I was looking to purchase a red '69 roadster and noticed paint bubbling in the door and front. The door bubbling is pretty prominent, considering the car is nicely detailed and put on a showroom floor. It's located at around the middle (lengthwise) of the door and the upper portion, where it meets the glass. The front bubbling is located in between the left (or was it right) headlight crease and the hood's crease.

If the car is made of fiberglass, what gives? Are there any metal braces in those areas that could corrode and show through the fiberglass? What could cause the paint to stop adhering to the body to cause the bubbling? How much would that depreciate the value? Hoping for the more the better since I'm purchasing it... :D Also, how expensive of a fix is it? Since I would plan to eventually fix it. Is it a deteririorating condition in which the corrosion is going to progress through the rest of the car within the next couple of years?

I live in Northern California, so salt on the road is non existent and rain is not too abundant.

 

There's a lot of metal under the fiberglass of a Corvette. They have a welded steel birdcage. The inner doors are metal stampings. Only the outer door skin is a fiberglass panel. There is a large metal headlight bar under the nose in front of the hood. Unless there is something on the fiberglass causing the paint to rise, in all likelihood you are seeing the effects of rust on the metal panel beneath the fiberglass. Can you get some pictures? It would help if we could see what you're talking about.
:)


[Modified by Easy Mike, 12:22 PM 10/24/2001]

 

I'll go to the dealer today and get some pictures.
What is an "acceptable" amount of corrosion to be found in a car in between fair and good condition? Is there such a thing or is corrosion something that immediately rates a car at fair (driver condition)?

I also saw some other things that kind of bothered me. I'd sure appreciate it if you took a look! Again, I'll work on getting pictures today.

Thanks for your answer on this post and the P.O.P post! :cheers:

 

There are several places where the body parts were riveted together - a line behind the lights where the nose is attached to the front body section. The rivets corrode and push up the paint. On the good side this probably means that you're dealing with original panels if you can see the row of rivets up there and the car has probably not had a new front clip. ;) Other bubbling can just be crappy GM orange peel. I've got a whole crate of it on my front hood. :U

Check the front windshield pillar posts for corrosion. They're notorious for going out and the water could also have dripped down the pillar posts into the birdcage. This is corvette cancer. Also check the frame in the rear kickup area by the rear wheels. Check the body mounts too. My '70 was bought from the original owner with 44k miles on it. All the rust was cosmetic - and nothing structural. I have a bunch of undercarriage 'before' pictures which I took when I inspected the car before purchase. They might give you a reference point. Look in the undercarriage section. Click on the shark in my sig line to go to my homepage.

 

Wow thanks for the insight!

It definitely looks like the bubbling in the front is from the rivets you discribe. They are evenly spaced and span almost the entire length of the front portion. The A-pillar posts look OK. I took pictures of them to get a better idea, but it looks fine. The car has 75k miles on it or so. The rear kickup area looks really clean too. Still very curious about the bubbling on the door.

Will the rusting where the rivets are spread? Is it something that I would be able to "live with" or is it something that should be rectified at the risk of serious damage?

Not yet able to put the car up on a lift. No t until I've made up my mind that this is what I want.

I'm going to try to put the pictures up by tonight (Pac. Stand. Time) but it's so slow to download!

 

Pictures I promised...
One is zoomed in, the other isn't. They are pretty detailed pictures, so I don't know how big they will show.
http://temp.corvetteforum.net/c3/stickanddice

Had to create the page in a hurry, so just scroll to the bottom to see the pics. Sorry about the template material that's still there.

 

That looks more like some foreign material under the paint more than a rivet head that is coming through. My 72 has two or three rivets that can be seen at the front of the car, just below the headlights. The paint is bubbled slightly in a perfect circle about twice the diameter of the rivet. On the other hand, my friend painted his 73 and months later he started getting some blistering in odd places. Paint would blister and then peel off. He had some ugly cancers before we did a complete restrip and repaint. He cleaned the bare body several times with lacquer thinner and then a final prep cleaner before we even thought of paint. Are you sure this isn't an irregular bubble associated with some poor painting? If it is you won't be happy when more of it starts coming off.

Gary

 

S&D, from your pictures, it's still difficult to understand the problem, i.e. "bubbling paint". I am interpreting both pictures as being of the door, but the characteristics of either picture are not obvious in the other.

In the first picture, it appears that the dark spot is either bare fiberglass (but my 70 door skins are a lighter gray) or a black color coat or primer. It does not appear from this picture that the surface of the dark spot is raised, it appears that the paint simply didn't adhere to to substrate at that location. I would try to check hidden areas to see if the dealer has attempted a cheapo sand and repaint to return the car to its original color (more valuable in it's original color, doncha know). Also, if there were oil stains on bare fiberglass in that area for the last repaint, you can expect the paint to not stick there.

The second picture does seem to show a random raised pattern in the door skin. There is no metal behind the area shown, so I would be concerned about a bad repair just becoming visible. At best, I believe you are looking at stripping the door to bare glass and refininshing as Gary suggested; at worst, you may have to redo a bad repair and refinish.

On the front end, I am not sure about the repair process, but expect the corroding aluminum rivets will have to be replaced to eliminate the problem; simply grinding down the raised areas, rebuilding the contour,and refinishing is not going to fix the problem long term.

Many of these old cars are going to have problems like these. It doesn't mean that the problems should scare you off the car, but it should certainly be a bargaining lever to get the price down.

 

The pictures you're seeing are pictures of the door's bubbling paint. I didn't bother with the rivets in the front because I'm pretty sure that rust is what it is (thanks to you posters!).

If this is due to a poor paint job, should I expect this sort of thing to eventually come up everywhere?

 

Sorry for being so vague...They are both pictures of the same door. It was difficult to capture the bubbling with my camera, so I tried to show the background images reflecting from the paint getting distorted to show the bubbling. It is definitely raised. There are some other signs that kind of have me worried. For example, there is a deep scratch at either side of the car, under the "gills" close to the bottom. You can see the paint has been scratched to the body. Paint is cracking in some of the edges etc.

How much would it be to properly paint the car over? And how would that affect resale value? I don't suppose that a car without original paint, but original color would lose too much value...

 

If it were me, S&D, I wouldn't be concerned that repainting would decrease value unless the car is highly original and is a likely "Bowtie" candidate. In that case, loss of the original paint would eliminate it as a candidate in that cateqory. In NCRS flight judging, a repaint will incur no deducts if it is indistinguishable from original finishes in appearance.

It is more likely that a quality repaint in the original color replicating the original appearance would ENHANCE the value of the car. Few of these old cars still have the original paint, and if they do, they don't look too fine. In this case, my opinion is that I certainly wouldn't be paying extra money for the car still having its' original paint; far from an advantage, the dealer would have to offer me some incentive to take the car.

The costs for completely stripping and refinishing a Corvette vary widely around the country, and also depends on the quality of the shop and its workload. My opinion is that an 'order of magnitude' cost is going to be about $5-7K.


[Modified by Chuck Sangerhausen, 1:40 PM 10/25/2001]

 

The two most prominent problems with 69 are these two things. The doors on a 69 at least later production cars were the first panels changed to SMC compound. More and more panels were changed untill 74 when the whole body was SMC. The factory materials were not very compatable with SMC. Therefore lots of times you will find 69s with good paint except on the doors. It just didnt adhere very well. The other is the problem with corrodeing rivits which is common on northern cars especially.

 

Wombvette, your comments about SMC being used for door skins in 69 are interesting. That is the first time I have ever heard that, but hopefully I learn something every day.

I have wondered if the lighter gray of my 70 doorskins could be explained by SMC, but believing that SMC wasn't introduced until 73, my concern was that the door skins may have been replaced. If the door skins are SMC, then polyester based bonding adhesive cannot be used to bond the skins to the metal frames, isn't that correct?

The T-tops are also the same shade of gray, and presumably are also SMC. One of the T-top skins appears to have some kind of black debris that was introduced during the molding process, and the flow of the material during the molding is evident from the debris lines. Interesting. :)

 

Each year more parts were changed to SMC. The first being the door skins on later 69s. By the end of 73 just about everything but the rear upper panel was changed. With the rear change in 74, that panel was changed.
The early SMCs will bond with posyester but the bond is not as good as it is on polyester. The factory did use the polyester to bond the bodies together, but if you have ever seen on of these cars hit from the side in the front frame horns you will get an idea of how the bond is not very good. The body will just pop off the cowl and split down the seams.