Hey all, the PO of my '78 Chevy shorty apparently used ceiling materials that were way to heavy and upon removing them I found my center support rib has separated from the roof and the one closest to the front is on its way. It was originally stuck together with some sort of foam with adhesive on both sides that has long since dried out. What type of adhesive would be best for gluing it back together? Neither the beam or ceiling is damaged in any way, it just needs some re-sticking.

I'm thinking of using Surebond Metal Bond but am curious to know if anyone has any better suggestions. Thanks in advance!

Welcome to the site Scrojira ...

Havent run into that yet ...

I believe Ram4Ever has some experience with this and found a good product made by 3M to resecure the roof ribs to the roof skin. Unfortunately, I don't recall what that product was. Maybe he will chime in, or maybe you could try sending him a PM.

I was just about to post this exact thread for my 1985 G20! Also looking for a suitable solution for this. I do plan on hanging some things from my ceiling and would like for the structure not to fail again.

Not to mention there is so much resonance on the highway with that roof panel flapping around.

Search Topper tape. This is foam tape with adhesive for Camper tops on pick ups.
Made to seal and quiet the seam in all weather conditions.

Also, a bead of silicone after. Silicone has come a long way in 40 years.
I seal all of my outdoor signs with it. lasts for 20 years.

I've seen topper tape, truck camper tape, etc. but everything I'm finding either too thin, only sticky on one side or not sticky enough for a long-lasting solution. I need something pretty thick that will be strong enough to stick the support back to the roof like it was from the factory.

The only thing I can find that seems promising is a true "Panel-Bond" glue, but they all say that the surfaces must be bare metal and that is going to be nearly impossible in this position. It almost needs to be an expanding foam of some sort, but I'm not sure where to start there.

Hi Jason,

Hmm, interesting development. How about a thick epoxy type adhesive like J B quickweld, with a ShoeGoo chaser around the edges? Prop it up tight against the skin.
Some Plumbers adrasive strap for cleaning/soldering copper pipe would fIt between the rib and lid, I'd think, for paint removal. Sure makes the copper tubing shiny! But clean out all that crap first. Lol.

Looking good! More progress!!!

Happy Friday and Good Wrenching!

A bit late to the dance here, but what I used were several 3M one and two-part products on my ceiling bows, strainers, pillars, and hood.

There are two two-part foams; the 3M #08463 is dark gray and somewhat flexible, and is closest to the material in your picture. Here's a closeup of some I dropped:



It is specified for precisely that sort of panel to panel and panel to frame element damping. It is OEM approved for use in collision repairs.

The 3M #08458 pillar foam is yellowish and quite rigid. As it's name indicates, it's target is filling the void in door pillars.

They both are self curing, so they can be used to fill voids where there's no air. That's *very* different behavior than the inexpensive canned foam sealant you get at home improvement stores, which will remain fluid indefinitely without air and specifically moisture to cure it.

They also both cure as closed cell foams, providing the skin on them remains intact. However, if you puncture or sand down the skin, they can absorb moisture, so it's best to apply carefully then leave these alone post cure! They are both paintable.

These foams do expand appreciably during curing, though glacially slowly compared to canned hardware store foams, so apply with expansion in mind, and allow for air and any excess foam to exit any cavities. If you don't, you could experience bulging of panels over the foam filled cavities as pressure builds! I saw anywhere from 1.5 to 3 times increase in volume, depending on application temperature. You can always go back and apply more if necessary; these will stick to cured foam, so layering is perfectly fine and is encouraged.


In areas where resonance was a substantial factor I used the 3M #4274 NVH ("noise, vibration, harshness") compound, which is a mass-loaded dark violet medium flexibility material, reminiscent of a fully cured dark colored RTV in appearance.



The dual plunger applicator gun is a 3M #08571. They could be had for under $50 when I purchased mine





-Yep, I also used it along the wheel arches, to help quiet down the walls. Even with all the strainers and damping, they needed a bit more effort.


It may be worth checking to see if the spot welds around the center of the ceiling bows are still intact if you're experiencing obnoxious amounts of resonance. Filling the gaps with any of these compounds will go a long way towards fixing, or even improving upon it, but is a seriously expensive option; the 3M products require an applicator gun, run around $40 per tube, and I used several dozen tubes in my maxi van.

The hood required clobbering power:



That being said, a large part of why I used so much is that I added 6 more bows and a similar number of strainers.







-There simply weren't enough original bows and strainers to quiet down that big ceiling and the sail-like walls; they only used enough to minimally support the structure. There's no substitute for a sound structure; I'd recommend performing structural upgrades long before wading into the world of CLD damping pads. Those lightweight bows and strainers do far more good than the heavy and costly CLD pads.

Peculiarly, and somewhat perversely, the region above the driver and passenger seats was especially ghastly; I had to call in a tactical nuclear strike on that area:





Now I can hear myself think...

I filled the additional bows with foam before even installing them:




Was it all worth it? See for yourself in these before and after examples of wideband spectral curves I collected from several of the wall panels:

Before

After


Before

After



And a couple of ceiling panels:

Before

After


Before

After



That's a lot of decibels of noise energy...

I hope that provides you with some additional ideas!

Holy crap!! What a quality post!! Thank you! (Although I did think your first picture was something else at first lol)

I think that I'll do a bit more research on the 3M foam stuff to quiet down my existing bows. I already have the gun from doing the seam sealer, so that's nice lol.

And I hadn't thought about adding more bows, but that's a pretty good idea too since i will probably be hanging some stuff from the ceiling and the extra support would definitely help.

Seriously...late to the dance or not, that's some awesome information. Thanks!

+1000

Yup. Ram4ever has some awesome information. I listen when he speaks.