C-3 Body Repair Question

[Don W.]

I have question on my '69 "driver".

If I run my hand with some slight pressure across the top of right front fender where it meets the hood; I can hear a popping sound. When I place a light in the right side wheel well and look up, I can see that there is some separation where the panels meet at the top. If I look at the other wheel well; everything looks bonded together.

Is there any easy way for me to re-bond these panels; such as mixing up a 2 part epoxy and forcing it into the gaps?

Sorry I don't have all tech names for those parts and thanks for your input.

Don

[Chuck S.]

Re: C-3 Body Repair Question

The inner fender is not bonded laterally across the upper fender (surround) at the top...there is a rubber seal at the front and back of each inner fender to prevent splashes from leaking from the wheel well. The fact that you can see daylight on one side and not the other only means the seal on one side is more deterioated than the other.

The inner fender is only bonded to the outer fender at the hood ledge, the front of the wheel well to the side of the fender, and at the rear of wheel well to the side of the fender. There is NO support or bond joints between the rear of the inner fender and the plenum bulkhead. The best drawings of the plenum bond areas are shown in the AIM in UPC 1, Sheets A14 and A16...not ideal, but it will give you an idea of what it looks like on the inside.

You can probably repair the bond at the plenum bulkhead if you're clever. You'll need to remove some stuff to access that cavern inside the fender...the vacuum reservoir will have to go (no small task), and maybe the master cylinder and power booster (Oh, boy). If that is the case, and you have long arms, you can try to access the joint from the bottom by removing the bottom triangular splash shield.

Unless you plan to use a modern automotive structural adhesive like Lord's Fusor 127, I would NOT use epoxy in this case. Even though it's a driver, I would still use the same polyester bonding adhesive used originally. You can order it from The Corvette Image, tinted black just like the original, for about $30-$35 a quart. The two-part epoxy resin applicators easily available at Home Depot will make it hard to place the adhesive, and once there, the catayzed liquid will not fill the joint void like the polyester paste. And, No, I wouldn't use that two color putty that you knead together either.

If possible, first try to rough up the bond joint as much as you can using 36 grit sandpaper wrapped around a paint stirring stick. When you feel like you've roughed it up well, blow the joint with air to remove any dust and loose particles. Then catalyze the polyester bonding adhesive using about 12 drops of liquid MEKP catalyst to each golf-ball-sized glob. Better mix about three to four golf balls worth of adhesive...you don't want to come up short; better to throw some away than not have enough.

Once you have mixed the catalyzed adhesive thoroughly, use a narrow-bladed putty knife to scoop up a 1/2" diameter bead on the very tip of the blade. Push the putty knife up to top of the fender near the plenum bulkhead, then move the putty knife rearward to force the adhesive into the plenum bulkhead joint. Keep poking it in until you're sure the joint void is filled...you can reach inside the plenum to feel if the adhesive has come through. Once adhesive has come through all across the broken joint, use your latex gloved finger to smooth the joint

If the problem is from broken bonds that are further aft, repair will be tricky and will require a lot more thought. The usual spot of separation is the very tip of the fender at the windshield. You may be able to see deflection of the fiberglass wherever bonds are broken when you press on the fender.

[Chuck S.]

More...

After thinking about your post some more, I've decided you may be describing separation of the continuous overlapping bond between the inner fender and the upper fender (surround) along the hood ledge. In either case, I'm not sure how you could be seeing daylight inside the fender well.

The adhesive and techniques for mixing will be the same, but you may have to grind off broken excess bonding adhesive from the inside of the wheel well to prep for bonding. My experience is you will not need any screws, clamps, or cribbing to hold this joint closed while the adhesive sets up...the natural position of the original body assembly is enough, but keep an eye on your hood gap just to be sure. You WILL want to make sure the level of the fender at the hood ledge matches the hood contour...if not, adjust and support as necessary before you mix the adhesive.

[Don W.]

Re: More...

sound complicated, maybe I'll wait and have a pro look at it when I take it in for other work. Thanks for your time and advise....Don