a non-factor. In fact, most protectant is just scotchguard, so save yourself some money and get generic scotchguard.
Not a factor here in Vegas, but the other major glass killer is snow piling up on the rear glass, the constant (typically hours) of weight downforce and cold will get you.

[JustAnotherSportsCar]

I did not glue the fabric to the fabric. I know I questioned doing this, but it seemed difficult to accomplish and I was satisfied with the way the glass was attached when I completed the work. I never pulled back the top enough to mess with the head liner much, other than exposing the area around the glass. You will have to pop those tabs out that I referred to earlier. If they break, just rivet them when you reassemble.

I think removing the glass completely and cleaning it thoroughly is the best approach to sealing the glass for a long term repair. I hope it lasts beyond 5 years, and the way it is holding, it seems like it will!

[LaKuan]

Originally Posted by bonez318ti

Where was that deal? for 600, i would probably replace it. Lowest Ive seen is around 1000-1400 (1400 for OE 'acoustic' material).

After a extensive search online, i found a guy on ebay who was selling his “brand new” never used top for $600. Whenever im ready ill wait and find a good deal.

[GoRomeo]

Man you guys ROCK! Thanks for all the information you shared. Feels great to have all this info when we need it. ☝️🤤

[GoRomeo]

Originally Posted by NVHoo

Even the brushless automatic washes have a blower/dryer at the end that exert tremendous downforce on the top and glass. You only have to look at that process once and see the glass vibrating like hell to realize it's not a good idea. I've owned convertibles for 50 years and never had a glass separation. I've had my 128 for 8 years and the glass is still solid. My car is garaged. Using protectant is a non-factor. In fact, most protectant is just scotchguard, so save yourself some money and get generic scotchguard.
Not a factor here in Vegas, but the other major glass killer is snow piling up on the rear glass, the constant (typically hours) of weight downforce and cold will get you.

Great information thanks. Even though would never take my car to any car wash. I rather clean it myself along with a good brush.