I was just browsing one of the other posts on fixing later model bodies, and wondered about a repair fix for spiderwebbing on my 92. There are several, like on the hood, rear top deck (conv), and back corner. How do you repair them, and how can you stop them in the future. In the past on the older glass bodies you could add a couple of layers of glass on the underside, then bevel the crack, fill, and smooth. Are there more permanent repairs than just filling?

 

 

Is this an uncommon problem, or are others sitting and watching?

 

I'm not sure of how to repair the spiderwebbing, I'll wait for others to chime in on that, but I believe spiderwebbing is just the nature of the beast. I don't think there's any way to get around the spiderwebbing effect, the SMC undergoes a lot of flexing, and I think some spiderwebbing is inevitable on all of our vettes. It's not a matter of if we'll get spiderwebbing, rather, it's a matter of when.

 

Isn't there and additive in the paint specifically for flexing?

 

Would a camber brace and cross bar which I though reduced flexing of the body help?

 

Come to think of it, I'm sure a camber brace or cross bar would help with reducing the spiderwebbing effect. (But don't quote me on that.) Those of use that don't have a brace or bar are well aware of the amount of flexing and shaking that our vettes go through, especially when the top is off.

I'm not sure about GM paint specifications, but here are some specs on SMC:

-Impact Strength: 8-13 ft-lbs/in

-Flex Strength: 18-34 KPSI

-Flex Mod: 1.5-2.1 KPSI

-Tensile Strength: 8-18 KPSI

-Compressive Strength: 24-32 KPSI

-HDT @ 264 PSI: >500°F


Now, it's just a matter of the varying flex pressures our vettes actually undergo, and the age/specs of the paint/paint additives.. I'm not sure if cold cracking is a common occurence either. But I have read various threads on the forum discussing cracking after encountering some bitter cold.

 

Id like to add if you have the removable top, it is best to have the solid one as it does not flex as much as the clear one does.

 

I'll take a shot at it.

What you're seeing is a paint problem. A problem of the paint not now able to deal with the amount of flex.

All Vettes are painted with DuPont paint (at least last I read), and DuPont has done extensive testing to formulate their products to specifically address this flexing issue.

Think about this: Do you believe that GM would continue to use DuPont products if that gave unsatisfactory results??

If you go to the DuPont site and do a little research you'll see that most of their high-end products don't require any additives to deal with flex. It's incorporated in the primer, surfacer, base and clear. As am example, one recommendation I can recall is 12305s, which is pricey for the amount you receive (pint?), so many skip it. HEY, DON'T!

In your case, I believe refinishing is what's called for.

Use EVERY DuPont (why would you use something else!??) RECOMMENDED product. Don't let the refinisher use his own (special receipe; witches brew) way of doing it.
DuPont wants all their products to perform to the expectations of their customers. Do you actually think they want to have dissatisfied customers??

I'm aiming this primarily at those who advocate other products; not at you. I'm addressing this because I've read SO many posts from owners saying their painter wants to use (FILL IN THE BLANK) products; decrease the activator by X amount, etc.

I believe you need to have it sanded down and re-finished using nothing but the latest DuPont products and follow their SPECIFIC instructions and recommendations.

Just my thoughts, even though they are somewhat emphatically stated.

Jake

 

You made good points Jake.