surround beam repair

[Dennis D.]

About ready to replace the beam and bonding strip on my 70. (deer damage). I received the bonding strip today. I noticed there are recessed holes the size of a nickel and thickness of a dime on the top side. I assume the pan head rivets install down and through the steel beam. Leaving the head of the rivet flush with the bond strip top surface.

I seem to remember talk about bumps from the rivet heads showing through the paint after some time. I would have thought the rivets would need to be installed through the top surround for that to happen.

Do I have the right bonding strip?(GM 3930134-gr1.263) And are the rivets installed through the strip and beam, then the 2 pieces bonded to the underside of the surround? Then the fiberglass b/strip get bonded to the fiberglass surround?

Are the rivets used to connect the 2 dissimilar pieces, (glass and metal)? Or is there an adhesive for this now? Eliminating the need for the rivets. If that's the case can I leave the old bonding strip and adhere the new beam to it?

[Tracy C.]

Re: surround beam repair

While I can't speak for part numbers on your application, I've done this job before. The bond strip is riveted to the metal reinforcement only. You need the large flat headed rivets availible from Corvette supply houses for this job. Yes the end product will leave the rivet head flush with the adjacent bonding strip.

What eventually happens in most cases is the aluminum rivet head corrodes and causes markoff in the upper surround panel. You can reduce this occurance by first painting the rivet head with a good epoxy primer and then using liberal amount of adhesive over the rivet location to prevent moisture migration.

There are two part epoxy adhesives that will bond metal to fiberglass. Hysol 9309 or 9394 will do the job fine, but I'm not sure where one might find these availible. (We use these adhesives in the aircraft biz all the time)

I'd go with the rivets first like the General did as you will be able to see this area when all is said and done. You want rivet butts and not adhesive squeeze out visible in the hole locations. Just take the precautions described above.

Good Luck,
tc

[Dennis D.]

Re: surround beam repair

TC

Is the bond strip and metal beam bonded together with adhesive as well as rivited? Any secrets or precautions removing the old bonding strip from the surround? Thanks for the info, Dennis

[Tracy C.]

Re: surround beam repair

The metal reinforcement is typically not bonded to the bond strip. I suppose you could if you wanted, but I wouldn't recommend it.

I been told a heat gun facilitates removal of a bonding strip. I've never tried it. If you do, take care not to overheat the surround. (or any part you want to keep)

I usually just grind the old piece away to nothing. You will need to remove any residual adhesive with this method anyway. Be sure to wear safety goggles and a breathing mask (like painters wear in the booth) Wouldn't hurt to wear long sleeves and tape the wrists down to your arms also. If this is still on the car, you will be working in some pretty confined areas.

This type of work brings a new spin to the term "Corvette itch". You gotta love it!!

I would definitely remove the old bond strip though. Remember the original rivet heads are still sandwiched between the surround and the bond strip. The potential for corrosion exists as long as they are present.

[Dennis D.]

Re: Thanks *NM*