moisture under paint

[rocketman]

I posted this in the Details and Wax section, didn't get many replies. What can I do about a small area on our 1997 Lumina that has obvious moisture under the paint, evident by the blistering or bubbling on the vehicle? There are about 5-7 small blisters (size of a large screw head) in an approximately 2 inch diameter area. Also, when pressed hard with my finger, some water actually comes out. It is in an area about 5 inches below the gas filler hole door, almost where metal meets a plastic (fibreglass?) panel. The vehicle only has 68,000 km on it and the rest of the vehicle is in mint condition. What should I do, and how did this happen?

 

[rocketman]

I could pick at the blisters, yes. What would that show me besides the moisture? I did think of doing what Matt S stated, but wasn't sure if it was the right thing to do. Since it is a small area, I assume Matt S means sanding by hand and not grinding. I don't feel comfortable grinding (it's my wife's car - she'd kill me if I made it worse!!!) If I did a perfect job, would this solve the problem?

 

[Matt_S]

Unless you really know what you're doing, you'll always be able to tell it's been patched. I've done patches to my cars before and, while it's not perfect, it sure beats seeing a rust spot. If you're worried about your abilities, getting it professionally fixed would be the best way to go. If you want to have a go at it yourself, autopia.org has a lot of information on doing that kind of work.

 

[brianl703]

Order the correct touchup paint and primer for your vehicle from http://www.paintscratch.com

Also order the Langka complete paint chip repair kit from http://www.langka.com and also order the prep pen.

Use the prep pen to remove the rust.

Apply primer to the bare metal.

Apply touch-up paint to the primer after it dries.

Continue applying touch-up paint until it's even with the surface of the surrounding paint.

Use the Lankga to remove excess paint if you've put too much in and there's a "blob".

I've done this to repair a rust spot on the roof of my car and the results weren't half-bad given that I made no effort to make it look nice.

 

[Kestas]

I can only guess, but perhaps it's corroding from the inside out, or the panel was previously repaired and moisture got into the plastic filler used on the top layer. Can you dare pick at one of the blisters?

 

[Matt_S]

Every time I've seen what you're describing, it's a result of the metal rusting underneath the paint. It needs to be sanded to bare metal, patched (if necessary), then primed and painted if you want it fixed properly.

 

[Dark Jedi]

if its below the gas lid. have you overfilled the vehicle alot? I have heard it can soften the paint and moisture could have gotten behind. but you need to get it fixed before your small area turns in to a large area. I would also goto the chevy dealer and ask them if they have seen or heard about this. and show them. I am sure they wont cover it but they might if its a known defect.

 

[Amkeer]

Your clearcoat is delaminating from base coat. No easy fix other than color and clear again by a bodyshop. I have same problem on the roof of my 4-Runner except its not delaminated.

 

[chas3]

its rusting from behind. the gas filler door also has a bracket welded to the body from behind to hold the top end of the filler pipe going to the gas tank. one of those welds (or the bracket, something in that area) has started to rust. you need to take a look behind. the original problem must be found.

its not an easy fix for an amateur. you will need a pro.