: Rust bubble under vinyl top

10-17-08, 11:24 PM
I have a rust bubble on the right c-pillar of my car. I know what's involved with fixing it the right way(rip up old top, weld, paint, put on new top, pay $800). The top is in really nice shape except for the rust bubble.

I got the crazy idea that maybe if I whacked it real good with a rubber mallet I could get the metal to lie flush and make it less noticable. Or is this a bad idea, will I make it worse(like ripping the material)?

10-17-08, 11:31 PM
I have the same problem in the same spot and that sounds like the best idea I've heard so far. Do you think that would accelerate the rust growth?

10-18-08, 08:19 AM
The problem with rust is that it is like cancer. If you don't take steps to eliminate it from an area, it will spread to the surrounding area and continue it's growth. The oxidized metal becomes layered and acts like a sponge to draw in moisture, and the rust continues it's creep into the good metal around it. You have to go in there and play surgeon to remove the rust. Some grind it out, which heats the metal and tempers it. If it gets too hot, it will oxidize at that point and a year after you have finished the job, you will see bubbles in that area. Others use sand blast too remove the metal. This works pretty good, but you have to seal the bare metal soon after the blasting or the rough surface of the metal will quickly start oxidation, especially on the humid day. _Proper preppping of the metal is crucial. Others will use acid, if the rust isn't too deep. This etches the metal. It has to be neutralized after application or the process will continue just like the oxidation that you are trying to repair.
All this makes the process of rust repair very frustrating. Metal prep before sealing is the main process concern to ensure it won't come back. Also, there are so many products out there claiming to address this problem, it gets confusing. Do research and use good quality products. Cost should be a secondary concern in this area. Go to car shows and talk to people who have had success at this. They'll tell you what products they had the most success with.

10-18-08, 06:14 PM
Ewwww.... I had that problem on my 90, but the top needed to be replaced, so i fixed it before the new top went on.

As far as hitting it with a hammer. Chances are if its the original top, and hasnt started cracking yet, smashing it wiht a hammer may just do that. It might be soft when you touch it, but hitting it with such force may crack the material. Its like dash pads. They may not be cracked, but since they take so much of a beating from the sun, that one time you get pissed at that guy that cut you off, and you smack the dash... OUch....

I would say no, dont do it. I dont see it doing anything if it didnt crack anyway. There is no where for the rust to go, its not like you can hit it, or scrape it and it falls off. It will still be contained there. Plus if its been there awhile, it probably left its "memory mark" in the top material. Like when you get a bowed in filler panel, and drive around and not pull it out. The platic takes memory to that position, and will never return to its original shape.

10-18-08, 10:57 PM
I say beat it with a rubber hammer. Just be gentle.

10-19-08, 10:54 PM
If you're willing to take the risk with hurting the vinyl, go for the hammer method. It may do nothing to the vinyl at all. If you're not willing to take the chance on hurting the vinyl, seems like you only have one option left to chose.


10-20-08, 12:12 AM
Here's a thought. Maybe you could remove the rear sail panel and get to the metal from the inside. :hmm:

10-20-08, 01:03 AM
Here's a thought. Maybe you could remove the rear sail panel and get to the metal from the inside. :hmm:

Maybe that's the way to go. The headliner is starting to sag as well, and I really think that the rust came from moisture from the sunroof not draining properly. I know sometimes I'll get a little bit of water coming in around the right rear door, if its raining really hard and the car has been sitting.

10-20-08, 02:33 AM
I can vouch for that. My headliner was sagging in my '92. But it was a recently done job, so I wondered. Then while replacing it, a pool water poured over me from the sagging region. It was from the plugged sunroof drain lines. Water was forced over the headliner board, and trickled down the c-pillar into the carpet.

Sunroofs can be such a pain! :thepan:


10-20-08, 09:33 PM
Here's a thought. Maybe you could remove the rear sail panel and get to the metal from the inside. :hmm:


10-20-08, 10:20 PM


10-22-08, 09:13 PM
My 90 FWB doesn't even have a sunroof, but when it rains, it comes in from somewhere above the windshield. It's not the windsheild itself, though. The top may be new, and the guy i had testing the windshield said that sometimes when tops get replaced, they won't tell you about rust bacuse they might lose the job altogether. I just don't want to ruin my interior!