Does A Paint Bubble Always Mean Rust?

it's hard to say with out being there to see it, from the description that is a large area. it may be a previous repair job coming loose i.e. bondo. if it is rust, well... ignoring rust is like ignoring cancer, it will continue to spread and only get worse. take it to a reputable body shop/restoration facility and see what they say.

 

Most likely.... I had a bubble grow from the side light as well..........surface prep was not good....

BUT they can spot repair and flash blend paint really well these days, find a good paint shop and take it in!

 

Well, I would hazard a guess that it is probably rust if it is a bubble. Or at least, rust must be suspected until proven otherwise.

Just as a rhetorical question - has anybody seen such a big bubble (plum size!?) that was NOT rust? Or, such a thing on a fiberglass bodied car?

My opinion is to go ahead and fix it, and just do a local area paint redo for the time being if you don't want a full car repaint. That cannot look as bad for driving or events as such a big bubble that you have described, and you have the peace of mind knowing exactly what is underneath it all.

 

James assessed it right! Bubbles are bad news, any way you look at it. Air gets in there , fine rust soon follows, etc. Looks like hell just the same, so might as well burst it, and sand down accordingly, prime if you want, then decide which paint shop you want to blend it in surroundings.

 

There is a very slight chance you have the first steel Ferrari that doesn't rust.

Of course it's rust! The sooner you fix it the less it will cost.

If only all the Technical Q&A questions were this easy.

 

There are two questions to answer:

-Does a paint bubble always mean rust?
The answer is no. Bubbles can often mean there's rust forming underneath, but they can also mean poor prep (such as dust underneath,) poor paint adhesion, or even a fiberglass section delamenating. (I had several paint bubbles on my departed '69 Corvette.) It can also be a sign of thick bondo underneath that is coming loose.

-In your description, does it sound like you have rust?

Probably. Areas that get wet/muddy and tend to trap that moisture are the areas that rust first.

 

Please bear in mind that in 1980, the Italians were building cars out of steel provided free by the Russians in return for a license for the Russians to build the Fiat 124 rebadged as a Lada.

 

My car's original paint bubbled on the rear of the car from the heat.... I was worried that it was rust but it wasn't... 95% of the time it is rust though... As someone said, either way it is bad...

 

Yep, and they were using it for Fiats, Alfas, .....Ferraris too?????? Dont tell me!!! LOL

 

My 308 had a small bubble right where you explained, and yes it was rust. Actually when I first looked at it I thought it was just some crap under the paint because it was hard but as I sanded that area rust appeared. Since I do my own body work I fixed it myself got it early. A few 308's I was looking at before I bought mine had small bubble in the same place must a problem area.

Jim

 

Another place they like to rust is under the fiberglass in the front wheel wells, It may look fine but chances are it's there. Mine was in a heated garage for 16 years and it still has some minor rust.

Jim

 

Well that's a surprise for me and good news for you!

 

I too am surprised, but it is an excellent thing that it turned out that way.