Hard Top Fiberglass Repair...any hints or suggestions?

Hard Top Fiberglass Repair...any hints or suggestions?

jonboy1919

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Maltby, WA
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1979 CJ7 Renegade, 304cid, MC 2150 Carb, TH400 tranny, Dana 300 twin stick, Dana 44 front w/lock right, Dana 44 rear w/truetrack locker, 33x12.5 Goodrich's, Warn 8k, onboard air, Motorcraft TFI ignition upgrade, WipeBoy wiper upgrade, Painless wiring harness, backup lamps, Driving lamps, YJ brake booster and MC upgrade swap, Rear tow hitch
Well fellow Jeepers, I know some of you out there have cracks in your hard tops and I'm sure many of those who have a damaged cap do not have enough money in these tough economic times to purchase a new one... Jeep CJ7 Hardtop for All CJ 7 Jeeps (about $1,800 with shipping).

So somebody out there has fixed their cracked lid with fiberglass repair kits and have maybe even added their own reinforcement touch with perhaps flat steel strips over the mounting holes.

I would love to benefit from your experience. What brand of fiberglass repair did you buy? Did you add additional reinforcement? Did you grind out the cracked areas and build a form?

Attached are photos of what I am up against on my hard top. Any advice/suggestions are welcomed. Also, new seals for hardtop: are they all the same or are there cheap ones versus good ones? If so, who sells the better grade of hardtop seals?

Thanks, jonboy1919
 
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Start off by sanding down the fiberglass on the inside. Use aluminum foil on the spot that has the chunck missing. Snad a groove in the cracks then get some resin and fill them in. It may take a couple times.
 
I used to work in a shop next to a fiberglass repair shop. They would grind/sand a U-shaped channel the length of the damage most of the way thru. Then re-layer cloth and resin to refill the channel. Their reasoning was that if you don't bridge the damage, it will just crack again. I have a few starting on mine and a bolt hole to fix. Hope this helps.
 
I aquired a fiberglass canoe several months ago that had a hole in each side. Since it was free I figured I would try to fix it. I ended up using epoxy instead of fiberglass resin. I found this company that offers both.
Fiberglass , Epoxy , Composites, Carbon Fiber - U.S. Composites, Inc. They even have a powder type filler that you mix with the resin that is easily sandable. I liked the epoxy since you don't have the fumes. Hope this helps. Andre.
 
The 84 CJ7 (can't speak for previous years or after) came with 2 long flat pieces of aluminum (if memory serves correctly on metal type) that was bent into a right angle lengthwise. Sort of like a yardstick... You laid that strip down on the edge of the hardtop and then bolted your hardtop down sandwiching those aluminum pieces between the bolts' heads and the fiberglass top.

In essence, it was a giant washer that distributed the bolts' downward force from just around the bolt holes on the fiberglass to the entire edge, thus preventing the cracks from appearing in the first place.

Mine disappeared years ago, but i don't even have the hardtop on my Jeep anymore so no biggie.

When you fix these cracks, you might want to fabricate something similar to keep them from appearing again...
 
The 84 CJ7 (can't speak for previous years or after) came with 2 long flat pieces of aluminum (if memory serves correctly on metal type) that was bent into a right angle lengthwise. Sort of like a yardstick... You laid that strip down on the edge of the hardtop and then bolted your hardtop down sandwiching those aluminum pieces between the bolts' heads and the fiberglass top.

In essence, it was a giant washer that distributed the bolts' downward force from just around the bolt holes on the fiberglass to the entire edge, thus preventing the cracks from appearing in the first place.

Mine disappeared years ago, but i don't even have the hardtop on my Jeep anymore so no biggie.

When you fix these cracks, you might want to fabricate something similar to keep them from appearing again...
Someone must have made those I have a '84 that does't look like the top has ever been off and doesn't have anything like that it's just bolted thru the holes.
 
The 84 CJ7 (can't speak for previous years or after) came with 2 long flat pieces of aluminum (if memory serves correctly on metal type) that was bent into a right angle lengthwise. Sort of like a yardstick... You laid that strip down on the edge of the hardtop and then bolted your hardtop down sandwiching those aluminum pieces between the bolts' heads and the fiberglass top.

In essence, it was a giant washer that distributed the bolts' downward force from just around the bolt holes on the fiberglass to the entire edge, thus preventing the cracks from appearing in the first place.

Mine disappeared years ago, but i don't even have the hardtop on my Jeep anymore so no biggie.

When you fix these cracks, you might want to fabricate something similar to keep them from appearing again...

Thanks for the post. I'm gonna take that idea and implement it after repairing the holes.
 
We bought ours brand new so no previous owners... I wish I still had them so I could take a picture.
 
It took from March to June to finish, but I finally completed my hardtop restoration.

Most all my cracks were around the bolt holes along the side rails, a weak spot for sure. So I fabricated bolting rails out of aluminum to spread out the down pressure and torque, but also to dress it up and to hide my upcoming first-time fiberglass repair work on the bolt holes, as was suggested in this thread.



I used my pneumatic cut-off tool and a carbide bit to shave down the cracked bolt holes so I could lay in fiberglass cloth and resin, and I also decided to add in each repaired area a square steel washer for even more strength.



After cutting fiberglass cloth into strips, I mixed resin and hardener and quickly went to work on only two holes at a time (resin hardens in 10 m inutes). On one crack which was missing a big chunk, I had to build a form to replicate the frame rail shape. Again, I thought for a first-timer in fiberglass repair, it turned out OK.



One bit of advice, don't put a pre-drilled metal washer in the hole under the fiberglass, as it will squirm around and end up not centered over the rail bolt holes making it much harder to drill out later:mad:. Instead, just place a square in there without a hole.

After sanding and painting the rails, I placed the aluminum bolt down rails in place and outlined the holes to be drilled through the newly-laid fiberglass. I highly recommend starting with a small drill bit and progressively get larger. I then installed new rail weatherstripping & windshield frame weatherstrip on the hardtop.

Our weather up here in the Pacific Northwest cooperated as I set out to test my work for leaks.

I am happy to report that the restored hardtop held out the water:).
 
The 84 CJ7 (can't speak for previous years or after) came with 2 long flat pieces of aluminum (if memory serves correctly on metal type) that was bent into a right angle lengthwise. Sort of like a yardstick... You laid that strip down on the edge of the hardtop and then bolted your hardtop down sandwiching those aluminum pieces between the bolts' heads and the fiberglass top.

In essence, it was a giant washer that distributed the bolts' downward force from just around the bolt holes on the fiberglass to the entire edge, thus preventing the cracks from appearing in the first place.

Mine disappeared years ago, but i don't even have the hardtop on my Jeep anymore so no biggie.

When you fix these cracks, you might want to fabricate something similar to keep them from appearing again...

I used your idea to perfection! Thanks Sir.
 
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