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Old 05-09-2021, 02:42 AM   #1
87Skier
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Top rebuild process

I'm planning on redoing my double wall top this summer.

From what I've seen in other builds my top is far from great but it could be worse.

I haven't decided how I want to do the repairs, but I'm leaning towards cutting the topmost part of the top off, just above the windows and leaving any panel edges in place. Doing so would give me access to the back of the interior panel so I can carryout much easier and neater repairs. I also want to better join the interior halves because the middle gap is much wider and it is noticeably lower on one side than the other.

To put it back together, I plan to epoxy PVC/Divinyl foam to the inside panel then sand back to shape and cover with fiberglass and epoxy.

I think adding a core material and bonding the inner and outer panels will give it much greater strength with minimal additional weight and completely eliminates the sagging problem from returning.

Has anyone done this or at least taken this approach to repairing their top?

Let me know what you guys think
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1972 GMC Jimmy Custom 4.8L (L20)/6L90E/NP205
1989 Chevy Suburban V2500 350/Turbo 400/4.11 gears
1996 Chevy Suburban K1500 350/4L60E
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Old 05-09-2021, 12:18 PM   #2
Blazerowner
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Re: Top rebuild process

There’s a good amount of posts on this. Just be sure to use SMC for the repairs. It’s a different type of fiberglass. I have two single walls with the same sagging issue. Eventually I would like to restore them.
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Old 05-09-2021, 01:48 PM   #3
Jeff1971
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Re: Top rebuild process

The problem with just taking the very top part off is you will not gain access to parts that need preservation. The rear support arch on the double wall will need attention. Mine had cracks and years of corrosion to repair. Taking the whole outer skin off in halves is time consuming but it works.

I used carbon fiber honeycomb panels that I had scrounged from Boeing surplus years ago to become the inner spacer and support. They were just the right thickness. I also used an epoxy called West Systems for joining the halves back together. West Systems is used in aircraft and racing boat applications. You can get it online.

Jeff
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Old 05-10-2021, 07:58 PM   #4
87Skier
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Re: Top rebuild process

Quote:
Originally Posted by Jeff1971 View Post
The problem with just taking the very top part off is you will not gain access to parts that need preservation. The rear support arch on the double wall will need attention. Mine had cracks and years of corrosion to repair. Taking the whole outer skin off in halves is time consuming but it works.

I used carbon fiber honeycomb panels that I had scrounged from Boeing surplus years ago to become the inner spacer and support. They were just the right thickness. I also used an epoxy called West Systems for joining the halves back together. West Systems is used in aircraft and racing boat applications. You can get it online.

Jeff
Interesting. I looked through the Factory Assembly Instructions about assembling the top and the rear support arch isn't shown as an arch, just the top piece where the hatch attaches. It makes sense though looking at how things are setup back there.

I'll probably end up removing the entire outer shell as you suggest. I want to get to and fix several other things inside there and the driver side outer shell isn't aligned properly near the front so the gap down the bed rail is terrible.

Where do the inner and outer panels separate near the hatch? At the front?
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1989 Chevy Suburban V2500 350/Turbo 400/4.11 gears
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Old 05-11-2021, 08:19 PM   #5
Jeff1971
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Re: Top rebuild process

Each top will be different but I started on the side under the window and just worked towards each end then towards the center. There’s a lot of filler on the rear drip rail. That was the hardest part.

Jeff
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